Journal article
Functional properties of an isolated alpha beta heterodimeric human placenta insulin-like growth factor 1 receptor complex
Biochemistry (Easton), Vol.27(9), pp.3234-3242
05/03/1988
DOI: 10.1021/bi00409a017
PMID: 2968813
Abstract
Treatment of human placenta membranes at pH 8.5 in the presence of 2.0 mM dithiothreitol (DTT) for 5 min, followed by the simultaneous removal of the DTT and pH adjustment to pH 7.6, resulted in the formation of a functional alpha beta heterodimeric insulin-like growth factor 1 (IGF-1) receptor complex from the native alpha 2 beta 2 heterotetrameric disulfide-linked state. The membrane-bound alpha beta heterodimeric complex displayed similar curvilinear 125I-IGF-1 equilibrium binding compared to the alpha 2 beta 2 heterotetrameric complex. Triton X-100 solubilization of the alkaline pH and DTT-pretreated placenta membranes, followed by Bio-Gel A-1.5m gel filtration chromatography, was found to effectively separate the alpha 2 beta 2 heterotetrameric and alpha beta heterodimeric IGF-1 receptor species, 125I-IGF-1 binding to both the isolated alpha 2 beta 2 heterotetrameric and alpha beta heterodimeric complexes demonstrated a marked straightening of the Scatchard plots, compared to the placenta membrane-bound IGF-1 receptors, with a 2-fold increase in the high-affinity binding component. Similar to the membrane-bound IGF-1 receptor species, the 125I-IGF-1 binding properties between the alpha 2 beta 2 heterotetrameric and alpha beta heterodimeric complexes were not significantly different. IGF-1 stimulation of IGF-1 receptor autophosphorylation indicated that the ligand-dependent activation of alpha beta heterodimeric protein kinase activity occurred concomitant with the reassociation into a covalent alpha 2 beta 2 heterotetrameric state.
Details
- Title: Subtitle
- Functional properties of an isolated alpha beta heterodimeric human placenta insulin-like growth factor 1 receptor complex
- Creators
- S M Feltz - Department of Physiology and Biophysics, University of Iowa, Iowa City 52242M L SwansonJ A WemmieJ E Pessin
- Resource Type
- Journal article
- Publication Details
- Biochemistry (Easton), Vol.27(9), pp.3234-3242
- DOI
- 10.1021/bi00409a017
- PMID
- 2968813
- NLM abbreviation
- Biochemistry
- ISSN
- 0006-2960
- eISSN
- 1520-4995
- Publisher
- United States
- Grant note
- DK33823 / NIDDK NIH HHS DK25295 / NIDDK NIH HHS
- Language
- English
- Date published
- 05/03/1988
- Academic Unit
- Molecular Physiology and Biophysics; Psychiatry; Iowa Neuroscience Institute; Neurosurgery
- Record Identifier
- 9984003911502771
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