Publications

Citations >7,700, h index = 43 (Web of Science)
Citations >10,500, h index = 52 (Google Scholar)
(as of May 25, 2018)

2018

180. P. C. Loewen, J. Switala, J. P. Wells, F, Huang, A. T. Zara, J. S. Allingham and M. C. Loewen. 2018. Structure and function of a lignostilbene-alpha,beta-dioxygenase orthologue from Pseudomonas brassicacearum. BMC Biochemistry 19: 8. doi.org/10.1186/s12858-018-0098-4. View PDF

179. P. C. Loewen, P. M. De Silva, L. J. Donald, J. Switala, J. Villaneuva, I. Fita and A. Kumar. 2018. KatG-mediated oxidation imparts reduced susceptibility to kanamycin. ACS Omega 3: 4213-4219. View PDF
Supplementary Information: View PDF

178. A. Ivancich and P. C. Loewen. 2018. Electron transfer in catalases and catalase-peroxidases. In Robert, G. and Watts, A., European Biophysical Societies (eds), Encyclopedia of Biophysics, Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-35943-9_51-1. View PDF

2017

177. D. Vila-Vicosa, B, Victor, J. Ramos, D. machado, M. Viveiros, J. Switala, P. C. Loewen, R. Leitao, F. Martins and M. Machuqueiro. 2017. Insights on the mechanism of action of INH-C10 as an anti-tubercular pro-drug. Molec. Pharm. 14: 4597-4605. View PDF

176. M. Machuquerio, B. Victor, J. Switala, J. Villanueva, C. Rovira, I. Fita and P. C. Loewen. 2017. Catalase activity of catalase-peroxidases is modulated by changes in pKa of the distal histidine. Biochemistry 56: 2271-2281. View PDF

175. D. M. Fernando, P. Chong, M. Singh, V. Spicer, M. Unger, P. C. Loewen, G. Westmacott, and A. Kumar. 2017. Multi-omics approach to study global changes in a triclosan-resistant mutant strain of Acinetobacter baumannii ATCC 17978. Int. J. Antimicrob. Agts. 49: 74-80. View PDF

2016

174. M. Nandi, C. Berry, A. K. C. Brassinga, M. F. Belmonte, W. G. D. Fernando, P. C. Loewen and T. R. de Kievit. 2016. Pseudomonas brassicacearum strain DF41 kills Caenorhaditis elegans through biofilm-dependent and biofilm-independent mechanisms. Appl. Environ. Micro. 82: 6889-6898. View PDF

173. J. Wiens, R. Ho, D. Fernando, A. Kumar, P. C. Loewen, A. K. Brassinga and W. G. Anderson. 2016. Complete genome sequence of the Rhodococcus species isolated from the winter skate Leucoraja ocellata. genomeA 4: e00918-16 View PDF

172. W. Behrens, T. Schweinitzer, J. McMurry, P. C. Loewen, F. Buttner, S. Menz and C. Josenhans. 2016. Localisation and protein-protein interactions of the Helicobacter pylori taxis sensor TlpD and their connection to metabolic functions. Scientific Reports 6: 23582, doi:10.1038/srep23582 View PDF

171. D. Sun, S. A. Crowell, C. M. Harding, P. M. DeSilva, A. Harrison, D. M. Fernando, K. M. Mason, E. Santana, P. C. Loewen, A. Kumar and Y. Liu. 2016. KatG and KatE confer Acinetobacter resistance to hydrogen peroxide but sensitize bacteria to killing by phagocytic respiratory burst. Life Sciences 148: 31-40. View PDF

2015

170. M. M. Galka, N. Rajagopalan, L. M. Buhrow, K. M. Nelson, J. Switala, A. J. Cutler, D. R. J. Palmer, P. C. Loewen, S. R. Abrams and M. C. Loewen. (2015) Identification of interactions between abscisic acid and ribulose-1,5-bisphosphate carboxylase/oxygenase. PLoS One 10(7):e0133033 doi:10.1371/journal/pone.0133033 View PDF

169. I. Fita, X. Carpena and P. C. Loewen. (2015) Catalase-peroxidase (KatG) structure and function. Heme peroxidases. ed. E. Raven and B. Dunford

168. M. Nandi, C. Selin, A. K. C. Brassinga, M. F. Belmonte, W. G. D. Fernando, P. C. Loewen and T. R. de Kievit. (2015) Pyrrolnitrin and hydrogen cyanide production by Pseudomonas chlororaphis strain PA23 exhibits potent nematicidal and repellent activity against Caenorhabditis elegans. PLoS One 10(4):e0123184 doi:10.1371/journal.pone.0123184 View PDF

167. I. Fita, P. C. Loewen and X. Carpena. (2015) Catalase-peroxidase:KatG. Encyclopedia of Inorganic and Bioinorganic Chemistry ed. R. A. Scott, John Wiley: Chichester. DOI: 10.1002/9781119951438.eibc2273 View PDF

166. P. C. Loewen, J. Villanueva, J. Switala, L. J. Donald and A. Ivancich. (2015) Unprecedented access of phenolic substrates to the heme active site of a catalase: substrate binding and peroxidase-like reactivity of Bacillus pumilus catalase monitored by X-ray crystallography and EPR spectroscopy. Proteins 83: 853-866. View PDF

2014

165. P. C. Loewen, Y. Alsaadi, D. Fernando and A. Kumar. (2014) Genome sequence of Acinetobacter baumannii AB031, a tigecycline-resistant clinical isolate from bloodstream infection. genomeA 2: e01036-14 View PDF

164. P. C. Loewen, Y. Alsaadi, D. Fernando and A. Kumar. (2014) Genome sequence of Acinetobacter baumannii AB030, an extreme drug-resistant (XDR) clinical isolate. genomeA 2: e01035-14 View PDF

163. D. Fernando, W. Xu, P. C. Loewen, G. G. Zhanel and A. Kumar. (2014) Triclosan can select for an AdeIJK overexpressing mutant of Acinetobacter baumannii ATCC17978 that displays reduced susceptibility to multiple antibiotics. Antimicrob. Agents Chemo. 58: 6424-6431. View PDF

162. P. C Loewen, J. Villanueva, W. G. D. Fernando and T. de Kievit. (2014) Genome sequence of Pseudomonas chlororaphis PA23. genomeA 2: e00689-14 View PDF

