Yang Y, Bush K
Wyeth-Ayerst Research, Lederle Laboratories, Pearl River, NY 10965, USA.
FEMS Microbiol Lett. 1996 Apr 1;137(2-3):193-200. doi: 10.1111/j.1574-6968.1996.tb08105.x.
AsbM1, a carbapenem-hydrolyzing beta-lactamase produced by Aeromonas sobria AER 14M, was purified chromatographically, with anion exchange chromatography performed in the absence of Zn2+. The molecular mass of AsbM1 was approximately 34,000; the isoelectric point was 9.1. AsbM1 had high hydrolytic specificity for carbapenems but low hydrolysis rates for penicillins and cephalosporins. AsbM1 was resistant to the commercially available beta-lactamase inhibitors but was inhibited by pCMB and the chelators EDTA and o-phenanthroline. Zinc, an activator for many metallo-beta-lactamases, inhibited AsbM1 with an IC50 of 8 microM. Analysis of the N-terminal sequence (27 amino acids) showed 26% similarity to the CphA metallo-beta-lactamase. Because of the high specificity for carbapenems and the sensitivity to inhibition by Zn2+, AsbM1 should be included in a new subgroup of metallo-beta-lactamases.
嗜水气单胞菌AER 14M产生的碳青霉烯水解β-内酰胺酶AsbM1，通过在无Zn2+的情况下进行阴离子交换色谱法进行色谱纯化。AsbM1的分子量约为34,000；等电点为9.1。AsbM1对碳青霉烯类具有高水解特异性，但对青霉素和头孢菌素的水解率较低。AsbM1对市售的β-内酰胺酶抑制剂具有抗性，但被对氯汞苯甲酸以及螯合剂乙二胺四乙酸和邻菲啰啉抑制。锌是许多金属β-内酰胺酶的激活剂，以8 microM的IC50抑制AsbM1。对N端序列（27个氨基酸）的分析显示与CphA金属β-内酰胺酶有26%的相似性。由于对碳青霉烯类的高特异性以及对Zn2+抑制的敏感性，AsbM1应归入金属β-内酰胺酶的一个新亚组。
