Comparison of solubilized and purified plasma membrane and nuclear insulin receptors

Journal Article · Tue Jan 12 04:00:00 EST 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00401a056· OSTI ID:5438212

Wong, K Y; Hawley, D; Vigneri, R; Goldfine, I D

Prior studies have detected biochemical and immunological differences between insulin receptors in plasma membranes and isolated nuclei. To further investigate these receptors, they were solubilized in Triton X-100 partially purified by wheat germ agglutinin-agarose chromatography. In these preparations, the nuclear and plasma membrane receptors had very similar pH optima (pH 8.0) and reactivities to a group of polyclonal antireceptor antibodies. Further, both membrane preparations had identical binding activities when labeled insulin was competed for by unlabeled insulin (50% inhibition at 800 pM). Next, nuclear and plasma membranes were solubilized and purified to homogeneity by wheat germ agglutinin-agarose and insulin-agarose chromatography. In both receptors, labeled insulin was covalently cross-linked to a protein of 130 kilodaltons representing the insulin receptor ..cap alpha.. subunit. When preparations of both receptors were incubated with insulin and then adenosine 5'-(..gamma..-/sup 32/P)triphosphate, a protein of 95 kilodaltons representing the insulin receptor ..beta.. subunit was phosphorylated in a dose-dependent manner. These studies indicate, therefore, that solubilized plasma membrane and nuclear insulin receptors have similar structures and biochemical properties, and they suggest that they are the same (or very similar) proteins.

• Research Organization: Mount Zion Hospital and Medical Center, San Francisco, CA
• OSTI ID: 5438212
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:1; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL REACTIONS
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
DOSE-RESPONSE RELATIONSHIPS
HORMONES
INSULIN
ISOTOPES
LIGHT NUCLEI
MEMBRANE PROTEINS
MEMBRANES
MOLECULAR STRUCTURE
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PH VALUE
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORYLATION
POLYMERIZATION
PROTEINS
PURIFICATION
RADIOISOTOPES
RECEPTORS