161. K. D. Miner, T. D. Pfister, P. Hosseinzadeh, N. Karaduman, L. J. Donald, P. C. Loewen, Y. Lu and A. Ivancich. (2014) Identifying the elusive sites of tyrosyl radicals in cytochrome c peroxidase: implications for oxidation of substrates bound at a site remote from the heme. Biochemistry 53: 3781-3789 View PDF

160. P. C. Loewen, X. Carpena, P. Vidossich, I. Fita and C. Rovira. (2014) An ionizable active site tryptophan imparts catalase activity to a peroxidase core. J. Am. Chem. Soc. 136: 7249-7252. View PDF

159. P. C. Loewen, J. Switala, D. Fernando and T. de Kievit. (2014) Genome sequence of Pseudomonas brassicacearum DF41. 2014. genomeA 2: e00390-24. View PDF

158. J. Villanueva, J. Switala, A. Ivancich and P. C. Loewen. (2014) Genome sequence of Bacillus pumilus MTCC B6033. genomeA 2: e00327-14. View PDF

157. P. Vidossich, P. C. Loewen, X. Carpena, G. Fiorin, I. Fita, and C. Rovira. (2014) Binding of the anti-tubercular pro-drug isoniazid in the heme access channel of catalase-peroxidase (KatG). A combined structural and metadynamics investigation. J. Phys. Chem. B 118: 2924-2931. View PDF

156. M. M. S. Ismaiel, Y. M. El-Ayouty, P. C. Loewen, M. D. Piercey-Normore. (2014) Characterization of the iron-containing superoxide dismutase and its response to stress in cyanobacterium Spirulina (Arthrospira) platensis. J. Appl. Phycology DOI 10.1007/s10811-013-0233-y. View PDF

155. C. L. Berry, M. Nandi, J. Manuel, A. K. C. Brassinga, W. G. D. Fernando, P. C. Loewen and T. R. de Kievit. (2014) Characterization of the Pseudomonas sp. DF41 quorum sensing locus and its role in fungal antagonism. Biol. Control 69: 82-89. View PDF

2013

154. A. Ivancich, L. J. Donald, J. Villanueva, B. Wiseman, I. Fita, and P. C. Loewen. (2013) Spectroscopic and kinetic investigation of the reactions of peroxyacetic acid with Burkholderia pseudomallei catalase-peroxidase, KatG. Biochemistry 52: 7271-7282. View PDF

153. D. Aparicio, R. Perez-Luque, X. Carpena, M. Diaz, J. C. Ferrer, P. C. Loewen and I. Fita. (2013) Structural asymmetry and disulphide bridges amoung subunits modulate the activity of human malonyl-CoA decarboxylase. J. Biol. Chem. 288: 11907-11919. View PDF

152. P. C. Loewen, A. L. Didychuk, J. Switala, R. Perez-Luque, I. Fita and M. C. Loewen. (2013) Structure of Pisum sativum rubisco with bound ribulose-1,5-bisphosphate. Acta. Crystallog. F69: 10-14. View PDF

2012

151. D. A. Alarcon, M. Nandi, X. Carpena, I. Fita and P. C. Loewen. (2012) Structure of glycerol-3-phosphate dehydrogenase, GPD1, from Saccharomyces cerevisiae at 2.45 Å resolution. Acta. Crystallog. F68 :1279-1283. View PDF

150. M. Zamocky, Q. Garcia-Fernández, B. Gasselhuber, C. Jakopitsch, P. G. Furtmüller, P. C. Loewen, I. Fita, C. Obinger and X. Carpena. (2012) High conformation stability of secreted eukaryotic catalase-peroxidases – answers from the first crystal and unfolding studies. J. Biol. Chem. 287: 32254-32262. View PDF

149. V. Jha, P. Chelikani, X. Carpena, I. Fita and P. C. Loewen. (2012) Influence of main channel structure on H2O2 access to the heme cavity of catalase KatE of Escherichia coli. Arch. Biochem. Biophys. 526: 54-59. View PDF

148. C. L. Berry, A. K. C. Brassinga, L. J. Donald, W.G. D. Fernando, P. C. Loewen, and T. R. de Kievit. (2012) Investigation of the structure and biological activity of a novel lipopeptide essential for Pseudomonas sp. DF41 biocontrol of Sclerotinia sclerotiorum. Can. J. Microbiol. 58: 1027-1034. View PDF

147. A. Diaz, P. C. Loewen, I. Fita and X. Carpena. (2012) Thirty years of heme catalase structural biology. Arch. Biochem. Biophys 525: 102-110 View PDF

146. V. Jha, L. J. Donald and P. C. Loewen. (2012) Mutation of Phe413 to Tyr in catalase KatE from Escherichia coli leads to side chain damage and main chain cleavage. Arch. Biochem. Biophys 525: 207-214 (2012). View PDF

145. A. Ivancich and P. C. Loewen. (2012) Electron transfer in catalases and catalase-peroxidases. In Encyclopedia of Biophysics. ed. G. C. K. Roberts Springer-Verlag, Vol. 2, pp 611-614.

144. M. Hafez, M. Iranpour, S.-T. Mullineux, J. Sethuraman, K. Wosnitza, P. Lehn, J. Kroeker, P. C. Loewen, J. Reid, and G. Hausner. (2012) Group I intron-like elements within the SSU rDNA gene in species of Ceratocystiopsis and related taxa. Fungal Biol. 116:98-111. View PDF

2011

143. V. Jha, S. Louis, P. Chelikani, X. Carpena, L. J. Donald, I. Fita and P. C. Loewen. (2011) Modulation of heme orientation and binding by a single residue in catalase HPII of E. coli. Biochemistry 50: 2101-2110. View PDF

142. P. Vidossich, X. Carpena, P. C. Loewen, I. Fita and C. Rovira. (2011) Oxygen binding to catalase-peroxidase. J. Phys. Chem. Let. 2: 196-200. View PDF

2010

141. J. Reid, M. Iranpour, S. M. Rudski, P. C. Loewen and G. Hausner. (2010) A new conifer-inhabiting species of Ceratocystis from Norway. Botany 88: 971-983. View PDF

140. C. Berry, W. G. D. Fernando, P. C. Loewen, and T. R. de Kievit. (2010) Lipopeptides are essential for Pseudomonas sp. DF41 biocontrol of Sclerotinia sclerotiorum. Biological Control 55: 211-218. View PDF

