Characterization of cell-bound papain-soluble beta-lactamases in BRO-1 and BRO-2 producing strains of Moraxella (Branhamella) catarrhalis and Moraxella nonliquefaciens

Eur J Clin Microbiol Infect Dis. 1992 Apr;11(4):313-21. doi: 10.1007/BF01962070.

Abstract

In Moraxella (Branhamella) catarrhalis and Moraxella nonliquefaciens strains isolated from clinical specimens in the south of Sweden two variants of beta-lactamase were distinguished by isoelectric focusing (IEF). The BRO-1 (Ravasio type) enzyme was the most common in Branhamella catarrhalis, constituting about 90% of the beta-lactamase found in this species, while the BRO-2 enzyme (1908 type) was as common as BRO-1 in Moraxella nonliquefaciens. The determinants mediating the production of BRO-1 and BRO-2 were both transferable by conjugation. Cell-bound beta-lactamase from reference strains producing BRO-1 and BRO-2 could be solubilized by papain digestion. The isoelectric point of the solubilized enzymes differed distinctly between BRO-1 (pI 6.5) and BRO-2 (pI 6.9). The molecular species of BRO-1 and BRO-2 released by papain digestion were purified by affinity chromatography with phenylboronic acid agarose gel. They had identical molecular weights of approximately 28,000. Their kinetic constants were indistinguishable for a number of substrates and beta-lactamase inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / metabolism
  • Chromatography, Affinity
  • Conjugation, Genetic
  • Electrophoresis, Agar Gel
  • Isoelectric Point
  • Kinetics
  • Microbial Sensitivity Tests
  • Molecular Weight
  • Moraxella / enzymology*
  • Moraxella catarrhalis / enzymology*
  • Papain / metabolism
  • Sweden
  • beta-Lactamases / chemistry
  • beta-Lactamases / isolation & purification
  • beta-Lactamases / metabolism*
  • beta-Lactams

Substances

  • Anti-Bacterial Agents
  • beta-Lactams
  • Papain
  • beta-Lactamases