Interallelic complementation in hybrid cells derived from human diploid strains deficient in galactose-1-phosphate uridyl transferase activity.

Galactose-1-phosphate uridyl transferase activity has been demonstrated in hybrid cells formed from the fusion of human diploid fibroblasts obtained from different patients with galactosemia. The enzyme produced by the hybrid cells was similar to the normal enzyme in regard to K(m), pH optimum, and electrophoretic mobility on starch gel, but differed in specific activity, V(max) and thermal stability. This is the first reported example of interallelic complementation in fused human diploid cells.