Chromosomally encoded cephalosporin-hydrolyzing beta-lactamase of Proteus vulgaris RO104 belongs to Ambler's class A

Biochim Biophys Acta. 1994 Jul 20;1207(1):31-9. doi: 10.1016/0167-4838(94)90048-5.

Abstract

Proteus vulgaris RO104 strain produces a chromosomally encoded beta-lactamase that confers resistance to various beta-lactam antibiotics including methoxyimino third-generation cephalosporins. The beta-lactamase hydrolyzes first- and second-generation cephalosporins efficiently and cefotaxime to a lesser extent. Catalytic activity is inhibited by low concentrations of clavulanic acid and sulbactam. By its broad-spectrum substrate profile, beta-lactamase of Proteus vulgaris RO104 belongs to the group 2e defined by Bush. The protein purified to homogeneity by a four-step procedure was characterized by a pI of 8.31 and a specific activity of 1200 U/mg. The beta-lactamase was digested by trypsin, endoproteinase Asp-N and chymotrypsin. Amino-acid sequence determinations of the resulting peptides allowed the alignment of the 271 amino-acid residues of the protein which did not contain any cysteine residue. From amino-acid sequence comparisons, Proteus vulgaris RO104 beta-lactamase was found to share about 68% identity with the chromosomally mediated beta-lactamases of Klebsiella oxytoca D488 and E23004. Therefore, the cephalosporin-hydrolyzing beta-lactamase of Proteus vulgaris RO104 belongs to Ambler's class A.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cephalosporins / metabolism*
  • Kinetics
  • Molecular Sequence Data
  • Proteus vulgaris / enzymology
  • Proteus vulgaris / genetics*
  • Sequence Alignment
  • beta-Lactamases / classification
  • beta-Lactamases / genetics*
  • beta-Lactamases / isolation & purification

Substances

  • Cephalosporins
  • beta-Lactamases