Interaction of Cibacron Blue 3GA and Remazol Brilliant Blue R with the nucleotide binding site of lactate dehydrogenase and (Na+ + K+)-ATPase.

The interaction of Cibacron Blue 3GA (C.I.2) and Remazol Brillant Blue R (C.I.19) with purified preparations of Lactate dehydrogenase (LDH) and (Na+ + K+)-ATPase was studied by means of the enzyme kinetics method. LDH was found to be inhibited by both C.I.2 and C.I.19, with the former being a stronger inhibitor. This may be explained by the fact that in contrast to C.I.19, C.I.2 resembles the whole molecule of the specific cofactor. (Na+ + K+)-ATPase activity was inhibited by both dyes to approximately similar degree. C.I.2 and C.I.19 resemble the ATP molecule to approximately similar extent, particularly as concerns the molecule shape and size. The results obtained confirmed the applicability of C.I.2 and C.I.19 as nucleotide-specific ligands.