Effects of partial delipidation of rat ovarian membranes on thermal stability of LH/hCG receptors

Kolena, J; Scsuková, Soňa; Tatara, M; P, Jasem

doi:10.1016/0005-2736(94)90165-1

Cited by 5 publications

(7 citation statements)

References 21 publications

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“…Aliquots of membrane-bound LHIhCG receptors were heat inactivated in water bath at constant temperature 50°C for different period of time (Kolena et al, 1994b). Adenylylcyclase activity was assayed at 30°C for 25 min with 30-40 jig plasma membrane protein (Kolena et al, 1992).…”

Section: Methodsmentioning

confidence: 99%

“…We recently demonstrated that the desensitization of LH/hCG receptors in the rat was associated with changes in the order of ovarian membrane lipids (Kolena et al, 1994a). The present paper studies structure-functional relationships of the LH/hCG receptor in the process of short-term desensitization analyzed by intrinsic fluorescence and thermal perturbation techniques in its membrane environment (Kolena et al, 1994b;1995).…”

Section: Endocrinology Anddiabetesmentioning

confidence: 99%

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Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor

Kolena

Scsuková²,

Ježová³

et al. 2009

Exp Clin Endocrinol Diabetes

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The role of the physical state of ovarian membranes was studied in the process of the early desensitization of the LH/hCG receptor. Thirty min after injection of a desensitizing dose of hCG to rats, the hCG-responsive adenylylcyclase activity was reduced, whereas hCG binding to ovarian membranes was still normal. Early desensitization decreased rigidity of membrane lipids, determined by fluorescence polarization of DPH. Possible structure-functional properties of the LH/hCG receptor were analyzed by thermal perturbation technique. Desensitization decreased thermal stability of the LH/hCG receptor in membranes and in proteoliposomes. Desensitization modified the quenching of protein fluorescence and intrinsic fluorescence spectral properties of membranes. The Stern-Volmer constants for control and desensitized membranes were found to be 4.3 and 5.5, respectively, indicating that desensitization elevated the accessibility of fluorophores for acrylamide. The changes of the physical properties of membranes resulting from desensitization was exhibited solely in the treatment with hCG in vivo, but not in vitro. The results suggest that the hCG-induced alteration of the physical state of luteal membranes may be a requirement for the induction of changes that lead to desensitization.

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Section: Methodsmentioning

confidence: 99%

Section: Endocrinology Anddiabetesmentioning

confidence: 99%

Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor

Kolena

Scsuková²,

Ježová³

et al. 2009

Exp Clin Endocrinol Diabetes

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“…Ovarian membranes were incubated at 24 8C for 30 min with arachidonic acid or BSA and washed twice with buffer A. (Kolena et al, 1994).…”

Section: Methodsmentioning

confidence: 99%

“…A sample in 5% (v/v) Tween 20 was sonicated in a MSE Ultrasonic Desintegratore. After centrifugation at 20,000g for 30 min, the pellets were washed twice with buffer A (Kolena et al, 1994).…”

Section: Methodsmentioning

confidence: 99%

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Thermal destabilization of ovarian LH/hCG receptors by negatively charged lipids

Kolena

Scsuková²,

Ježová³

2002

Exp Clin Endocrinol Diabetes

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The stabilizing effect of BSA on the rat ovarian LH/hCG receptor was analyzed by thermal perturbation technique. Thermal destabilization of the receptor with arachidonic acid along with digestion of membrane with phospholipase A2 and reversal of these effects when BSA was used as fatty acids scavenger, may indicate that free fatty acids are responsible for instability of the LH/hCG receptor. This destabilizing effect may be caused by the presence of a net negative surface charge provided by fatty acids. This presumption was corroborated by the reconstitution of delipidated LH/hCG receptor into proteoliposomes. Delipidated receptor lost to a great extent its binding activity and thermal stability. The receptor was fully reactivated by the reconstitution into proteoliposomes with neutral phosphatidylcholine but not with negatively charged phosphatidylserine and phosphatidylglycerol. Thermal inactivation of the LH/hCG receptor by delipidation was entirely inverted by treatment with phosphatidylcholine but the presence of negatively charged phospholipids did not change the heat inactivation profile of hCG-binding sites.

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Effect of phospholipids on the reconstitution and thermal stability of delipidated rat ovarian luteinizing hormone/human chorionic gonadotropin receptors in proteoliposomes

Kolena

Scsuková

Ježová

et al. 1995

Molecular and Cellular Endocrinology

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Effects of partial delipidation of rat ovarian membranes on thermal stability of LH/hCG receptors

Cited by 5 publications

References 21 publications

Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor

Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor

Thermal destabilization of ovarian LH/hCG receptors by negatively charged lipids

Effect of phospholipids on the reconstitution and thermal stability of delipidated rat ovarian luteinizing hormone/human chorionic gonadotropin receptors in proteoliposomes

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