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 Sergi, I.
Right arrow Articles by Ronin, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sergi, I.
Right arrow Articles by Ronin, C.

Endocrinology, Vol 128, 3259-3268, Copyright © 1991 by Endocrine Society

ARTICLES

Immunoreactive and bioactive isoforms of human thyrotropin

I Sergi, MJ Papandreou, G Medri, C Canonne, B Verrier and C Ronin
Laboratoire de Biochimie, URA 1179 CNRS, Marseille, France.

Isoforms of intrapituitary human TSH were separated by gel isoelectrofocusing, and their immunoreactivity analyzed by subsequent immunoblotting using polyclonal and monoclonal antibodies. Under these conditions, TSH polymorphism could be resolved as seven major isoforms (pI 8.6, 8.3, 8.0, 7.5, 7.0, 6.5, and 6.0) by both silver staining of the gels and binding to anti-TSH polyclonal antibodies. The distribution pattern of these forms appeared totally distinct from that of individual TSH alpha (pI 8.8, 8.4, 8.2, 7.6, 7.4, 6.8, 6.6, 5.8, and 5.4) and TSH beta (pI 8.7, 8.1, 7.2, 6.8, 6.2, and 5.8) subunits. While most anti-TSH polyclonal antibodies recognized neutral and alkaline isoforms of TSH (pI 8.6, 8.3, 8.0, 7.5, 7.0, 6.5, and 6.0) through beta determinants, they displayed a variable potency to bind acidic forms of the hormone (pI 5.8, 5.5, 4.8, and 4.5), in contrast to anti-TSH alpha antisera, which enlighted the broadest spectrum of isoforms. Monoclonal antibodies of various specificities largely reproduced this distribution, indicating that at least five distinct epitopes are coexpressed in the neutral and alkaline forms of TSH, but only two are expressed in the acidic ones. All of the forms were found to induce cAMP production and stimulate growth of FRTL-5 rat thyroid cells, although neutral forms proved to be definitely less potent than the others. We therefore, conclude that TSH isoforms differ in the expression of both their immunoreactive and bioactive domains and that the bioactive/immunoreactive ratio is not an accurate index for the biopotency of the hormone.


This article has been cited by other articles:


Home page
 Clin. Chem.Home page
S. Donadio, A. Pascual, J. H.H. Thijssen, and C. Ronin
Feasibility Study of New Calibrators for Thyroid-Stimulating Hormone (TSH) Immunoprocedures Based on Remodeling of Recombinant TSH to Mimic Glycoforms Circulating in Patients with Thyroid Disorders
Clin. Chem., February 1, 2006; 52(2): 286 - 297.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
M. W. Szkudlinski, V. Fremont, C. Ronin, and B. D. Weintraub
Thyroid-Stimulating Hormone and Thyroid-Stimulating Hormone Receptor Structure-Function Relationships
Physiol Rev, April 1, 2002; 82(2): 473 - 502.
[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 © 1991 by The Endocrine Society