Presence of various carbohydrate moieties including beta-galactose and N-acetylglucosamine residues on solubilized porcine brain neurokinin-1/substance P receptors.
Neurokinin-1 (NK-1)/substance P (SP) receptors were solubilized using 10 mM 3-[( cholamidopropyl)-dimethylammonio]-1- propanesulfate from porcine striatal membranes (solubilization yield, 80%). In solubilized preparations, [3H]SP apparently bound to a single class of high-affinity sites (KD = 0.82 +/- 0.13 nM) as in membrane homogenates. The ligand selectivity pattern observed in both membrane and solubilized receptor preparations indicated that [Sar9,Met(O2)11]SP = SP much greater than senktide = [Nle10]neurokinin A. This suggests the selective labeling of the NK-1 receptor class in both assays. Solubilized receptors were retained on agarose-coupled lectins that bind N-acetylglucosamine-galactose and beta-galactose (Ricinus communis I and Ricinus communis II), mannose (concanavalin A and lentil), and N-acetylglucosamine (wheat germ agglutinin) but not on lectins binding fucose (Lotus A) and N-acetylgalactosamine (Doli-chos biflorus A). Thus, it appears that porcine brain NK-1/SP receptors are enriched with various carbohydrate moieties, beta-galactose and N-acetylglucosamine-galactose residues being especially abundant. This situation is rather different from that in various other members of the rhodopsin seven-transmembrane receptor superfamily.
Liu
Y F
YF
Department of Psychiatry, McGill University, Verdun, Quebec, Canada.
Quirion
R
R
D000117:Acetylglucosamine / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002241:Carbohydrates / Q000032:analysis / Q000494:pharmacology*; D002793:Cholic Acids / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D005690:Galactose / Q000494:pharmacology*; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D012995:Solubility; D013552:Swine
D002241:Carbohydrates; D002793:Cholic Acids; D003902:Detergents; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; C028213:3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate; D000117:Acetylglucosamine; D005690:Galactose