Properties of receptors for epidermal growth factor in detergent solution: Evidence for heterogeneous aggregated states
- 1 January 1980
- journal article
- research article
- Published by Wiley in Journal of Supramolecular Structure
- Vol. 14 (4), 511-525
- https://doi.org/10.1002/jss.400140409
Abstract
Between 60% and 100% of epidermal growth factor (EGF) binding activity was recovered from membranes of the A431 human epidermoid carcinoma cell line treated with solutions containing the nonionic detergent Triton X-100. Approximately half of the recovered binding activity was sedimented at low centrifugal forece and hence was operationally insoluble in nonionic detergent solution. Receptors in both the detergent-soluble and -insoluble fractions displayed similar affinities for 125I-EGF, and the values were in good agreement with those obtained for receptors in untreated membranes. The receptors in both fractions also formed identical direct linkage complexes with 125I-EGF in similar yield, providing no evidence for partitioning of different molecular species of EGF receptors in the detergent-soluble and -insoluble fractions. Gel chromatography of the detergent-soluble membrane fraction on Sepharose 6-B revealed heterogeneity of 125I-EGF binding activity; the smallest and most monodisperse peak of activity resolved by this technique was eluted at a Stokes radius of 95 Å. Operationally soluble 125I-EGF binding activity also behaved heterogeneously during velocity sedimentation; more than half the activity sedimented more rapidly than the apparently monidisperse, 7S form. An average of less than half the nonionic detergent-solubilized activity recovered from 10 independent membrane preparations behaved as an apparently monodisperse entity. Since a maximum of 60% of 125I-EGF binding activity was operationally soluble, less than 25% of the total EGF binding activity was recovered in an apparently monodisperse form. The remaining 75% of the EGF receptors displayed a marked tendency to exist as aggregates in nonionic detergent solutions.Keywords
This publication has 28 references indexed in Scilit:
- Transglutaminase is essential in receptor-mediated endocytosis of α2-macroglobulin and polypeptide hormonesNature, 1980
- Direct linkage of EGF to its receptor: Characterization and biological relevanceJournal of Supramolecular Structure, 1980
- Identification of the EGF receptor on 3T3 cells by surface‐specific iodination and gel electrophoresisFEBS Letters, 1979
- Solubilization of membrane receptor for epidermal growth factorLife Sciences, 1979
- Local aggregation of hormone–receptor complexes is required for activation by epidermal growth factorNature, 1979
- Regulation of epidermal growth factor (EGF) receptor activity during the modulation of protein synthesisJournal of Cellular Physiology, 1979
- Hormone‐induced modification of EGF receptor proteolysis in the induction of EGF actionJournal of Supramolecular Structure, 1979
- Epidermal growth factor stimulates phosphorylation in membrane preparations in vitroNature, 1978
- Collection of insulin, EGF and α2-Macroglobulin in the same patches on the surface of cultured fibroblasts and common internalizationCell, 1978
- Solubilization of membranes by detergentsBiochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1975