» Articles » PMID: 4597709

Characterization of R Factor Beta-lactamases by the Acidimetric Method

Overview
Specialty Pharmacology
Date 1973 Jan 1
PMID 4597709
Citations 16
Authors
Affiliations
Soon will be listed here.
Abstract

The properties and regulation of beta-lactamases produced by certain R factors derived from ampicillin-resistant strains of Escherichia coli and Klebsiella were characterized. beta-Lactamase activity was determined by the acidimetric method with phenol red as indicator. The sensitivity of this assay was increased by employing phosphate buffer at a final concentration of 0.4 mm; as little as 0.05 unit (1 unit equals the amount of beta-lactamase that hydrolyzes 1 mumole of benzyl penicillin per hr at pH 7.6 and 25 C) could be detected. This assay is rapid and convenient and appears to be superior to other methods currently employed to assay R factor beta-lactamases. Two classes of beta-lactamases were distinguished on the basis of substrate profile, heat inactivation, and K(m) values. The regulation of most of these R factor beta-lactamases, like certain other R factor enzymes, is subject to cyclic adenosine monophosphate-mediated catabolite repression.

Citing Articles

Fluorescent Mesoporous Nanoparticles for β-Lactamase Screening Assays.

Tummala S, Huang W, Wu B, Chang K, Ho Y ChemistryOpen. 2020; 9(10):1074-1081.

PMID: 33117628 PMC: 7582675. DOI: 10.1002/open.202000221.


A circularly permuted beta-lactamase as a novel reporter for evaluation of protein cyclization efficiency.

Kwon J, Bal J, Hwang H, Kim J J Microbiol. 2008; 46(4):456-61.

PMID: 18758738 DOI: 10.1007/s12275-008-0106-2.


R-mediated beta-lactamases and episomal resistance to the beta-lactam drugs in different bacterial hosts.

Kontomichalou P, Papachristou E, Levis G Antimicrob Agents Chemother. 1974; 6(1):60-72.

PMID: 15828172 PMC: 429048. DOI: 10.1128/AAC.6.1.60.


Characterization of eight beta-lactamases of Gram-negative bacteria.

Sawai T, Kanno M, Tsukamoto K J Bacteriol. 1982; 152(2):567-71.

PMID: 6752115 PMC: 221503. DOI: 10.1128/jb.152.2.567-571.1982.


R6K plasmid replication: influence of chromosomal genotype in minicell-producing strains of Escherichia coli K-12.

Macrina F, Weatherly G, Curtiss 3rd R J Bacteriol. 1974; 120(3):1387-400.

PMID: 4612021 PMC: 245926. DOI: 10.1128/jb.120.3.1387-1400.1974.


References
1.
Datta N, KONTOMICHALOU P . Penicillinase synthesis controlled by infectious R factors in Enterobacteriaceae. Nature. 1965; 208(5007):239-41. DOI: 10.1038/208239a0. View

2.
Datta N, Richmond M . The purification and properties of a penicillinase whose synthesis is mediated by an R-factor in Escherichia coli. Biochem J. 1966; 98(1):204-9. PMC: 1264816. DOI: 10.1042/bj0980204. View

3.
OCALLAGHAN C, Kirby S, Wishart D . Microbiological assay of mixed cephalosporins. Antimicrob Agents Chemother (Bethesda). 1967; 7:716-22. View

4.
Burman L, Nordstrom K, Boman H . Resistance of Escherichia coli to penicillins. V. Physiological comparison of two isogenic strains, one with chromosomally and one with episomally mediated ampicillin resistance. J Bacteriol. 1968; 96(2):438-46. PMC: 252316. DOI: 10.1128/jb.96.2.438-446.1968. View

5.
Evans J, Galindo E, Olarte J, Falkow S . Beta-lactamase of R factors. J Bacteriol. 1968; 96(4):1441-2. PMC: 252489. DOI: 10.1128/jb.96.4.1441-1442.1968. View