Isolation and characterization of a thermostable intracellular enzyme withperoxidase activity from Bacillus sphaericus

Apitz, A van Pee, KH

A. Apitz et Kh. Van Pee, Isolation and characterization of a thermostable intracellular enzyme withperoxidase activity from Bacillus sphaericus, ARCH MICROB, 175(6), 2001, pp. 405-412

34

INGLESE

Article

Microbiology

ARCHIVES OF MICROBIOLOGY

0302-8933 → ACNP

175

6

2001

405 - 412

ISI

0302-8933(200106)175:6<405:IACOAT>2.0.ZU;2-R

During a screening for bacteria producing enzymes with peroxidase activity, a Bacillus sphaericus strain was isolated. This strain was found to contai n an intracellular enzyme with peroxidase activity. The native enzyme had a molecular mass of above 300 kDa and precipitated at a salt concentration h igher than 0.1 M. Proteolytic digestion with trypsin reduced the molecular mass of the active enzyme to 13 kDa (dimer) or 26 kDa (tetramer) and increa sed its solubility, allowing purification to homogeneity. Spectroscopic inv estigations showed the enzyme to be a hemoenzyme containing heme c as the c ovalently bound prosthetic group. The enzyme was stable up to 90 degreesC a nd at alkaline conditions up to pH 11, with a pH optimum at pH 8.5. It coul d be visualized by activity staining after SDS-PAGE and showed activity wit h a number of typical substrates for peroxidases, e.g., 2,2 ' -azino-bi5(3- ethylbenz-thiazoline-6-sulfonic acid) diammonium salt, guaiacol and 2,4-dic hlorophenol; however the enzyme had no catalase and cytochrome c peroxidase activity.