Purification and Properties of  -Lactamases from Serratia marcescens

Abstract

Both a penicillinase and a cephalosporinase were purified from a strain of Serratia marcescens (GN7647) resistant to P-lactam antibiotics. The penicillinase was identical to the type I penicillinase, mediated by Rms2 12 and R-TEM. The purified cephalosporinase, a typical chromosomally mediated enterobacterial P-lactamase, gave a single protein band on polyacrylamide gel electrophoresis and immunoelectrophoresis; the PI was 9.56 and its molecular weight was approximately 37 000. It contained tryptophan but not cysteine. The specific activity was 374 units (mg protein)-' for the hydrolysis of cephaloridine, and the optimal pH was 8.5. Rabbit antisera raised against the purified cephalosporinase showed no cross-reaction in a neutralization test with cephalosporinases produced by other species of Enterobacteriaceae.

A functional classification scheme for beta-lactamases and its correlation with molecular structure

“…Other Serratia marcescens strains that produce AmpC-like cephalosporinases include S7 (334), SC15071 (47), SR50 (202), TN81 (127), and GN7647 (294).…”

In vitro studies on the antibacterial activities of YM-13115, a new broad-spectrum cephalosporin

“…When (12). The compound was also resistant to hydrolysis by common chromosomal cephalosporinases produced by C. freundii (15), E. cloacae (9), P. aeruginosa (10), P. vulgaris (7), and P. cepacia (4 (3,6,11,17,18), namely, in vitro activity at very low concentrations against a very wide variety of gram-negative organisms and high stability against P-lactamases. This study demonstrates that YM-13115 has enhanced activity against gram-negative bacteria and is substantially more active against all members of the Enterobacteriaceae (including known 1-lactamase producers) than ceftazidime, cefoperazone, and cefsulodin.…”

Purification and Properties of β‐Lactamase from Proteus vulgaris

“…The substrate profile of the enzyme was broad and high relative Vmax values were obtained with cephalosporins tested including cefuroxime and cefmenoxime. The cephamycins, cefmetazole and cefoxitin, were resistant to hydrolysis by the enzyme, and, unlike latamoxef, as well as the semi-synthetic penicillins, they inhibited the (8), respectively, and those for S. marcescens are recalculated from Tajima et al (12).…”

“…The amino acid composition of the purified enzyme was determined as previously reported (3) and tryptophan was determined by the methods of FraenkelConrat (2) and of Matsubara and Sasaki (4), and compared with that of typical cephalosporinases produced by P. morganii (3), P. rettgeri (8), and Serratia marcescens (12). Table 2 clearly shows that the amount of proline residue in this purified enzyme from P. vulgaris 1427 was less than that in the other ,B-lactamases.…”