title: Active site peptide of beta-lactamase from Shigella flexneri UCSF-129.
abstract: The peptide containing the catalytic serine of beta-lactamase from Shigella flexneri was determined as V-D-E-R-F-P-M-M-S*-T-F-K. It is a local pathogenic strain which produces intestinal problems, especially in children. The highly purified enzyme was prepared by affinity chromatography in phenylboronic acid-agarose gels. The peptide was obtained by tryptic hydrolysis, with further purification by Bio-Gel P-4, Sephadex QAE-25 and Sephadex SP-25. The relevance of the serine, lysine and arginine residues was mainly shown by the loss of enzymatic activity after specific chemical modifications. Finally, this enzyme was classified as A, according to the similarity of this peptide with that of class A beta-lactamases such as R-TEM 1 and 2.
authors.affiliation: Departamento de Polímeros, Facultad de Ciencias Químicas, Universidad de Concepción, Chile.
authors.forename: M
authors.initials: M
authors.lastname: Campos
authors.forename: H
authors.initials: H
authors.lastname: González
authors.forename: G
authors.initials: G
authors.lastname: Bocaz
authors.forename: O
authors.initials: O
authors.lastname: Vásquez
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D002648:Child; D006801:Humans; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D012763:Shigella flexneri / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D001618:beta-Lactamases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D001618:beta-Lactamases