help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lowe, W.
Right arrow Articles by LeRoith, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lowe, W., Jr
Right arrow Articles by LeRoith, D.

Endocrinology, Vol 118, 1669-1677, Copyright © 1986 by Endocrine Society

ARTICLES

Insulin receptors from guinea pig liver and brain: structural and functional studies

W Lowe Jr and D LeRoith

We studied the structural and functional characteristics of insulin receptors from guinea pig liver and brain. Binding to crude membrane preparations of liver and brain was time, temperature, and pH dependent. Maximal specific binding to liver crude membrane preparations was 16.4 +/- 0.5%, and that to brain crude membrane preparations was 10.4 +/- 1.8%. Specificity studies demonstrated typical affinities for insulin receptors with chicken insulin greater than porcine insulin greater than human proinsulin greater than desoctapeptide insulin in both liver and brain. Antiinsulin receptor antiserum inhibited binding of [125I]insulin to both liver and brain crude membrane preparations. Electrophoresis performed under reducing conditions after affinity cross-linking of liver and brain insulin receptors with [125I]insulin revealed labeled proteins (alpha-subunit) with apparent mol wt of 136,000 in liver and 121,000 in brain. Treatment of liver and brain receptors with both endoglycosidase H and endoglycosidase F increased the electrophoretic mobility of the alpha- subunit. [125I]Insulin cross-linked receptors from both liver and brain adsorbed to and eluted from wheat germ agglutinin columns in a similar manner, as demonstrated by binding and sodium dodecyl sulfate- polyacrylamide gel electrophoresis. In solubilized lectin-purified receptor preparations from liver and brain, insulin stimulated the phosphorylation of the beta-subunit and exogenous substrates. When the delta-kinase activity, as measured by exogenous substrate phosphorylation, of the brain and liver preparations was normalized to the maximal bound to free ratio of the preparations, the delta-kinase activity was about 4-fold greater in brain than in liver. These studies suggest that the differences between brain and liver insulin receptor alpha-subunits previously demonstrated in rats are also present in guinea pigs.


This article has been cited by other articles:


Home page
 FASEB J.Home page
W.-Q. Zhao, F. G. De Felice, S. Fernandez, H. Chen, M. P. Lambert, M. J. Quon, G. A. Krafft, and W. L. Klein
Amyloid beta oligomers induce impairment of neuronal insulin receptors
FASEB J, January 1, 2008; 22(1): 246 - 260.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1986 by The Endocrine Society