title: Microbial degradation of physiologically active peptides by strain B-9.
abstract: The reaction of some physiologically active peptides with bacterial strain B-9 has been investigated. Bradykinin, β-endorphin, and [Leu(5)]enkephalin were quickly degraded, with half-lives of <5 min. Somatostatin, substance P, and angiotensin I were degraded relatively smoothly, with half-lives of 10 min to 1 h, whereas oxytocin and insulin were slowly degraded, with half-lives of 1 and 4 days, respectively. Vasopressin was barely degraded, with a half-life of >7 days. Linearized vasopressin, prepared by the reductive cleavage of the disulfide bond followed by alkylation with iodoacetamide, was degraded significantly faster than intact vasopressin, with a half-life of 2.5 h. A loop formed by disulfide bond formation was regarded as one of the degradation-resistant factors. Hydrolysis of the peptides in this study took place through cleavage of various peptide bonds, and the strain B-9 may bear similarities to the neutral endopeptidase in terms of its broad selectivity.
authors.affiliation: Department of Pharmacology, Aichi Medical University, Nagakute, Aichi 480-1195, Japan. fumio@ipc-tokai.or.jp
authors.forename: Fumio
authors.initials: F
authors.lastname: Kondo
authors.forename: Shoshiro
authors.initials: S
authors.lastname: Okada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyachi
authors.forename: Miki
authors.initials: M
authors.lastname: Kurita
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Tsuji
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Harada
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010455:Peptides