Coenzyme A: pKa and g values

Abstract

The pK_a and γ values at 25°, I 0.1 M, of the mercapto group of coenzyme A were calculated to be 10.35±0.15 and 0.70±0.02 respectively. The γ value was calculated from differences in the partition coefficient of quinazoline between cyclohexane and aqueous buffers and that between cyclohexane and aqueous buffers which contained coenzyme A. The described procedure could be used to obtain γ values of other nucleophilic reagents which, like coenzyme A, absorb u.v, energy strongly.