Arginine and cysteine residues in the ligand binding site of alpha 2-adrenergic receptors.
alpha 2-Adrenergic receptors were identified in calf brain, human platelet and human uterus membranes by [3H]-rauwolscine binding. The reagents phenylglyoxal (selective for guanidino groups), p- hydroxy mercuribenzoate and N-ethylmaleimide (selective for sulfhydryl groups) caused a time- and dose- dependent decrease in the number of receptor sites. alpha 2-Adrenergic agonists and antagonists mediated efficient protection of the receptors against these reagents. These data suggest that essential arginine and cysteine residues are present at or near the alpha 2-adrenergic binding site.
Mattens
E
E
Bottari
S
S
Vokaer
A
A
Vauquelin
G
G
D000818:Animals; D001120:Arginine; D001665:Binding Sites; D001792:Blood Platelets; D001923:Brain Chemistry; D002417:Cattle; D003545:Cysteine; D004837:Epinephrine / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism; D013439:Sulfhydryl Reagents; D014599:Uterus; D015016:Yohimbine / Q000378:metabolism*
D011942:Receptors, Adrenergic, alpha; D013439:Sulfhydryl Reagents; D015016:Yohimbine; D001120:Arginine; D003545:Cysteine; D004837:Epinephrine