The interaction of anthraquinone dyes with the plasmid-mediated OXA-2 beta-lactamase

Although beta-lactamases do not require any nucleotide co-substrates, the OXA-2 type is inhibited competitively by Cibacron Blue 3GA, and by other anthraquinone dyes, including some simpler compounds with no side chain. The enzyme causes a red shift in the spectrum of Cibacron Blue. The beta-lactamase can be adsorbed in Blue Sepharose and specifically eluted by benzylpenicillin. These results indicate that the binding of anthraquinone dyes is a specific effect similar to that seen with many nucleotide-binding enzymes.