Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 46: 1796-1803, 2000;
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (11)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jacoby, E. S.
Right arrow Articles by Iles, R. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jacoby, E. S.
Right arrow Articles by Iles, R. K.
Related Collections
Right arrow Proteomics and Protein Markers
Right arrow Endocrinology and Metabolism
(Clinical Chemistry. 2000;46:1796-1803.)
© 2000 American Association for Clinical Chemistry, Inc.

Articles

Determination of the Glycoforms of Human Chorionic Gonadotropin ß-Core Fragment by Matrix-assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Eli S. Jacoby1, Andrew T. Kicman2, Paul Laidler2 and Ray K. Iles1,a

1 The Williamson Laboratory, Department of Obstetrics and Gynaecology, St. Bartholomew’s & the Royal London School of Medicine and Dentistry, West Smithfield, London EC1A 7BE, United Kingdom.

2 The Drug Control Centre, King’s College London, Franklin-Wilkins Building, 150 Stamford St., London SE1 8WA, United Kingdom.
a Author for correspondence. Fax 44-020-7601-7050; e-mail r.k.iles{at}mds.qmw.ac.uk

Background: Metabolism of human chorionic gonadotropin (hCG) in the serum and kidney yields the terminal urinary product hCG ß-core fragment (hCGßcf), comprising two disulfide-linked peptides (ß6-ß40 and ß55-ß92) of which one (ß6-ß40) retains truncated N-linked sugars. Hyperglycosylated hCGßcf may indicate choriocarcinoma or Down syndrome, but the glycosylation profile of hCGßcf has not been thoroughly evaluated.

Methods: hCGßcf, purified from pregnancy urine, was reduced by "on-target" dithiothreitol (DTT) reduction and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass ([M+H]+) of the primary sequence of the glycosylated peptide ß6-ß40 was subtracted from the m/z values of the discrete peaks observed to give the masses of the carbohydrate moieties. Carbohydrate structure was predicted by sequentially subtracting the masses of the monosaccharide residues corresponding to N-linked carbohydrates of the hCG ß-subunit reported in the literature.

Results: Mass spectra of hCGßcf revealed a broad triple peak at m/z 8700–11300. After reduction, the triple peak was replaced by a discrete set of peaks between m/z 4156 and 6354. A peak at m/z 4156.8 corresponded to the nonglycosylated peptide (ß55-ß92). The remaining nine peaks indicated that urinary hCGßcf comprises a set of glycoforms smaller and larger than the trimannosyl core.

Conclusions: hCGßcf comprises a wider set of glycoforms than reported previously. Peaks of highest mass indicate evidence of hyperglycosylated carbohydrate moieties. The data support previous reports that hCGßcf oligosaccharides lack sialic acid and galactose residues. No indication was found of a ß6-ß40 peptide that was entirely devoid of carbohydrate.




The following articles in journals at HighWire Press have cited this article:


Home page
 GlycobiologyHome page
L. Valmu, H. Alfthan, K. Hotakainen, S. Birken, and U.-H. Stenman
Site-specific glycan analysis of human chorionic gonadotropin {beta}-subunit from malignancies and pregnancy by liquid chromatography--electrospray mass spectrometry
Glycobiology, December 1, 2006; 16(12): 1207 - 1218.
[Abstract] [Full Text] [PDF]

Home page
 Hum Reprod UpdateHome page
U.-H. Stenman, A. Tiitinen, H. Alfthan, and L. Valmu
The classification, functions and clinical use of different isoforms of HCG
Hum. Reprod. Update, November 1, 2006; 12(6): 769 - 784.
[Abstract] [Full Text] [PDF]

Home page
 GlycobiologyHome page
A. Gervais, Y.-a. Hammel, S. Pelloux, P. Lepage, G. Baer, N. Carte, O. Sorokine, J.-m. Strub, R. Koerner, E. Leize, et al.
Glycosylation of human recombinant gonadotrophins: characterization and batch-to-batch consistency
Glycobiology, March 1, 2003; 13(3): 179 - 189.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2000 by the American Association for Clinical Chemistry.