Association/dissociation of gonadotropin subunits involves disulfide bridge disruption which is influenced by carbohydrate moiety

Colette Galet; François Lecompte; Yves Combarnous

doi:10.1016/j.bbrc.2004.09.143

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Association/dissociation of gonadotropin subunits involves disulfide bridge disruption which is influenced by carbohydrate moiety

Journal article

Peer reviewed

Association/dissociation of gonadotropin subunits involves disulfide bridge disruption which is influenced by carbohydrate moiety

Colette Galet, François Lecompte and Yves Combarnous

Biochemical and biophysical research communications, Vol.324(2), pp.868-873

11/12/2004

DOI: 10.1016/j.bbrc.2004.09.143

PMID: 15474508

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Abstract

The association and dissociation rates of pituitary porcine luteinizing hormone (pLH) and equine LH (eLH) at oxidizing potential were slow and those of equine choriogonadotropin (eCG) were even much slower. At reducing potential mimicking endoplasmic reticulum condition, association of pLH subunits was observed in less than 5 min instead of 24 h at oxidizing potential. At neutral pH and 37°C, DTNB and 2-nitro-5-thiocyanobenzoic acid (NTCB) were found to react with two cysteine residues (i.e., one S-S bridge) in pLH. The temperature dependence of the NTCB reaction on pLH was found to be similar to that of the dissociation of the hormone (T ∼ 75°C). The tight correlation between the reaction of two cysteines and dissociation of the subunits of pLH and eLH strongly suggests that transient opening of one fragile disulfide bridge is required for heterodimer assembly. Moreover, the absence of cysteine reaction with eCG indicates that its bulky carbohydrate chains exert a negative influence on the opening of this bridge leading to considerably diminished association-dissociation rates of its subunits. © 2004 Elsevier Inc. All rights reserved.

Choriogonadotropin

Disulfide bridge

Luteinizing hormone

Lutropin

Quaternary structure

Receptor binding

Structure-Activity

Details

Title: Subtitle: Association/dissociation of gonadotropin subunits involves disulfide bridge disruption which is influenced by carbohydrate moiety
Creators: Colette Galet - INRA-CNRS-Tours University, Physiol. Repro. et des Comportements, 37380 Nouzilly, France, France
François Lecompte - INRA-CNRS-Tours University, Physiol. Repro. et des Comportements, 37380 Nouzilly, France, France
Yves Combarnous - INRA-CNRS-Tours University, Physiol. Repro. et des Comportements, 37380 Nouzilly, France, France
Resource Type: Journal article
Publication Details: Biochemical and biophysical research communications, Vol.324(2), pp.868-873
DOI: 10.1016/j.bbrc.2004.09.143
PMID: 15474508
NLM abbreviation: Biochem Biophys Res Commun
ISSN: 0006-291X
eISSN: 1090-2104
Number of pages: 6
Language: English
Date published: 11/12/2004
Academic Unit: Injury Prevention Research Center; University of Iowa Health Care
Record Identifier: 9985138031002771

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