Binding of (/sup 3/H)forskolin to solubilized preparations of adenylate cyclase

Journal Article · Fri Jan 01 00:00:00 EST 1988 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(88)90167-1· OSTI ID:5281705

Nelson, C A; Seamon, K B

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

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CYCLASES
ENZYME ACTIVITY
PROTEINS
BIOCHEMICAL REACTION KINETICS
RECEPTORS
BLOOD PLATELETS
BRAIN
CELL MEMBRANES
MAN
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
ENZYMES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LYASES
MAMMALS
MATERIALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PRIMATES
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques