Pharmacological characterization of the novel helodermin/VIP receptor present in human SUP-T1 lymphoma cell membranes.
[Acetyl-His1]VIP stimulated adenylate cyclase with higher potency than VIP in membranes from human SUP-T1 lymphoblasts and was used as an efficient radioiodinated ligand with low non-specific binding to evaluate the relationship between receptor occupancy and adenylate cyclase activation and the possible interference of peptide T (an epitope derived from HIV envelope protein gp120). Various peptides inhibited [125I-acetyl-His1]VIP binding and activated the enzyme, their order of potency being: helodermin greater than [acetyl-His1]VIP greater than VIP = PHI = [Phe1]VIP greater than [D-Phe2]VIP = [D-Ala4]VIP = [D-Phe4]PHI greater than or equal to [D-Phe4]VIP greater than [D-His1]VIP giving further support for the existence of a novel subtype of helodermin/VIP receptors. [D-Ala1]peptide T and VIP-(10-28) did not recognize the binding site and did not inhibit, even at high concentration, VIP - or VIP analogue - stimulated adenylate cyclase activities.
Robberecht
P
P
Department of Biochemistry and Nutrition, Medical School, Free University of Brussels, Belgium.
De Neef
P
P
Gourlet
P
P
Cauvin
A
A
Coy
D H
DH
Christophe
J
J
D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D001665:Binding Sites; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007700:Kinetics; D008223:Lymphoma / Q000378:metabolism; D015717:Peptide T / Q000494:pharmacology; D010455:Peptides / Q000378:metabolism* / Q000494:pharmacology; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism*; D018005:Receptors, Vasoactive Intestinal Peptide; D014407:Tumor Cells, Cultured / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism* / Q000494:pharmacology
D000067956:Adenylyl Cyclase Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D011964:Receptors, Gastrointestinal Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D015717:Peptide T; D014660:Vasoactive Intestinal Peptide; C040442:heliodermin; D000262:Adenylyl Cyclases