The detergent Solulan C-24 reveals properties of the olfactory adenylate cyclase system.
The detergent Solulan C-24 has been shown to activate the olfactory adenylate cyclase, with loss of the odorant modulation, at concentrations too low to cause significant solubilization. The activation is synergistic with that of nonhydrolysable GTP analogues, forskolin and AlF4-. These effects are not reversible. Solulan causes the cyclase activity to become subject to ATP inhibition, which is competitively relieved by GTP gamma S, and increases the GTP gamma S concentration required for half-maximal stimulation of the system. This suggests a change in the GTP-binding site of the stimulatory G-protein. Activation by GTP gamma S, without Solulan, indicates that the cyclase catalytic unit, rather than the available G-protein, may be limiting in the system. We suggest that Solulan may remove an inhibitory control on the cyclase activity.
Robinson
C J
CJ
Department of Chemistry, University of Warwick, Coventry, U.K.
Shirley
S G
SG
Dodd
G H
GH
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D003902:Detergents / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D009831:Olfactory Mucosa / Q000187:drug effects / Q000201:enzymology*; D011092:Polyethylene Glycols / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013501:Surface-Active Agents / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology
D003902:Detergents; D013501:Surface-Active Agents; D013873:Thionucleotides; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D011092:Polyethylene Glycols; C032895:polyoxyethylene-24-cholesteryl ether; D006160:Guanosine Triphosphate; D000262:Adenylyl Cyclases