Characterization of eight beta-lactamases of Gram-negative bacteria.
Eight kinds of beta-lactamases produced by gram-negative bacteria were characterized by the following properties: molecular weight, isoelectric point, pH optimum, molecular activity, immunochemical reactivity, and kinetic parameters with respect to twelve kinds of common beta-lactam antibiotics. These beta-lactamases included two types of penicillinases mediated by R plasmids and six kinds of species-specific cephalosporinases. To determine a reliable value of the kinetic parameter, Km, we introduced a continuous and acidimetric assay method of beta-lactamase activity with a pH stat.
D002954:Citrobacter / Q000201:enzymology*; D004754:Enterobacter / Q000201:enzymology*; D004755:Enterobacteriaceae / Q000201:enzymology*; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D011511:Proteus / Q000201:enzymology*; D012706:Serratia marcescens / Q000201:enzymology*; D013045:Species Specificity; D013379:Substrate Specificity; D001618:beta-Lactamases / Q000378:metabolism*
D001618:beta-Lactamases