title: The use of analytical isoelectric focusing for detection and identification of beta-lactamases.
abstract: BETA-Lactamases (EC. 3.5.2.6) from strains of Gram-negative bacteria have been studied using analytical isoelectric focusing. This permits a visual comparison of the patterns of beta-lactamase bands produced by enzymes from different organisms. Purification of crude intracellular preparations is unnecessary and the technique is sufficiently sensitive to demonstrate beta-lactamase in mutants previously reported to lack the enzyme. R that have not been distinguished from one another biochemically or immunologically can be differentiated by isoelectric focusing. Conversely, the enzymes specified by the R factors RTEM, R1 and RGN14, with identical isoelectric focusing patterns have the same biochemical properties. Chromosomal and R-factor-mediated beta-lactamases from single strains have been separated and their identities confirmed by immunoisoelectric focusing. R factor-mediated enzymes gave identical isoelectric focusing patterns irrespective of the host strain. Isoelectric focusing can therefore be used to observe the transfer of beta-lactamases carried by R factors.
mesh_terms: D000581:Amidohydrolases / Q000302:isolation & purification*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000201:enzymology*; D002474:Cell-Free System; D002510:Cephalosporinase / Q000302:isolation & purification* / Q000378:metabolism; D003227:Conjugation, Genetic; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000201:enzymology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology; D007525:Isoelectric Focusing / Q000379:methods; D007709:Klebsiella / Q000201:enzymology; D009154:Mutation; D010405:Penicillinase / Q000302:isolation & purification* / Q000378:metabolism; D011511:Proteus / Q000201:enzymology; D011513:Proteus mirabilis / Q000201:enzymology; D011550:Pseudomonas aeruginosa / Q000201:enzymology; D013045:Species Specificity; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D000581:Amidohydrolases; D002510:Cephalosporinase; D010405:Penicillinase