[Metalloproteinase of Bacillus mesentericus, strain V-313]

Area of Science:

• Biochemistry
• Enzymology
• Microbial Biotechnology

Background:

• Metalloproteinases are crucial enzymes with diverse biological functions.
• Bacillus species are known producers of various extracellular enzymes, including proteases.
• Characterization of novel enzymes from microbial sources is essential for biotechnological applications.

Purpose of the Study:

• To isolate and characterize a homogeneous metalloproteinase from Bacillus mesentericus, strain B-313.
• To determine the enzyme's physicochemical properties, including molecular mass, N-terminal sequence, and optimal activity conditions.
• To investigate the enzyme's catalytic mechanism and substrate specificity.

Main Methods:

• Homogeneous metalloproteinase isolation using chromatography (bacitracin-silochrome) and gel filtration (Acrylex P-10, Sephadex G-75).
• Determination of molecular mass (41,000 Da) and N-terminal amino acid sequencing.
• Enzyme activity assays under varying pH and temperature conditions; inhibition studies with o-phenanthroline and EDTA.

Main Results:

• A homogeneous metalloproteinase was isolated with a 28% yield.
• The enzyme's N-terminal sequence is identical to that of Bacillus amyloliquefaciens metalloproteinase.
• Optimal activity observed at 55°C and pH 6.5-7.2; stable between pH 7.0-9.5 and below 45°C.
• Catalytic activity involves ionogenic groups with pKa 7.4 and 6.2, likely histidine and carboxyl groups.
• Hydrolyzes peptide bonds adjacent to hydrophobic amino acids, particularly leucine residues.

Conclusions:

• Bacillus mesentericus produces a metalloproteinase with characteristics similar to other known Bacillus metalloproteinases.
• The enzyme's stability and substrate specificity suggest potential applications in industrial processes.
• Further studies are warranted to explore the full biotechnological potential of this enzyme.