Insulin binding and degradation studies on erythrocytes at different temperatures.
Insulin binding of human erythrocytes has been investigated between 0 and 37 degrees C using porcine 125I-insulin/unlabeled porcine insulin and mono [125I] (Tyr-A14)biosynthetic human insulin/ unlabeled biosynthetic human insulin, respectively. Either system exhibited a regular thermodynamical behavior between 0 and 22 degrees C, giving unitary free-energy changes of about -58/ -59 kJ/mol, unitary entropy changes of about +55/ +70 J/K per mol and a reaction heat of -43.1/ -38.3 kJ/mol. From 22 up to 37 degrees C an irregular thermodynamical behavior could be observed, which can be partially explained by an increased insulin degradation during incubation and an additional time-dependent binding of the degradation products.
D000818:Animals; D001667:Binding, Competitive; D004910:Erythrocyte Membrane / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives* / Q000097:blood; D007700:Kinetics; D011972:Receptor, Insulin / Q000378:metabolism*; D013552:Swine; D013696:Temperature
D007328:Insulin; C008147:insulin, iodo-; D011972:Receptor, Insulin