Sulfhydryl groups in the red cells of normal and glucose-6-phosphate dehydrogenase-defficient subjects

Abstract The sulfhydryl content of normal and glucose-6-phosphate dehydrogenase ( d -glucose-6-phosphate: NADP oxidoreductase, EC 1.1.1.49)-deficient intact red cells and cell membranes has been investigated by a spectrophotometric procedure with 5,5′-dithiobis (2-nitrobenzoic acid) and by the equilibrium binding of radioactively labelled mercury. No significant difference in the membrane sulfhydryl groups was detected between the two kinds od cells. On the other hand a slight, but statistically significant deficiency of protein sulfhydryl groups in whole red cells of glucose-6-phosphate dehydrogenase-deficient subjects was demonstrated by both methods of examination. The possible causes of this deficiency are discussed.