Regulation of insulin receptor-associated tyrosine kinase by a polyclonal IgG.
The effect of a polyclonal anti-insulin receptor antibody (pIgG) on the insulin receptor tyrosine kinase (IRTK) activity toward poly-(Glu-Tyr) was examined using wheat germ agglutinin agarose-purified insulin receptors from rat liver membranes. The main effect of pIgG was a reduction of Vmax (from 60.8 to 31.8 pmol/min/mg), without changes of Km, when IRTK was activated by insulin. In contrast, when IRTK was activated by ATP preincubation, pIgG was unable to affect the reaction, suggesting that IRTK possesses at least two regulatory mechanisms, one of which can be affected by pIgG.
Gherzi
R
R
Department of Internal Medicine, University of Genoa, Italy.
Cordera
R
R
Andraghetti
G
G
De Pirro
R
R
Freidenberg
G R
GR
Lauro
R
R
Adezati
L
L
D000818:Animals; D006801:Humans; D007003:Hypoglycemia / Q000276:immunology; D007074:Immunoglobulin G / Q000302:isolation & purification; D007425:Intracellular Membranes / Q000276:immunology; D007700:Kinetics; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008861:Microsomes / Q000276:immunology; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000276:immunology* / Q000378:metabolism; D011972:Receptor, Insulin; D011975:Receptors, Mitogen / Q000302:isolation & purification / Q000378:metabolism; D014909:Wheat Germ Agglutinins / Q000378:metabolism
D007074:Immunoglobulin G; D011975:Receptors, Mitogen; D014909:Wheat Germ Agglutinins; C027503:wheat germ agglutinin receptor; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin