help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Purchase Article
Right arrow View Shopping Cart
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 Daja, M. M.
Right arrow Articles by Renwick, A. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Daja, M. M.
Right arrow Articles by Renwick, A. G.

Endocrinology, Vol 132, 1766-1773, Copyright © 1993 by Endocrine Society

ARTICLES

The detection and isolation of protease activity associated with purified preparations of human chorionic gonadotropin

MM Daja, J Hiyama, GK Scott and AG Renwick
Department of Biochemistry, University of Auckland, New Zealand.

The highly purified human CG (hCG) CR series is widely used as a reference material in immunological and biological assays. However these hormone preparations, specifically hCG (CR127), exhibit Arg- specific peptidase activity with synthetic peptide substrates. The putative serine protease-like activity associated with hCG (CR127) was almost completely inhibited by diisopropylfluorophosphate, soybean trypsin inhibitor, N-tosyl-L-phenylalanine chloromethyl ketone and to a lesser extent by N-alpha-p-tosyl-L-lysine chloromethyl ketone and was isolated after hydrophobic interaction and affinity chromatography with soybean trypsin inhibitor, which indicated the presence of exogenous protease contaminants rather than intrinsic peptidase activity. 3H-DFP labeling and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the isolated contaminants revealed two possible serine proteases of apparent mol wts 60,000 and 20,000. The presence of these contaminants had no apparent effect on the receptor binding capability of hCG, however the in vitro biological activity of hCG determined by maximal cAMP production, was decreased after hydrophobic interaction chromatographic purification of the hormone. These observations suggest that the serine protease-like contaminants enhance cAMP production, thereby introducing a significant source of error in biological assays that use hCG (CR127). Further purification of hCG by hydrophobic interaction and affinity chromatography is recommended before its use in bioassays or research.


This article has been cited by other articles:


Home page
 Clin. Chem.Home page
S. Birken, P. Berger, J.-M. Bidart, M. Weber, A. Bristow, R. Norman, C. Sturgeon, and U.-H. Stenman
Preparation and Characterization of New WHO Reference Reagents for Human Chorionic Gonadotropin and Metabolites
Clin. Chem., January 1, 2003; 49(1): 144 - 154.
[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 © 1993 by The Endocrine Society