Iodination-induced alterations in biochemical properties of human placental insulin receptor.
Insulin receptors from human placenta have been labeled by using an oxidative iodination procedure (iodogen-mediated or chloramine-T-mediated), Bolton-Hunter reagent or [3H]acetic anhydride. The oxidative iodination procedure reduces the affinity for 131I-insulin and the receptor protein becomes fragmented into smaller pieces with an s20,w value of 5-6. However, treatment with Bolton-Hunter reagent or [3H]acetic anhydride does not alter the Kd of 131I-insulin binding and the s20,w value remains unchanged with respect to the native receptor. It is proposed that for labeling multisubunit sulfhydryl-linked protein drastic oxidative iodination procedures should be avoided.
Ganguly
S
S
Dept of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461.
D000089:Acetic Anhydrides; D000107:Acetylation; D002700:Chloramines; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007457:Iodine Radioisotopes / Q000494:pharmacology*; D007553:Isotope Labeling / Q000379:methods*; D007700:Kinetics; D010084:Oxidation-Reduction; D010920:Placenta / Q000032:analysis*; D011972:Receptor, Insulin / Q000187:drug effects* / Q000378:metabolism; D013388:Succinimides; D014105:Tosyl Compounds; D014508:Urea / Q000031:analogs & derivatives
D000089:Acetic Anhydrides; D002700:Chloramines; D007328:Insulin; D007457:Iodine Radioisotopes; D013388:Succinimides; D014105:Tosyl Compounds; C016300:chloramine-T; C031800:acetic anhydride; C012385:1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycoluril; C022581:Bolton-Hunter reagent; D014508:Urea; D011972:Receptor, Insulin