title: Receptor-binding kinetics of A-14 and A-19 125I-labelled insulin.
abstract: 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.
mesh_terms: D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007328:Insulin / Q000031:analogs & derivatives* / Q000378:metabolism; D007700:Kinetics; D008214:Lymphocytes / Q000378:metabolism; D011972:Receptor, Insulin / Q000378:metabolism*; D013696:Temperature
chemical_list: D007328:Insulin; C029491:insulin, 3-iodo-Tyr(A14)-; D011972:Receptor, Insulin