139. B. Wiseman, X. Carpena, M. Feliz, L. J. Donald, M. Pons, I. Fita and P. C. Loewen. (2010) Isonicotinic acid hydrazide (INH) conversion to isonicotinyl-NAD by catalase-peroxidases. J. Biol. Chem. 285: 26662-26673. View PDF

138. P. Vidossich, M. Alfonso-Prieto, X. Carpena, I. Fita, P. C. Loewen and C. Rovira (2010) The dynamic role of distal side residues in heme hydroperoxidase catalysis. Interplay between X-ray crystallography and ab initio MD simulations. Arch. Biochem. Biophys. 500: 37-44. View PDF

2009

137. J. Colin, B. Wiseman, J. Switala, P. C. Loewen and A. Ivancich. (2009) Distinct role of specific tryptophans in facilitating electron transfer or as [Fe(IV)=O Trpo] intermediates in the peroxidase reaction of Burkholderia pseudomallei catalase-peroxidase: a multifrequency EPR spectroscopy investigation. J. Am. Chem. Soc. 131:8557-8563 View PDF

136. B. Wiseman, J. Colin, A. T. Smith, A. Ivancich and P. C. Loewen. (2009) Mechanistic insight into the initiation step of the reaction of Burkholderia pseudomallei catalatse-peroxidase with peroxyacetic acid. J. Biol. Inorg. Chem. 14: 801-811 View PDF

135. L. J. Donald, V. M. Collado, J. J. Galka, J. D. O’Neil, H. W. Duckworth, P. C. Loewen and K. G. Standing. (2009) Urea as a protein destabilizing agent in electrospray ionization. Rapid Commun. in Mass Spectrom. 23: 788-792 View PDF

2008

134. M. Alfonso-Prieto, P. Vidossich, A. Rodríguez-Fortea, X. Carpena, I. Fita, P. C. Loewen and Carme Rovira. (2008) Electronic state of the molecular oxygen released in the catalase reaction. J. Phys. Chem. A 112: 12842-12848. View PDF

133. A. J. Fielding, R. Singh, B. Boscolo, P. C. Loewen, E. M. Ghibaudi, and A. Ivancich. (2008) Intramolecular electron transfer vs. substrate oxidation in lactoperoxidase: investigation of the radical intermediates by stopped-flow absorption spectrophotometry and (9-285 GHz) EPR spectroscopy. Biochemistry 47: 9781-9792 View PDF

132. R. Singh, B. Wiseman, T. Deemagarn, V. Jha, J. Switala and P. C. Loewen. (2008) Comparative study of catalase-peroxidases (KatGs). Arch. Biochem. Biophys. 471: 207-214. View PDF

131. J. Richardson, X. Carpena, J. Switala, P. C. Loewen and I Oresnik. (2008) RhaU of Rhizobium leguminosarum is a rhamnose mutarotase. J. Bacteriol. 190: 2903-2910. View PDF

130. G. Hausner, J. Reid, G. G. Eyjolfsdottir, M. Iranpour and P. C. Loewen (2008) Basidiopycnides albertensis gen. et spec. nov., a new anamporphic fungus whith phylogenetic affinities in the Atractiellales (Basidiomycota). Mycotaxon. 103: 279-297. View PDF

2007

129. R. Singh, J. Switala, P. C. Loewen and A. Ivancich. (2007) Two [Fe(IV)=O Trp·] intermediates in M. tuberculosis catalase-peroxidase discriminated by multifrequency (9-285 GHz) EPR spectroscopy: reactivity towards isoniazid. J. Am. Chem. Soc. 129: 15954-15963. View PDF

128. P. Vidossich, M. Alfonso-Prieto, X. Carpena, P. C. Loewen, I. Fita and C. Rovera. (2007) Versatility of the electronic structure of compound I in catalase-peroxidases (KatGs). J. Am. Chem. Soc. 129: 13426-13446. View PDF

127. G. R. Golding, C. A. Kelly, R. Sparling, P. C. Loewen, and T. Barclay (2007) Evaluation of mercury toxicity as a predictor of mercury bioavailability. Environ. Sci. Tech41: 5685-5692. View PDF

126. M. Alfonso-Prieto, A. Borovik, X. Carpena, G. Murshudov, W. Melik-Adamyan, I. Fita, C. Rovira and P. C. Loewen. 2007. The structures and electronic configuration of compound I intermediates of Helicobacter pylori and Penicillium vitale catalases determined by X-Ray crystallography and QM/MM DFT calculations. J. Am. Chem. Soc.> 129: 4193-4205. View PDF

125. C. Jakopitsch, J. Vlasits, B. Wiseman, P. C. Loewen and C. Obinger. (2007) Redox intermediates in the catalase cycle of catalase-peroxidases from Synechocystis PCC 6803, Burkholderia pseudomallei, and Mycobacterium tuberculosis. Biochemistry 46: 1183-1193. View PDF

124. T. Deemagarn, B. Wiseman, X. Carpena, A. Ivancich, I. Fita and P. C. Loewen (2007) Two alternative substrate paths for compound I formation and reduction in catalase-peroxidase KatG from Burkholderia pseudomallei. Proteins 66: 219-228. View PDF

2006

123. X. Carpena, B. Wiseman, T. Deemagarn, B. Herguedas, A. Ivancich, R. Singh, P. C. Loewen, and I. Fita. (2006) Roles for Arg426 and Trp111 in the modulation of NADH oxidase activity of the catalase-peroxidase KatG from Burkholderia pseudomallei inferred from pH-induced structural changes. Biochemistry 45: 5171-5179. View PDF

122. C. Rovira, M. Alfonso, X. Biarnés, X. Carpena, I. Fita, and P. C. Loewen. (2006) A first principles study of the binding of formic acid in catalase complementing high resolution X-ray structures. Chem. Phys. 323: 129-137. View PDF

121. M. Miller-Williams, P. C. Loewen and I. J. Oresnik. (2006) Isolation of salt sensitive mutants of Sinorhizobium meliloti strain Rm1021 Microbiology 152: 2049-2059. View PDF

