Negative and positive site-site interactions, and their modulation by pH, insulin analogs, and monoclonal antibodies, are preserved in the purified insulin receptor

Journal Article · Tue Nov 01 04:00:00 EST 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.22.8400· OSTI ID:5478553

Wang, Chihchen; Goldfine, I D; Fukita-Yamaguchi, Yoko; Gattner, H G; Brandenburg, D; De Meyts, P ^[1]

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1. City of Hope National Medical Center, Duarte, CA (USA)

The kinetic properties of the insulin receptor were studied in solution after its purification to homogeneity. Dissociation of {sup 125}I-labeled insulin at a 1:50 dilution was not first order; unlabeled insulin at physiological concentrations accelerated the dissociation rate with a maximal effect at {approx} 17 nM. At higher concentrations, the unlabeled insulin slowed the dissociation rate. Maximal acceleration was seen at pH 8.0. The ability to accelerate the dissociation rate was diminished with (Leu{sup B24})insulin and suppressed with desoctapeptide, (Leu{sup B25}), (Leu{sup B24,B25}), desalanine-desasparagine, and desheptapeptide insulins, all of which slowed the dissociation at high concentrations. Monoclonal antibodies to the insulin receptor {alpha} subunit (MA-5, MA-10, MA-20, and MA-51) all competed for insulin binding to the purified receptor. MA-10 and MA-51 accelerated the dissociation of {sup 125}I-labeled insulin, while MA-5 and MA-20 slowed the off rate. Thus, all the aspects of both negatively and positively cooperative site-site interactions previously described in whole cells are present in solubilized purified receptors, demonstrating that these interactions represent intrinsic properties of the receptor molecule, most likely as a result of ligand-induced conformational changes.

• OSTI ID: 5478553
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 85:22; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ANTIBODIES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
DOSE-RESPONSE RELATIONSHIPS
ELECTRON CAPTURE RADIOISOTOPES
FEMALES
FETAL MEMBRANES
HORMONES
INSULIN
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MAN
MEMBRANE PROTEINS
MEMBRANES
MONOCLONAL ANTIBODIES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PH VALUE
PLACENTA
POLYMERIZATION
PRIMATES
PROTEINS
PURIFICATION
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
SUBSTRATES
VERTEBRATES
WOMEN