Insulin receptor binding and degradation in IM-9 cultured human lymphocytes - importance of extracellular degradation.

Insulin degradation in IM-9 cultured human lymphocytes occurs extracellularly. In the presence of 0.1% bovine serum albumin, insulin degradation products are formed that are soluble in 5% trichloroacetic acid. In the presence of 5% bovine serum albumin, the major products of insulin degradation are insoluble in 5% trichloroacetic acid and have little or no biological activity. Inhibition of binding with Concanavalin A or antireceptor antibody does not affect the rate of insulin degradation.