Abstract
Glycinin acidic subunit A1a and its trypsinized product (A1a/Try) were found to potentiate insulin-mediated antilipolysis antagonized to isoproterenol in 3T3-L1 preadipocytes and adipocytes. A1a and A1a/Try protected 3T3-L1 preadipocytes from the cytotoxic action of trypan blue. Furthermore, the oxygen consumption in rat liver mitochondria that was accelerated during incubation, which implies an increase in the permeability of the inner membrane, was suppressed by the addition of A1a and A1a/Try. On the other hand, the chymotryptic product of A1a did not show such effects. These results suggest that specific amino acid alignment is required for the functions of A1a and that the insulin-stimulating action of A1a and A1a/Try is closely correlated with their stabilizing effect on cell membranes.