120. K. Choudhary, V. L. Spicer, L. J. Donald, H. W. Duckworth, W. Ens, P. C. Loewen, and K. G. Standing. (2006) A method for estimating the isotopic distributions of metabolically labeled proteins by MALDI-TOFMS: application to NMR samples. Anal. Chem. 78: 5419-5423. View PDF

2005

119. R. Habibian, J. Dzioba, J. Barrett, M. Y. Galperin, P. C. Loewen and P. Dibrov. (2005). Functional analysis of conserved polar residues in VcNhaD, Na+/H+ antiporter of Vibrio cholerae. J. Biol. Chem. 280: 39637-39643. View PDF

118. X. Carpena, B. Wiseman, T. Deemagarn, R. Singh, J. Switala, A. Ivancich, I. Fita and P.C. Loewen (2005) A molecular switch and electronic circuit modulate activity in catalase-peroxidases. EMBO Reports 6: 1156-1162. View PDF

117. G. Hausner, M. Iranpour, J.-J. Kim, C. Breuil, C, N. Davis, E. A. Gibb, J. Reid, J., P. C. Loewen, and A. A. Hopkin. (2005). Fungi vectored by the introduced bark beetle Tomicus piniperda in Ontario, Canada and comments on the taxonomy of Leptographium lundbergii, L. terebrantis, L. truncatum and L. wingfieldii. Can. J. Bot. 83: 1222-1237. View PDF

116. P.Chelikani, X. Carpena, R. Perez-Luque, L. J. Donald, H. W. Duckworth, J. Switala, I. Fita and P. C. Loewen. (2005) Characterization of a large subunit catalase truncated by proteolytic cleavage. Biochemistry 44: 5597-5605. View PDF

115. T. Deemagarn, X. Carpena, R. Singh, B. Wiseman, I. Fita and P. C. Loewen. (2005) Structural characterization of the Ser324Thr variant of the catalase-peroxidase (KatG) from Burkholderia pseudomallei. J. Mol. Biol. 345: 21-28. View PDF

2004

114. X. Carpena, W. Melik-Adamyan, P. C. Loewen, and I. Fita. 2004. Crystal structure of the C-terminal domain from the catalase-peroxidase KatG of Escherichia coli. Acta Cryst. D60: 1824-1832. View PDF

113. S. H. Cho, P. C. Loewen, and R. R. Marquardt 2004. A plasmid DNA encoding chicken Interleukin-6 and Escherichia coli K88 fimbrial protein FaeG stimulates the production of anti-K88 fimbrial antibodies in chickens Poultry Sci. 83: 1973-1978. View PDF

112. R. Singh, B. Wiseman, T. Deemagarn, L. J. Donald, H. W. Duckworth, X.Carpena, I. Fita, and P. C. Loewen 2004. Catalase-peroxidases (KatG) exhibit NADH oxidase activity. J. Biol. Chem. 279: 43098-43106. View PDF

111. P. C. Loewen, X. Carpena, R. Perez-Luque, C. Rovira, A. Ivancich, R. Perez-Luque, R. Haas, S. Odenbreit, P. Nicholls, and I. Fita. 2004. Structure of Helicobacter pylori catalase, with and without formic acid bound, at 1.6 Å resolution. Biochemistry 43: 3089-3103. View PDF

110. P. Chelikani, I. Fita and P. C. Loewen 2004. Diversity of structures and properties among catalases. Cell Molec. Life Sci. 61: 192-208. View PDF

2003

109. L. J.Donald, O. V. Krokhin, H. W. Duckworth, B.Wiseman, T. Deemagarn, R.Singh, J. Switala, X. Carpena, I. Fita and P. C. Loewen (2003) Characterization of the catalase-peroxidase KatG from Burkholderia pseudomallei by mass spectrometry. J. Biol. Chem. 278: 35687-35692. View PDF

108. P. Chelikani, X. Carpena, I. Fita and P. C. Loewen 2003. An electrical potential in the access channel of catalases enhances catalysis. J. Biol. Chem.278: 31290-31296. View PDF

107. P. Chelikani, L. J. Donald, H. W. Duckworth and P. C. Loewen 2003. Hydroperoxidase II of Escherichia coli exhibits enhanced resistance to proteolytic cleavage compared to other catalases. Biochemistry 42: 5729-5735. View PDF

106. M. G. Klotz and P. C. Loewen (2003) The molecular evolution of catalatic hydroperoxidases: Evidence for multiple lateral transfer of genes between prokaryota and from bacteria into eukaryota. Molec. Biol. Evol. 20: 1098-1112. View PDF

105. X. Carpena, S. Loprasert, S. Mongkolsuk, J. Switala, P. C. Loewen and I. Fita. 2003. Catalase-peroxidase KatG of Burkholderia pseudomallei at 1.7 Å resolution. J. Mol. Biol. 327: 475-489. View PDF

104. X. Carpena, M. Soriano, M. G. Klotz, H. W. Duckworth, L. J. Donald, I. Fita and P. C. Loewen. 2003. Structure of the clade 1 catalase, CatF from Pseudomonas syringae at 1.7 Å resolution. Proteins50: 423-436. View PDF

103. N. Chauvatcharin, P. Vattanaviboon, J. Switala, P. C. Loewen, and S. Mongkolsuk 2003. Cloning and characterization of katA, encoding the major monofunctional catalase from Xanthomonas campestris pv. phaseoli and characterization of the encoded catalase KatA. Curr. Microbiol. 46: 83-87. View PDF

2002

102. X. Carpena, J. Switala, S. Loprasert, S. Mongkolsuk, I. Fita and P. C. Loewen. 2002. Crystallization and preliminary X-ray analysis of the catalase-peroxidase KatG from Burkholderia pseudomallei. Acta Cryst.D58: 2184-2186. View PDF

101. E. Ostroumov, J. Dzioba, P. C. Loewen and P. Dibrov 2002. Asp344 and Thr345 are critical for cation exchange mediated by NhaD, Na+/H+ antiporter of Vibrio cholerae. Biochim. Biophys. Acta. 1564: 99-106. View PDF

100. G. R. Golding, C. A. Kelly, R.Sparling, P. C. Loewen, J. W. M. Rudd, and T. Barkay. 2002. Evidence for facilitated uptake of Hg(II) by Vibrio anguillarum and Escherichia coli under anaerobic and aerobic conditions. Limnol. Oceanog.47: 967-975. View PDF

