Identification of two catalases in Azotobacter vinelandii: a KatG homologue and a novel bacterial cytochrome c catalase, CCCAv.

ABSTRACT: Azotobacter vinelandii produces two detectable catalases during growth on minimal medium. The heat-labile catalase expressed during exponential growth phase was identified as a KatG homologue by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using a mixed protein sample. The second catalase was heat resistant and had substantial residual activity after treatment at 90 degrees C. This enzyme was purified by anion-exchange and size exclusion chromatography and was found to exhibit strong absorption at 407 nm, which is often indicative of associated heme moieties. The purified protein was fragmented by proteinase K and identified by LC-MS/MS. Some identity was shared with the MauG/bacterial cytochrome c peroxidase (BCCP) protein family, but the enzyme exhibited a strong catalase ac

SUBMITTER: Sandercock JR 

PROVIDER: S-EPMC2223588 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature