Effect of transmembrane Ca2+ gradient on Gs function.

G F Fan; Y G Huang; Y H Bai; F Y Yang

doi:10.1016/0014-5793(94)01307-m

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Effect of transmembrane Ca2+ gradient on Gs function.

G F Fan·Y G Huang·Y H Bai·F Y Yang

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Abstract

Gs and adenylate cyclase from bovine brain cortices were co-reconstituted into asolectin liposomes with or without 1000-fold transmembrane Ca2+ gradient. Obtained results showed that Gs activities of both binding GTP gamma S and stimulating adenylate cyclase were the highest in proteoliposomes, with a transmembrane Ca2+ gradient similar to the physiological situation and the lowest while the transmembrane Ca2+ gradient was in the inverse direction. Such a difference could be diminished following the dissipation of the transmembrane Ca2+ gradient by A23187. Time-resolved fluorescence anisotropy of diphenylhexatriene (DPH) has been used to compare the physical state of phospholipids among those proteoliposomes. It is suggested that a proper transmembrane Ca2+ gradient is essential for higher membrane fluidity, which may favor Gs function with higher GTP-binding activity and stimulation of adenylate cyclase.

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Adenylyl Cyclases Animals Calcium Cattle Cell Membrane Cerebral Cortex Fluorescence Polarization GTP-Binding Proteins Guanosine 5'-O-(3-Thiotriphosphate)Liposomes Membrane Fluidity Phosphatidylcholines Phospholipids Journal Article Research Support, Non-U.S. Gov't

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G F Fan, Y G Huang, Y H Bai, F Y Yang. 1995-01-02. Effect of transmembrane Ca2+ gradient on Gs function.. https://doi.org/10.1016/0014-5793(94)01307-m

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