99. J. Switala and P. C. Loewen. 2002 Diversity of properties among catalases. Arch. Biochem. Biophys. 401:145-154. View PDF

98. X. Carpena, A. Guarné, J. C. Ferrer, P. M. Alzari, I. Fita, and P. C. Loewen. 2002 Crystallization and preliminary X-ray analysis of the hydroperoxidase I C-terminal domain from Eschericia coli. Acta Cryst.D58: 853-855. View PDF

2001

97. X. Carpena, R. Perez, W. F. Ochoa, N. Verdaguer, M. Klotz, J. Switala, W. Melik-Adamyan, I. Fita, and P. C. Loewen. 2001. Crystallisation and preliminary X-ray analysis of Clade I catalases from Pseudomonas syringae and Listeria seeligeri. Acta Cryst. D57: 1184-1186. View PDF

96. G. Regelsberger, C. Jakopitsch, F. Rüker, J. Switala, P. C. Loewen, and C. Obinger. 2001. The role of distal tryptophan in the bifunctional activity of catalase-peroxidases. Biochem. Soc. Trans. 29: 99-105. View PDF

95. W. Melik-Adamyan, J. Bravo, X. Carpena, J. Switala, M. J. Maté, I. Fita and P. C. Loewen. 2001. Substrate flow in catalases deduced from the crystal structures of active site variants of HPII from Escherichia coli. Proteins 44: 270-281. View PDF

94. L. Powers, A. Hillar and P. C. Loewen. 2001. Active site structure of the catalase-peroxidases from Mycobacterium tuberculosis and Escherichia coli by extended X-ray absorption fine structure analysis (EXAFS) Biochim. Biophys. Acta 1546: 44-54. View PDF

93. P. Nicholls, I. Fita and P. C. Loewen. 2001. Enzymology and structure of catalases. Adv. Inorg. Chem. 51: 51-106. View PDF

92. M. J. Mate, G. Murshudov, J. Bravo, W. Melik-Adamyan, P. C. Loewen and I. Fita. 2001. Heme catalases. In: Handbook of Metalloproteins pp 486-502, J. Wiley & Sons, New York, NY View PDF

2000

91. P. C. Loewen, M. G. Klotz, and D. J. Hassett. 2000. Catalase – an ‘old’ enzyme that continues to surprise us. ASM News 66: 76-82. View PDF

90. A. Hillar, B. Peters, R. Pauls, A. Loboda, H. Zhang, A. G. Mauk, and P. C. Loewen. 2000. Modulation of the activities of catalase-peroxidase HPI of Escherichia coli by site-directed mutagenesis. Biochemistry 39: 5868-5875. View PDF

1999

89. M. J. Mate, M. S. Sevinc, B. Hu, J. Bujons, J. Bravo, J. Switala, W. Ens, P. C. Loewen, and I. Fita. 1999. Mutants that alter the covalent structure of catalase HPII from Escherichia coli. J. Biol. Chem. 274: 27717-27725. View PDF

88. P. C. Loewen.1999. Catalase. In: The Encyclopedia of Molecular Biology ed. T. Creighton, pp 351-353, J. Wiley & Sons, New York, NY View PDF

87. J. Switala, J. O’Neil, and P. C. Loewen. 1999. Catalase HPII from Escherichia coli exhibits enhanced resistance to denaturation. Biochemistry 38: 3895-3901. View PDF

86. A. Hillar, L. Van Caeseele and P. C. Loewen. 1999. Intracellular location of catalase-peroxidase HPI of E. coli. FEMS Microbiol. Lett. 170: 307-312. View PDF

85. M. S. Sevinc, M. J. Mate, J. Switala, I. Fita, and P. C. Loewen. 1999. Role of the lateral channel in catalase HPII of Escherichia coli. Protein Sci. 8: 490-498. View PDF

84. J. Bravo, M. J. Mate, T. Schneider, J. Switala, K. Wilson, P. C. Loewen, and I. Fita. 1999. Structure of catalase HPII from Escherichia coli at 1.9 Å resolution. Proteins 34: 155-166. View PDF

1998

83. P. C. Loewen, B. Hu, J. Strutinsky and R. Sparling. 1998. Regulation in the rpoS regulon of Escherichia coli. Can. J. Microbiol. 44: 707-717. View PDF

82. M. S. Sevinc, J. Switala, J. Bravo, I. Fita, and P.C. Loewen. 1998. Truncation and heme pocket mutations reduce the accumulation of functional catalase HPII of Escherichia coli. Prot. Eng. 11: 549-555. View PDF

81. M. Maj, P. C. Loewen and P. Nicholls. 1998. E. coli HPII catalase interaction with high spin ligands: formate and fluoride as active site probes. Biochim. Biophys. Acta 1384: 209-222. View PDF

1997

80. K. Tanaka, K. Handel, P. C. Loewen and H. Takahashi. 1997. Identification and analysis of the RpoS-dependent promoter of katE, encoding catalase HPII in Escherichia coli. Biochim. Biophys. Acta 1352: 161-166. View PDF

79. C. Obinger, M. Maj, P. Nicholls and P. C. Loewen. 1997. Activity, peroxide compound formation and heme d synthesis in E. coli HPII catalase. Arch. Biochem. Biophys. 342: 58-67. View PDF

78. J. Bravo, I. Fita, J. C. Ferrer, W. Ens, A. Hillar, J. Switala and P. C. Loewen. 1997. Identification of a novel bond between a histidine and the essential tyrosine in catalase HPII of Escherichia coli. Protein Science 6: 1016-1023. View PDF

77. M. G. Klotz, G. R. Klassen and P. C. Loewen. 1997. Phylogenetic relationaships among prokaryotic and eukaryotic catalases. Molec. Biol. Evol. 14: 951-958. View PDF

76. P. C. Loewen 1997. Bacterial catalases. In: Oxidative Stress and the Molecular Biology of Antioxidant Defenses. pp.273-308. Cold Spring Harbor Laboratory Press, Cold Spring Harbor NY View PDF

1996

75. M. Maj, P. Nicholls, C. Obinger, A. Hillar and P.C. Loewen. 1996. Reaction of E. coli catalase HPII with cyanide as ligand and as inhibitor. Biochim. Biophys. Acta1298: 241-249. View PDF

