Binding of (/sup 3/H)forskolin to solubilized preparations of adenylate cyclase
The binding of (/sup 3/H)forskolin to proteins solubilized from bovine brain membranes was studied by precipitating proteins with polyethylene glycol and separating (/sup 3/H)forskolin bound to protein from free (/sup 3/H)forskolin by rapid filtration. The K/sub d/ for (/sup 3/H)forskolin binding to solubilized proteins was 14 nM which was similar to that for (/sup 3/H)forskolin binding sites in membranes from rat brain and human platelets. Forskolin analogs competed for (/sup 3/H)forskolin binding sites with the same rank potency in both brain membranes and in proteins solubilized from brain membranes. (/sup 3/H)forskolin bound to proteins solubilized from membranes with a Bmax of 38 fmolmg protein which increased to 94 fmolmg protein when GppNHp was included in the binding assay. In contrast, GppNHp had no effect on (/sup 3/H)forskolin binding to proteins solubilized from membranes preactivated with GppNHp. Solubilized adenylate cyclase from non-preactivated membranes had a basal activity of 130 pmolmgmin which was increased 7-fold by GppNHp. In contrast, adenylate cyclase from preactivated membranes had a basal activity of 850 pmolmgmin which was not stimulated by GppNHp or forskolin
- Research Organization:
- Food and Drug Administration, Bethesda, MD (USA)
- OSTI ID:
- 5281705
- Journal Information:
- Life Sci.; (United States), Vol. 42:14
- Country of Publication:
- United States
- Language:
- English
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CYCLASES
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RECEPTORS
BLOOD PLATELETS
BRAIN
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RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
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LABELLED COMPOUNDS
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ORGANIC COMPOUNDS
ORGANS
PRIMATES
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550201* - Biochemistry- Tracer Techniques