Mutational analysis of the histamine H1-receptor binding pocket of histaprodifens.
Histaprodifens constitute a new class of histamine H(1)-receptor agonists. These ligands can be regarded as hybrid molecules, consisting of a histamine moiety linked at the two-position of the imidazole ring by a propyl chain to two phenyl rings, one of the characteristic features of several H(1)-receptor antagonists. To delineate the binding site of various histaprodifen-like ligands, we generated mutant histamine H(1) receptors, in which various amino acids, involved in the binding of either histamine or H(1)-receptor antagonists, were replaced by alanine. Wild-type and mutant H(1) receptors were transiently expressed in African green monkey kidney cells (COS-7) and evaluated for their interaction with histamine and various histaprodifens by [(3)H]mepyramine radioligand-binding studies and by nuclear factor kappaB (NF-kappaB) reporter-gene assays. Our data show that, within the histamine H(1)-receptor binding pocket, histaprodifens interact with both agonist and antagonist binding sites, resulting in high affinity histamine H(1)-receptor agonists.
Bruysters
Martijn
M
Leiden Amsterdam Center for Drug Research, Department of Pharmacochemistry, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands.
Pertz
Heinz H
HH
Teunissen
Aloys
A
Bakker
Remko A
RA
Gillard
Michel
M
Chatelain
Pierre
P
Schunack
Walter
W
Timmerman
Henk
H
Leurs
Rob
R
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004252:DNA Mutational Analysis; D004305:Dose-Response Relationship, Drug; D017930:Genes, Reporter / Q000235:genetics; D006632:Histamine / Q000031:analogs & derivatives* / Q000378:metabolism*; D017442:Histamine Agonists / Q000494:pharmacology*; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000235:genetics; D011738:Pyrilamine / Q000494:pharmacology; D011969:Receptors, Histamine H1 / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection
D017442:Histamine Agonists; D016328:NF-kappa B; D011969:Receptors, Histamine H1; C118994:histaprodifen; D006632:Histamine; D011738:Pyrilamine