74. P. C. Loewen. 1996. Probing the structure of HPII of Escherichia coli – a review. Gene 179: 39-44. View PDF

73. G. N. Murshudov, A. I. Grebenko, V. Barynin, Z. Dauter, K. S. Wilson, B. K. Vainshtein, W. Melik-Adamyan, J. Bravo, J. M. Ferran, J. C. Ferrer, J. Switala, P. C. Loewen, and I. Fita. 1996. Structure of heme d of Penicillium vitale and Escherichia coli catalases. J. Biol. Chem. 271: 8863-8868. View PDF

1995

72. P. C. Loewen and J. Switala. 1995. Template structure can increase the error frequency of the DNA polymerase from Thermus aquaticus. Gene 164: 59-63. View PDF

71. A. Hillar and P. C. Loewen. 1995. Comparison of isoniazid oxidation catalyzed by bacterial catalase-peroxidases and horse radish peroxidase. Arch. Biochem. Biophys. 323: 438-446. View PDF

70. M. S. Sevinc, W. Enns and P. C. Loewen. 1995. The cysteines of catalase HPII of Escherichia coli, including Cys438 which is blocked, do not have a catalytic role. Eur. J. Biochem. 230: 127-132. View PDF

69. J. Bravo, N. Verdaguer, J. Tormo, C. Betzel, J. Switala, P. C. Loewen and I. Fita 1995. Crystal structure of catalase HPII from Escherichia coli. Structure 3: 491-502. View PDF

68. N. A. Buchmeier, S. J. Libby, Y. Xu, P. C. Loewen, J. Switala, D. G. Guiney and F. C. Fang. 1995. DNA repair is more important than catalase for Salmonella virulence in mice. J. Clin. Invest. 95: 1047-1053. View PDF

1994

67. P. C. Loewen and R. Hengge-Aronis. 1994. The role of the sigma factor sigma-S (KatF) in bacterial global regulation. Annu. Rev. Microbiol. 48: 53-80. View PDF

66. A. Hillar, P. Nicholls, J. Switala and P. C. Loewen. 1994. NADPH binding and control of catalase compound II formation: comparison of bovine, yeast and Escherichia coli enzymes. Biochem. J. 300: 531-539. View PDF

65. F. F. Davidson, P. C. Loewen and H. G. Khorana. 1994. Structure and function in rhodopsin: replacement by alanine of cysteine residues 110 and 187, components of a conserved disulfide bond in rhodopsin, affects the light-activated metarhodopsin II state. Proc. Natl. Acad. Sci USA 91: 4029-4033. View PDF

64. M. R. Volkert, P. C. Loewen, J. Switala, D. Crowley and M. Conley. 1994. The delta(argF-lacZ)205(U169) deletion greatly enhances resistance to hydrogen peroxide in stationary-phase Escherichia coli. J. Bacteriol.176: 1297-1302. View PDF

1993

63. P. C. Loewen, J. Switala, I. von Ossowski, A. Hillar, A. Christie, B. Tattrie and P. Nicholls. 1993. Catalase HPII of Escherichia coli catalyzes the conversion of protoheme to cis-heme d. Biochemistry 32: 10159-10164. View PDF

62. I. von Ossowski, G. Hausner, and P.C. Loewen. 1993. Molecular evolutionary analysis based on the amino acid sequence of catalase. J. Mol. Evol.37: 71-76. View PDF

61. P.C. Loewen, I. von Ossowski, J. Switala and M.R. Mulvey. 1993. KatF (sigma-S) synthesis in Escherichia coli is subject to post-transcriptional regulation. J. Bacteriol.> 175: 2150-2153. View PDF

1992

60. F.C. Fang, S.J. Libby, N.A. Buchmeier, P.C. Loewen, J. Switala, J. Harwood, and D.G. Gurney. 1992. The alternative sigma factor KatF regulates Salmonella virulence. Proc. Natl. Acad. Sci. USA 89: 11978-11982. View PDF

59. Q. Pang, R. Timkovich, P.C. Loewen and J. Peterson. 1992. Identification of heme macrocycle type by near-infrared magnetic circular dichroism spectroscopy at cryogenic temperatures. FEBS Lett. 309: 157-160. View PDF

58. P.C. Loewen. 1992. Regulation of bacterial catalase synthesis. In: Molecular Biology of Free Radical Scavenging Systems>. pp. 77-115. Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. View PDF

1991

57. J.H. Dawson, A.M. Bacete, A.M. Huff, S. Kadkhodayan, C.M. Zeitter, M. Sono, C.K. Chang and P.C. Loewen. 1991. The active site structure of E. coli HPII catalase. Evidence favoring coordination of a tyrosinate proximal legand to the chlorin iron. FEBS Lett.> 295: 123-126. View PDF

56. I. von Ossowski, M.R. Mulvey, P.A. Leco, A. Borys and P.C. Loewen 1991. Nucleotide sequence of katE of Escherichia coli encoding catalase HPII. J. Bacteriol. 173: 514-520. View PDF

1990

55. M.R. Mulvey, J. Switala, A. Borys and P.C. Loewen 1990. Regulation of transcription of katE and katF in Escherichia coli. J. Bacteriol. 172: 6713-6720. View PDF

54. P.C. Loewen and G.V. Stauffer. 1990. Nucleotide sequence of katG of Salmonella typhimurium LT2 and characterization of its product, hydroperoxidase I. Molec. Gen. Genet. 224: 147-151. View PDF

53. J. Switala, B.L. Triggs-Raine and P.C. Loewen 1990. Homology among bacterial catalase genes. >Canad. J. Microbiol. 36: 728-731. View PDF

52. P.C. Loewen, J. Switala, M. Smolenski and B.L. Triggs-Raine 1990. Molecular characterization of three mutations in katG, affecting the activity of hydroperoxidase I of Escherichia coli. Biochem. Cell Biol. 68: 1037-1044. View PDF

51. J. Tormo, I. Fita, J. Switala and P.C. Loewen 1990. Crystallization and preliminary x-ray diffraction analysis of catalase HPII from Escherichia coli. J. Mol. Biol. 213: 219-220. View PDF

1989

50. M.R. Mulvey and P.C. Loewen. 1989. Nucleotide sequence of katF suggests KatF protein is a novel sigma transcription factor. Nucl. Acids Res.> 17: 9979-9991. View PDF

