β-Lytic Protease of VKM B-2533.

Bacteriolytic enzymes are promising antimicrobial agents for developing new-generation drugs. Recently, we have isolated a β-lytic protease (BlpLc) from the culture liquid of VKM B-2533. This BlpLc possesses a valuable property, not described for β-lytic proteases (Blps) earlier, of hydrolyzing living cells of 55 MRSA clinical isolate. This work phylogenetically characterized the BlpLc and investigated its properties. Analysis revealed a variability of pre-/pro-parts of Blp precursors. The mature BlpLc is the closest to the earlier annotated but not isolated Blp from sp. Root690. The biochemical characterization found conditions for the BlpLc general bacteriolytic activity relative to autoclaved 209P cells to differ from that of earlier isolated Blp. Unexpected was the effect of serine (phenylmethylsulfonyl fluoride (PMSF)) and cysteine (p-chloromercuribenzoate (p-CMB)) protease inhibitors on BlpLc bacteriolytic and proteolytic activities. The specificity of BlpLc proteolytic action relative to hemoglobin, elastin, gelatin, collagen, azofibrin, myoglobin, ovalbumin, and ovamucoid was found. New types of peptide bonds-Gly-X, Ser-X, Lys-X, Ala-X, Val-X, Glu-X, and Phe-X-hydrolyzed by the enzyme in protein substrates were first revealed using MALDI-TOF. Turbidimetrically, the BlpLc was found to lyze living cells of 209P, B1819, and B1236, which is important for expanding the enzyme's applied properties.