Insulin binding in human skeletal muscle.
Insulin binding to crude plasma membranes derived from human skeletal muscle was characterized. Incubations were performed for 22 h at 4 degrees C. Typical insulin binding characteristics were found, i.e., (a) specificity for insulin, (b) pH sensitivity, (c) dissociation of insulin by the addition of excess insulin and (d) concave Scatchard curves. Half-maximal inhibition of 125I-labeled-insulin binding occurred at 1 X 10(-8) M. Affinity constants were 0.76 X 10(9) and 0.02 X 10(9) M-1 for the high- and low-affinity receptor (2-site model), respectively, and the corresponding receptor numbers were 89 and 1450 fmol/mg protein, respectively. The procedures employed permit the determination of insulin binding to small quantities of human muscle (approx. 250 mg).
D000328:Adult; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives / Q000378:metabolism; D007700:Kinetics; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism*; D011972:Receptor, Insulin / Q000378:metabolism*
D007328:Insulin; C008147:insulin, iodo-; D011972:Receptor, Insulin