49. J.T. Chiu, P.C. Loewen, J. Switala, R.B. Gennis & R. Timkovich. 1989. Proposed structure for the prosthetic group of the catalase HPII from Escherichia coli. J. Am. Chem. Soc. 111: 7046-7050. View PDF

48. P.C. Loewen. 1989. Genetic mapping of katB, a locus that affects catalase 2 levels in Bacillus subtilis. Can. J. Microbiol. 35: 807-810. View PDF

1988

47. M.R. Mulvey, P.A. Sorby, B.L. Triggs-Raine and P.C. Loewen. 1988. Cloning and physical characterization of katE and katF, required for catalase HPII expression in E. coli. Gene 73: 337-345. View PDF

46. B.L. Triggs-Raine, B.W. Doble, M.R. Mulvey, P.A. Sorby and P.C. Loewen. 1988. Nucleotide sequence of katG encoding catalase HPI of Escherichia coli. J. Bacteriol. 170: 4415-4419. View PDF

45. P.C. Loewen and J. Switala. 1988. Purification and characterization of spore-specific catalase-2 from Bacillus subtilis. Biochem. Cell. Biol.66: 707-714. View PDF

44. H.E. Richter, J. Switala and P.C. Loewen 1988. Effect of ascorbate on oxygen uptake and growth of Escherichia coli B. >Can. J. Microbiol. 34: 822-824. View PDF

1987

43. P.C. Loewen and J. Switala 1987. Genetic mapping of katA, a locus that affects the synthesis of catalase-1 in Bacillus subtilis. J. Bacteriol. 169: 5848-5851. View PDF

42. P.C. Loewen and J. Switala 1987. Purification of catalase-1 from Bacillus subtilis. Biochem. Cell Biol. 65: 939-947. View PDF

41. P.C. Loewen and J. Switala 1987. Multiple catalases in Bacillus subtilis. J. Bacteriol. 169: 3601-3607. View PDF

40. B.L. Triggs-Raine and P.C. Loewen 1987. Physical characterization of katG, encoding catalase HPI of Escherichia coli. Gene 52: 121-128. View PDF

1986

39. P.C. Loewen and J. Switala 1986. Purification and characterization of catalase HPII from Escherichia coli K12. Can. J. Biochem. Cell Biol. 64: 638-646. View PDF

1985

38. P.C. Loewen, J. Switala and B.L. Triggs-Raine 1985. Catalases HPI and HPII in Escherichia coli are induced independently. Arch. Biochem. Biophys. 243: 144-149. View PDF

37. P.C. Loewen, B.L. Triggs, C.S. George and B.E. Hrabarchuk 1985. Genetic mapping of katG, a locus that affects the synthesis of the bifunctional catalase-peroxidase HPI in Escherichia coli. J. Bacteriol. 162: 661-667. View PDF

36. F.C. Wong, J.G. Spearman, M.A. Smolenski and P.C. Loewen 1985. Equine parvovirus: Initial isolation and partial characterization. Can. J. Comp. Med. 49: 50-54. View PDF

35. P.C. Loewen 1985. Detection of p-aminobenzoylpoly(gamma-glutamates) using fluorescamine. Methods in Enzymology 122: 330-333. View PDF

1984

34. P.C. Loewen and B.L. Triggs 1984. Genetic mapping of katF, a locus that with katE affects the synthesis of a second catalase species in Escherichia coli. J. Bacteriol. 160: 668-675. View PDF

33. P.C. Loewen 1984. Isolation of catalase-deficient Escherichia coli mutants and genetic mapping of katE, a locus that affects catalase activity. J. Bacteriol. 157: 622-626. View PDF

1983

32. P.C. Loewen, B.L. Triggs, G.R. Klassen and J.H. Weiner 1983. Identification and physical characterisation of a ColEl hybrid plasmid containing a catalase gene of Escherichia coli. Can. J. Biochem. 61: 1315-1321. View PDF

31. P.C. Loewen and H.E. Richter 1983. Inhibition of sugar uptake by ascorbic acid in Escherichia coli. Arch. Biochem. Biophys. 226: 657-665. View PDF

30. W.J.P. Blonski, F.E. Hruska, K.L. Sadana and P.C. Loewen 1983. Conformational studies of ribo-, 2′-deoxyribo- and arabinonucleotides by carbon 13 NMR. <Biopolymers 22: 605-616. View PDF

1982

29. H.E. Richter and P.C. Loewen 1982. Rapid inactivation of bacteriophage T7 by ascorbic acid is repairable. Biochem. Biophys. Acta 697: 25-30. View PDF

28. H.E. Richter and P.C. Loewen 1982. Catalase synthesis in Escherichia coli is not controlled by catabolite repression. Arch. Biochem. Biophys.215: 72-77. View PDF

1981

27. K.L. Sadana, F.E. Hruska and P.C. Loewen 1981. A simplified strategy for the synthesis of dideoxyribonucleotide blocks. Tetrahedron Letters< 22: 3367-3370. View PDF

26. R.A.H. Furness and P.C. Loewen 1981. Detection of p-aminobenzoyl(gamma- glutamates) using fluorescamine. Anal. Biochem. 117: 126-135. View PDF

25. H.E. Richter and P.C. Loewen 1981. Induction of catalase in Escherichia coli by ascorbic acid involves hydrogen peroxide. Biochem. Biophys. Res. Comm. 100: 1039-1046. View PDF

24. W.P. Niemczura, F.E. Hruska, K.L. Sadana and P.C. Loewen 1981. Proton magnetic resonance study of nucleosides, nucleotides and dideoxynucleoside monophosphates containing a syn pyrimidine base. Biopolymers 20: 1671-1690. View PDF

23. P.C. Loewen 1981. Effect of glutathione deficiency on the pool of CoA-glutathione mixed disulfide in Escherichia coli. Can. J. Biochem. 59: 379-382. View PDF

1979

22. W.C.H. Bees and P.C. Loewen 1979. Partial characterization of the mode of inhibition of E. coli RNA polymerase by the mixed disulfide, CoASSG. Can. J. Biochem. 57: 336-345. View PDF

21. P.C. Loewen 1979. Levels of glutathione in E. coli. Can. J. Biochem. 57: 107-111. View PDF

1978

20. K.L. Sadana and P.C. Loewen 1978. A rapid and efficient synthesis of ribonucleotides. Tetrahedron Letters 5095-5098. View PDF

