Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
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Colonies of Neisseria gonorrhoeae JS3, each bearing a predominate protein II (PII) type, were derived from a progenitor transparent colony. Five distinct PIIs were identified and isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The PII bands were excised from gels of unlabeled whole cells and from gels containing lysates of surface-radioiodinated bacteria. These were subjected to alpha-chymotrypsin digestion and two-dimensional peptide mapping, which allowed for a comparison of both the primary structures of the PIIs and the identification of surface-exposed regions of the molecules. The results demonstrated that PIIs are unrelated to either Protein I or Protein III in structure but are closely related to one another, sharing about two-thirds of the peptides generated by alpha-chymotrypsin. The remaining third of the peptides varied with each PII, resulting in unique portions of the molecule being exposed on the bacterial surface. However, the variable peptides were not always among the exposed peptides, suggesting that the structural differences in the PIIs occur at a discrete site (or sites) of the PII molecule and not randomly throughout the protein. Such alterations can result in the exposure of distant, nonvariant portions of the molecule to the surface, perhaps by conformational changes. These bacteria can thus present a variety of new immunodeterminant sites to the host during the course of disease.
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PMID:Structure and surface exposure of protein IIs of Neisseria gonorrhoeae JS3. 392 62

Proteolytic enzymes inhibit the growth of some strains and opacity variants of Neisseria gonorrhoeae. To understand the inhibitory effects of these enzymes, we examined several strains to determine the actions of proteases on the three predominant proteins in gonococcal outer membranes. namely, the major outer membrane protein (protein I), the sometimes-expressed opaque protein (protein II), and protein III. In a comparison of the protein I species expressed by different strains, we observed a pattern based on subunit molecular weight and susceptibility to enzymatic degradation. Protein I species having molecular weights of 34,000 were more susceptible to proteolysis, whereas protein I species having molecular weights of 33,000 were less susceptible, and protein I species having molecular weights of 32,000 were resistant. This pattern was observed both in intact cells and in purified outer membranes. All of the enzymes degraded protein II, but this susceptibility appeared to be influenced in part by the species of protein I present. Protein III was resistant to all of the proteolytic enzymes tested. Based on the resulting fragments from each proteolytic cleavage of proteins I and II and their membrane associations, we suggest how these proteins may be arranged in intact membranes. Our data suggested the presence of an endogenous gonococcal enzyme. This enzyme appeared to degrade proteins I and II into fragments resembling the fragments resulting from the action of chymotrypsin.
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PMID:Effects of proteolytic enzymes on the outer membrane proteins of Neisseria gonorrhoeae. 679 Apr 41