Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The [3H] phlorizin-binding component of brush border vesicles was enriched in situ by negative purification. Several procedures, known to effect selective solubilization of membrane components, were used separately or in combination to remove proteins unrelated to the binding. Deoxycholate ruptured the vesicles and released 67% of their protein, thereby increasing the specific [3H] phlorizin-binding activity of the pellet three-to fourfold. Extracting the deoxycholate-pellets with either NaI or alkaline solutions released up to 38% of the deoxycholate-insoluble protein without significantly affecting phlorizin binding. The polypeptide composition of the membranes at the different stages was analyzed by NaDodSO4-polyacrylamide gel electrophoresis. A number of polypeptides present in the original vesicles could be ruled out as essential components of the [3H] phlorizin binding entity. Intact and deoxycholate-treated vesicles were subjected to proteolytic attack. Papain liberated sucrase and isomaltase from intact vesicles, but affected neither other Coomassie-stained bands nor phlorizin binding. Neither the protein composition nor the binding properties of sealed vesicles were influenced by trypsin or chymotrypsin. However, all the proteolytic enzymes tested on deoxycholate-treated membranes substantially reduced [3H] phlorizin binding and produced concomitantly the disappearance of several bands from the electrophoretic profile. Pretreatment of vesicles with papain, followed by deoxycholate extraction and incubation in alkaline media, increased the specific binding activity of the membranes up to ninefold by removing close to 90% of the protein. A limited number of polypeptides are suggested as possible candidates for the glycoside-binding site of intestinal brush borders.
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PMID:Partial purification of the sugar carrier of intestinal brush border membranes. Enrichment of the phlorizin-binding component by selective extractions. 52 29

Elasnin, a new human granulocyte elastase inhibitor, produced by the strain of KM-2753 designated as Streptomyces noboritoensis KM--2753 has been isolated from the fermentation broth by column chromatography on silica gel and neutral alumina. Elasnin is a neutral, colorless, and viscous oil (ND17 = 1.4983, [alpha]18D -0.9 degrees, lambdaEtOHmax 291 nm (epsilon, 7,760) having a molecular formula of C24H40O4 (MW 392) as shown by its elemental analysis and mass spectrum. Elasnin markedly inhibits human granulocyte elastase, but it is almost inactive against pancreatic elastase, chymotrypsin, and trypsin. At 1.3 microgram/ml (3.3 X 10(-6) M), elasnin is 50% inhibitory to human elastase, but it causes 50% inhibition of pancreatic elastase at 30.1 microgram/ml (76.8 X 10(-6) M).
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PMID:Isolation and characterization of elasnin, a new human granulocyte elastase inhibitor produced by a strain of Streptomyces. 72 7