19. P.C. Loewen 1978. Levels of coenzyme A-glutathione mixed disulfide in Escherichia coli. Can. J. Biochem. 56: 753-759. View PDF

18. D.R. McNaughton, G.R. Klassen, P.C. Loewen and H.B. LéJohn 1978. Recharacterization of fungal dinucleoside polyphosphate (HS3). Can. J. Biochem.56: 217-226. View PDF

17. J. Peeling, F.E. Hruska and P.C. Loewen 1978. Ribo-, 2′-deoxyribo- hybrid dinuclesoide monophosphates. Proton, magnetic resonance studies of 3′, 5′- and 2′,5′-uridylyl-2′-deoxythymidine. Can. J. Chem.> 56: 522-529. View PDF

1977

16. P.C. Loewen l977. Identification of a coenzyme A-glutathione disulfide (DSI), a modified coenzyme A disulfide (DSII) and a NADPH-dependent coenzyme A-glutathione disulfide reductase in E. coli. Can. J. Biochem. 55: 1019-1027. View PDF

1976

15. P.C. Loewen 1976. Partial characterization of an endonuclease activity which appears in nuclease free T4 polynucleotide kinase. Nucl. Acids Res. 3: 3133-3141. View PDF

14. G.R. Klassen, R.A. Furness and P.C. Loewen 1976. Inhibition of E. coli DNA dependent RNA polymerase by novel nucleotides DSI and DSII. Biochem. Biophys. Res. Comm. 72: 1056-1062. View PDF

13. P.C. Loewen 1976. Novel nucleotides from E. coli isolated and partially characterized. Biochem. Biophys. Res. Comm. 70: 1210-1218. View PDF

12. R. Kleppe, T. Sekiya, P.C. Loewen, K. Kleppe, A.L. Agarwal, H. Buchi, P. Besmer, M.H. Caruthers, P.J. Cashion, M. Fridkin, E. Jay, A. Kumar, R.C. Miller, K. Minamoto, A. Panet, U.L. RajBhandary, B. Ramamoorthy, N. Siderova, T. Takeya, J.H. van de Sande and H.G. Khorana 1976. Studies on Polynucleotides CXLI. Total synthesis of the structural gene for the precursor of a tyrosine suppressor transfer RNA from E. coli. Enzymatic joining to form the total DNA duplex. J. Biol. Chem. 251: 667-675. View PDF

11. P.C. Loewen, R.C. Miller, A. Panet, T. Sekiya and H.G. Khorana 1976.Studies on polynucleotides CXXXVIII. Total synthesis of the structural gene for the precursor of a tyrosine suppressor transfer RNA from E. coli. Enzymatic joining of the chemically synthesized segments to form DNA duplexes corresponding to the nucleotide sequences 23 to 60 and 23 to 66. J. Biol. Chem. 251: 642-650. View PDF

10. H.G. Khorana, K.L. Agarwal, P. Besmer, H. Buchi, M.H. Caruthers, P.J. Cashion, M. Fridkin, E. Jay, K. Kleppe, R. Kleppe, A. Kumar, P.C. Loewen, R.C. Miller, K. Minamoto, A. Panet, U.L. RajBhandary, B. Ramamoorthy, T. Sekiya, T. Takeya and J.H. van de Sande 1976. Studies on Polynucleotides CXXXI. Total synthesis of the structural gene for the precursor of a tyrosine suppressor transfer from E. coli. General introduction. J. Biol. Chem. 251: 565-570. View PDF

1974

9. P.C. Loewen 1974. Determination of the sequences of 18 nucleotides from the 5′-end of the 1-strand and 15 nucleotides from the 5′-end of the r-strand of T7 DNA. Nucleic Acids Research 2: 839-852. View PDF

8. P.C. Loewen, T. Sekiya and H.G. Khorana 1974. Studies on Polynucleotides CXXVI. The nucleotide sequence adjoining the CCA end of the E. coli tyrosine transfer RNA gene. >J. Biol. Chem. 249: 217-226. View PDF

1973

7. P.C. Loewen and H.G. Khorana 1973. Studies on Polynucleotides CXXII. Dodecanucleotide sequence adjoining the CCA end of the tyrosine transfer RNA gene. J. Biol. Chem. 248: 3489-3499. View PDF

6. A. Panet, J.H. van de Sande, P.C. Loewen, H.G. Khorana, A.J. Raae, J.L. Lillehaug and K. Kleppe 1973. Studies on Polynucleotides CXXIII. Physical characterisation and simultaneous purification of bacteriophage T4 induced polynucleotide kinase, polynucleotide ligase and DNA polymerase. Biochemistry 12: 5045-5050. View PDF

1972

5. H. van de Sande, P.C. Loewen and H.G. Khorana 1972. Studies on Polynucleotides CXVIII. A further study of ribonucleotide incorporation into DNA by DNA polymerase I of E. coli. J. Biol. Chem. 247: 6140-6148. View PDF

4. P.C. Loewen and R.K. Brown 1972. 2-Aryloxytetrahydrofurans. Their reductive cleavage by ether solutions of AlH2Cl and their cleavage and rearrangement by ether solutions of AlCl3. Can. J. Chem. 50: 3639-3647. View PDF

3. P.C. Loewen, L.P. Makubu and R.K. Brown 1972. The influence of the 2-alkoxy group and C-5 substituents on the direction of reductive cleavage of 2-alkoxytetrahydrofurans by AlH2Cl in ether solution. Can. J. Chem. 50: 1502-1512. View PDF

1969

2. P.C. Loewen, W.W. Zajac and R.K. Brown 1969. Hydrogenolysis of LiAlH4-AlCl3 of an ether solution of norcamphor isobutylene ketal. Can. J. Chem. 47: 4059-4067. View PDF

1965

1. T.L. Richards and P.C. Loewen 1965. A preliminary investigation of solar radiation over the Great Lakes as compared to adjacent land areas. Proc. Eighth Conf. on Great Lakes Research 13: 278-282. View PDF


Tetrameric catalase HPII of E. coli

Monomer of HPII before (top) and after (bottom) treatment with proteinase K (protease resistant core in red).




H. pylori catalase as a monomer (top), dimer (middle) and active tetramer (bottom) forms.