Rhodanese isozymes in human tissues.

An investigation of a range of tissue homogenates by various electrophoretic methods, followed by staining for specific enzyme activity, has revealed a series of isozymes of human rhodanese. Polyacrylamide gel isoelectric focusing provided the most data and rhodanese activity was found in all of the tissues examined. The simplest isozyme pattern was found in red cell lysates; liver homogenates generated the most complex pattern which included the 'red cell' forms together with a set of more basic 'tissue' isozymes. Variation in isozyme patterns thought to be attributable to storage changes affecting reactive sulphydryl residues was observed in 'red cell' rhodanese but no genetic variants of either 'red cell' or 'tissue' rhodanese were encountered in a study of material from the European population. We conclude that 'red cell' and 'tissue' rhodanese are determined by separate genes but more than one locus may be concerned with the synthesis of the heterogeneous 'tissue' isozymes.