Open AccessPurification and Properties of Chromosomally Mediated -Lactamase from Citrobacter freundii GN7391
Author(s) -
Masakazu Tajima,
Yuniko Takenouchi,
Shichiro Sugawara,
Matsuhisa Inoue,
Susumu Mitsuhashi
Publication year - 1980
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 179
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/00221287-121-2-449
Subject(s) - citrobacter freundii , cephaloridine , enterobacter cloacae , microbiology and biotechnology , enterobacteriaceae , polyacrylamide gel electrophoresis , antiserum , beta lactamase , citrobacter , chemistry , biology , immunoelectrophoresis , enzyme , biochemistry , cephalosporin , antibiotics , escherichia coli , antibody , genetics , gene
Both a penicillinase and a cephalosporinase are present in a strain of Citrobacter freundii (GN7391) resistant to beta-lactam antibiotics. The penicillinase was identical to the type Ia penicillinases (Type III by Richmond classification), mediated by Rms212 and R-TEM. A cephalosporinase, typical of enterobacteriaceae chromosomal beta-lactamase (Type I by Richmond classification), was purified from the strain. It gave a single protein band on polyacrylamide gel electrophoresis and immunoelectrophoresis; the pI was 8.6 and its molecular weight was approximately 38 000. Cysteine was not found among its amino acids. The specific activity was 388 units (mg protein)-1 for the hydrolysis of cephaloridine, and the optimal pH was 8.0. Rabbit antiserum obtained against the purified enzyme showed cross-reaction with cephalosporinases produced by strains of Enterobacter cloacae in a neutralization test.