Official Full Name
V8 Protease
Background
Protease S. aureus V8 (Endoproteinase-Glu-C) specifically cleaves peptide bonds on the COOH-terminal side of either aspartic or glutamic acids. In the presence of ammonium, the enzyme specificity is limited to glutamic sites. It has a molecular weight of 27 kDa daltons and optimum pH's of 4.0 and 7.8 with hemoglobin as the substrate. Protease S. aureus V8 is inhibited by diisopropylfluorophosphate and monovalent anions such as F-, Cl-, CH3COO-and NO3. Enzyme activity is determined by the casein digestion assay described by Drapeau.
Synonyms
EC 3.4.21.19; Staph aureus V8 Protease; Protease# Staph aureus (Endoproteinase Glu-C); Glutamyl endopeptidase; V8 proteinase# endoproteinase Glu-C; staphylococcal serine proteinase
Introduction
Proteases play a crucial role in regulating a myriad of biological processes. Among these enzyme, V8 protease is an important enzyme with multiple applications. The V8 protease was initially discovered and characterized because of its role in bacterial virulence, particularly in pathogenesis and evasion of host immune responses. However, its relevance extends well beyond microbial physiology, affecting the biotechnological and clinical fields.
Structure
The structure of V8 protease reveals a fascinating conformation with complex functions. As a serine protease, it orchestrates its protein hydrolyzing activity with a catalytic triad of three key amino acids: histidine, aspartate and serine. X-ray crystallography reveals the structure of the V8 protease, which is found to be compact and globular in shape with well-defined substrate binding sites. This structure is essential for its specific and efficient cleavage of peptide bonds in target proteins. In addition, the tertiary structure of V8 protease has a major impact on its stability, pH tolerance, and interactions with regulatory molecules. Intramolecular interactions between its constituent amino acids determine its ability to adapt under different environmental conditions, making it a robust enzyme with potential for multiple applications.
Functions
The catalytic power of V8 protease is reflected in its ability to specifically cleave peptide bonds located after glutamate residues. This selectivity creates a unique cleavage pattern that distinguishes V8 protease from other proteases, making it an invaluable tool for analyzing and processing proteins. Research laboratories utilize its enzymatic activity for protein sequencing, peptide mapping, and structural elucidation, thus improving our understanding of complex protein structures. In addition to its role in research, the physiological function of V8 protease in Staphylococcus aureus is worth exploring. This enzyme enhances bacterial virulence by modulating the host immune response and destroying important host proteins. An understanding of these mechanisms will not only broaden our knowledge of microbial pathogenesis, but also identify potential targets for therapeutic intervention.
Applications
The versatility of V8 protease extends beyond its origins as a bacterial virulence factor into diverse fields. In the field of biotechnology, it plays a crucial role in proteomics research and protein engineering. V8 protease-mediated protein digestion is the cornerstone of mass spectrometry-based proteomics, contributing to the comprehensive identification and characterization of proteins. In addition, the ability of V8 protease to precisely cleave glutamate residues gives researchers the ability to perform site-specific modifications and develop custom-designed protein fragments with tailored functionality.
Clinical Significance
The V8 protease is well known in science and industry and its clinical significance is remarkable. The interaction of this enzyme with host proteins during S. aureus infections highlights its importance in understanding pathogenesis and developing targeted therapeutic strategies. Elucidation of the interaction between V8 protease and immunomodulatory proteins may open new therapeutic avenues for combating S. aureus infections and alleviating their associated complications. In addition, the application of this enzyme in protein analysis and engineering has implications for clinical diagnostics and drug development. Its role in generating defined protein fragments enhances our ability to decipher complex protein structures associated with disease pathology.
