title: Selective cleavage of a peptide antibiotic, colistin by colistinase.
abstract: A colistin-inactivating enzyme, colistinase was produced by Bacillus polymyxa var. colistinus KOYAMA, a colistin-producing microorganism. The crude colistinase was fractionated as two components (colistinase I and II) by Sephadex G-50 gel filtration. Colistinase II was further purified and then, it showed as a single band in polyacrylamide disc gel electrophoresis. The molecular weight of colistinase II was about 20,000 by Sephadex G-100 gel filtration and the isoelectric point was at about 8.3. Colistinase II cleaved specifically between the 2,4-diaminobutyric acid of the side chain and 2,4-diaminobutyric acid adjacent in the cyclic peptide portion of colistin molecule.
mesh_terms: D003091:Colistin / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D008970:Molecular Weight; D012697:Serine Endopeptidases; D013379:Substrate Specificity
chemical_list: D010450:Endopeptidases; D012697:Serine Endopeptidases; C030904:colistinase; D003091:Colistin