Watanabe N, Kobayashi M, Ohgaku S, Iwasaki M, Maegawa H, Shigeta Y
Biochim Biophys Acta. 1984 Apr 24;798(3):313-6. doi: 10.1016/0304-4165(84)90104-1.
Receptor-binding kinetics and degradation of tyrosine A-14 and A-19 125I-labelled insulin was studied using cultured human lymphocytes. Receptor-binding ability of A-14 insulin was 1.5-times as high as that of A-19 insulin. Dissociation from receptors on lymphocytes showed no difference between these two labelled insulins. In association studies percent bound of A-14 insulin was 1.5-times as high as that of A-19 insulin at any time after incubation. These results suggested that lower binding affinity of A-19 insulin was due to decreased association rate, but not due to increased dissociation rate. Degradation of A-14 insulin by incubation media of lymphocytes was also 1.5-times as high as that of A-19 insulin.
