Journal article
Conformational stability and in vitro bioactivity of porcine luteinizing hormone
Molecular and cellular endocrinology, Vol.176(1), pp.129-134
05/15/2001
DOI: 10.1016/S0303-7207(01)00447-6
PMID: 11369452
Abstract
Temperature-dependent dissociation of porcine luteinizing hormone (pLH) and of two of its glycoforms was studied by a combination of SDS-PAGE and micro-scale size-exclusion HPLC in parallel with the study of co-operative folding by high-sensitivity differential scanning calorimetry (HS-DSC). The transition temperature of dissociation of pLH at pH 7.0 as quantified by SDS-PAGE, HPLC and residual activity in radioreceptor assay was found to match exactly the transition temperature of its unfolding as measured by HS-DSC. Free α- and β-subunits did not exhibit any unfolding transition in the same conditions. The microcalorimetric data for two pLH isoforms exhibiting different glycosylations were identical to those of a preparation of non-separated isoforms. It is concluded that: (a) free subunits exhibit no co-operative folding (i.e. no stable three-dimensional structure) and co-operative folding occurs only in αβ heterodimers; (b) the co-operative folding is responsible for the stability of the association of subunits; and (c) the heterogeneity of carbohydrate chains does not affect the stability of folding and association of subunits. The fastening of the ‘seat-belt’ of the β-subunit embracing the α-subunit by the Cysβ26-β110 disulfide bridge had been postulated to play a role in the preservation of the dimeric structure of gonadotropins. The present work shows that dissociation of subunits is directly related to their loss of common co-operative folding.
Details
- Title: Subtitle
- Conformational stability and in vitro bioactivity of porcine luteinizing hormone
- Creators
- Tanya Burova - Institut National de la Recherche AgronomiqueFrançois Lecompte - Physiologie de la Reproduction et des ComportementsColette Galet - Physiologie de la Reproduction et des ComportementsFrançoise Monsallier - Physiologie de la Reproduction et des ComportementsSuzanne Delpech - Physiologie de la Reproduction et des ComportementsThomas Haertlé - Laboratoire d'Etude des Interactions des Molécules Alimentaires, Institut National de la Recherche Agronomique (INRA), B.P. 71627, 44316 Nantes Cedex 03, FranceYves Combarnous - Physiologie de la Reproduction et des Comportements
- Resource Type
- Journal article
- Publication Details
- Molecular and cellular endocrinology, Vol.176(1), pp.129-134
- DOI
- 10.1016/S0303-7207(01)00447-6
- PMID
- 11369452
- NLM abbreviation
- Mol Cell Endocrinol
- ISSN
- 0303-7207
- eISSN
- 1872-8057
- Publisher
- Elsevier Ireland Ltd
- Number of pages
- 6
- Language
- English
- Date published
- 05/15/2001
- Academic Unit
- Injury Prevention Research Center; University of Iowa Health Care
- Record Identifier
- 9985138031602771
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