Inhibition of anion transport across red blood cells with 1,2-cyclohex-anedione

Abstract

The effects of three different α dicarbonyl reagents on SO 4 equilibrium exchange across the red cell membrane have been studied. It was found that 1,2-cyclohexanedione, an arginine specific reagent [1], causes inhibition of transport and a reduction of the capacity of the band 3 protein to bind the specific transport inhibitor H 2DIDS. The effect on the H 2DIDS binding capacity was, however, considerably smaller than the inhibition of sulfate transport indicating that the inhibition involved a modification of sites other than the H 2DIDS binding site. Squaric acid and 1,3-cyclohexanedione produced no inhibition under conditions where 1,2-cyclohexanedione was fully inhibitory. The results suggest that besides the lysine residues [2] involved in H 2DIDS-binding guanidino groups may also play a role in anion transport across the red blood cell membrane.