title: Quantitative correlation between penicillin resistance and beta-lactamase activity specified by the R plasmids R1, R1 bla-45, and RP1 in Escherichia coli K-12.
abstract: A mutant of the R plasmid R1 which synthesizes a beta-lactamase with altered kinetic characteristics was isolated. The level of penicillin resistance specified by this plasmid was correctly predicted from the properties of the wild-type R1 according to a simple theoretical model published by Zimmermann and Rosselet (Antimicrob. Agents Chemother. 12:368--372, 1977). The model also accounts for the high level of penicillin resistance specified by the R plasmid RP1.
mesh_terms: D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D007700:Kinetics; D010403:Penicillin Resistance; D010539:Permeability; D011815:R Factors; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D003470:Culture Media; D001618:beta-Lactamases