(D-Ala, D-Leu) enkephalin reduces the binding of GTP in hippocampal membranes.
The effect of (D-Ala, D-Leu) enkephalin (DADLE) on the binding of GTP in hippocampal preparations was studied. It was observed that treatment of hippocampal slices with 10(-5) -5 x 10(-5) M DADLE followed by the preparation of membrane fractions reduced the binding of 35S-GTP-gamma-S. There was no change in the affinity of the binding. This decrease of 35S-GTP-gamma-S binding was reversed when 5 x 10(-5) M naltrindole was included. The effect was not observed when the membrane fractions were incubated with DADLE. Photoaffinity labeling with the use of 32P P3-(4-azidoanilido)-P1 5'-GTP followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography revealed the incorporation of radioactivity into molecular mass of the 43 kDa and 33-34 kDa proteins. 32P Photolabeling of both the 43 kDa and 33-34 kDa bands decreased following treatment of hippocampal slices with 10(-4) M DADLE. These results suggested that DADLE reduces the GDP-GTP exchange in hippocampal membranes.
Aramaki
T
T
Department of Pharmacology, Faculty of Dentistry, Osaka University, Suita, Japan.
Saito
K
K
Shinno
E
E
Ohnishi
T
T
Ooi
Y
Y
Maeda
S
S
Inoki
R
R
D000345:Affinity Labels; D000818:Animals; D001345:Autoradiography; D001386:Azides / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D016308:Enkephalin, Leucine-2-Alanine / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D009019:Morphinans / Q000494:pharmacology; D009271:Naltrexone / Q000031:analogs & derivatives*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000345:Affinity Labels; D001386:Azides; D007211:Indoles; D009019:Morphinans; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D009271:Naltrexone; C031907:GTP gamma-4-azidoanilide; D016308:Enkephalin, Leucine-2-Alanine; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; C055382:naltrindole