Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The amino acid sequence of the enzyme cyanase (cyanate hydrolase) from Escherichia coli has been determined by automatic Edman degradation of the intact protein and of its component peptides. The primary peptides used in the sequencing were produced by cyanogen bromide cleavage at the methionine residues, yielding 4 peptides plus free homoserine from the NH2-terminal methionine, and by trypsin cleavage at the 7 arginine residues after acetylation of the lysines. Secondary peptides required for overlaps and COOH-terminal sequences were produced by chymotrypsin or clostripain cleavage of some of the larger peptides. The complete sequence of the cyanase subunit consists of 156 amino acid residues (Mr 16,350). Based on the observation that the cysteine-containing peptide is obtained as a disulfide-linked dimer, it is proposed that the covalent structure of cyanase is made up of two subunits linked by a disulfide bond between the single cystine residue in each subunit. The native enzyme (Mr 150,000) then appears to be a complex of four or five such subunit dimers.
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PMID:The amino acid sequence of Escherichia coli cyanase. 633 48

Porphyromonas gingivalis is known to be a major etiologic agent in the onset and progression of chronic periodontitis. Among various virulence factors that this bacterium produces, Arg- and Lys-specific cysteine proteinases (gingipains) are believed to be major determinants of the pathogenicity of P. gingivalis. Here, we report on our finding that there are inhibitors of these cysteine proteinases in a rice protein fraction. Comprehensive affinity chromatography and MS analyses resulted in the identification of 17 Arg-gingipain (Rgp)-interacting proteins in the rice endosperm. Of these, four proteins (i.e., a 26 kDa globulin, a plant lipid transfer/trypsin-alpha amylase inhibitor, the RA17 seed allergen, and an alpha amylase/trypsin inhibitor) were estimated to account for 90% of the Rgp inhibitory activity in the rice protein fraction, using a two-dimensional gel system of double-layer reverse zymography. In addition, a synthetic peptide derived from an Rgp-interacting protein, cyanate hydratase, could inhibit the growth of P. gingivalis and showed inhibitory activity against both the Arg- and Lys-gingipains. These results suggest that these rice proteins may be useful as nutraceutical ingredients for the prevention and management of periodontal diseases.
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PMID:Identification of proteinaceous inhibitors of a cysteine proteinase (an Arg-specific gingipain) from Porphyromonas gingivalis in rice grain, using targeted-proteomics approaches. 1969 Dec 86