Endothelin-receptor interactions. Role of a putative sulfhydryl on the endothelin receptor.
The mechanism of action of endothelin-receptor interactions was studied, using radioligand binding assays and SDS-PAGE, to investigate the possibility of disulfide interchange. Electrophoretic analysis suggested involvement of disulfide bond(s) in the receptor-ligand complex. Treatment of Et receptors with sulfhydryl-specific alkylating reagents (NEM or others) resulted in decreased ability to bind [125I]Et-1. [Dpr1-Asp15]Et-1, an antagonist homologous to Et but with an amide link replacing one of the disulfides, bound to Et receptors reversibly, but binding of Et-1 was less reversible. Preincubation of receptors with Et-1, but not with [Dpr1-Asp15]Et-1, protected receptors from alkylation with [14C]NEM. The data suggest that the Et receptor has a sulfhydryl group at or near the Et binding site. A model is proposed in which the role of the putative sulfhydryl group is discussed.
Spinella
M J
MJ
Department of Biochemistry and Molecular Biology, Albany Medical College, NY 12208.
Kottke
R
R
Magazine
H I
HI
Healy
M S
MS
Catena
J A
JA
Wilken
P
P
Andersen
T T
TT
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004220:Disulfides / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D016232:Endothelins / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008297:Male; D011869:Radioligand Assay; D017466:Receptors, Endothelin / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013439:Sulfhydryl Reagents / Q000494:pharmacology
D004220:Disulfides; D016232:Endothelins; D017466:Receptors, Endothelin; D013438:Sulfhydryl Compounds; D013439:Sulfhydryl Reagents; C082327:endothelin 1, Dpr(1)-Asp(15)-