Biomaterial Database

Effect of sulfhydryl reagents on PAF binding to human neutrophils and platelets. 1988

D S Ng, and K Wong

Department of Medicine, University of Alberta, Edmonton, Canada.

The effects of sulfhydryl reagents on the binding characteristics of platelet-activating factor (PAF) to PAF receptors in human neutrophils and platelets were examined. Simultaneous incubation of neutrophil or platelet membranes with radiolabeled PAF and N-ethylmaleimide (NEM), p-(chloromercuri)benzenesulfonic acid (PCMBS), or 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) resulted in a dose-dependent inhibition of PAF specific binding to the membranes. PCMBS, a membrane-impermeable compound, also inhibited PAF specific binding to intact neutrophils and platelets. In the presence of PCMBS (0.1 mM) or NEM (20 mM), the ability of PAF to displace bound [3H]PAF from neutrophil membranes was reduced. Scatchard analysis of data from saturation binding experiments using neutrophil membranes indicated that the inhibitions of PCMBS (0.1 mM) and NEM (20 mM) on PAF specific binding were due to a decrease in the receptor affinity with no significant change in the number of binding sites. The results suggest that free sulfhydryl group(s) may be associated with the agonist binding site of PAF receptors in human neutrophils and platelets.

UI	MeSH Term	Description	Entries
D009504	Neutrophils	Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.	LE Cells,Leukocytes, Polymorphonuclear,Polymorphonuclear Leukocytes,Polymorphonuclear Neutrophils,Neutrophil Band Cells,Band Cell, Neutrophil,Cell, LE,LE Cell,Leukocyte, Polymorphonuclear,Neutrophil,Neutrophil Band Cell,Neutrophil, Polymorphonuclear,Polymorphonuclear Leukocyte,Polymorphonuclear Neutrophil
D010972	Platelet Activating Factor	A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION.	AGEPC,Acetyl Glyceryl Ether Phosphorylcholine,PAF-Acether,Phosphorylcholine, Acetyl Glyceryl Ether,1-Alkyl-2-acetyl-sn-glycerophosphocholine,Platelet Aggregating Factor,Platelet Aggregation Enhancing Factor,Platelet-Activating Substance,Thrombocyte Aggregating Activity,1 Alkyl 2 acetyl sn glycerophosphocholine,Aggregating Factor, Platelet,Factor, Platelet Activating,PAF Acether,Platelet Activating Substance
D010980	Platelet Membrane Glycoproteins	Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.	PM-GP,Platelet Glycoprotein,Platelet Membrane Glycoprotein,PM-GPs,Platelet Glycoproteins,Glycoprotein, Platelet,Glycoprotein, Platelet Membrane,Glycoproteins, Platelet,Glycoproteins, Platelet Membrane,Membrane Glycoprotein, Platelet,Membrane Glycoproteins, Platelet,PM GP
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013439	Sulfhydryl Reagents	Chemical agents that react with SH groups. This is a chemically diverse group that is used for a variety of purposes. Among these are enzyme inhibition, enzyme reactivation or protection, and labelling.	SH-Reagents,Sulfhydryl Compound Antagonists,Sulfhydryl Compound Inhibitors,Thiol Reagents,Sulfhydryl Compounds Antagonists,Sulfhydryl Compounds Inhibitors,Antagonists, Sulfhydryl Compound,Antagonists, Sulfhydryl Compounds,Compound Antagonists, Sulfhydryl,Compound Inhibitors, Sulfhydryl,Inhibitors, Sulfhydryl Compound,Inhibitors, Sulfhydryl Compounds,Reagents, Sulfhydryl,Reagents, Thiol,SH Reagents
D043562	Receptors, G-Protein-Coupled	The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.	G Protein Coupled Receptor,G-Protein-Coupled Receptor,G-Protein-Coupled Receptors,G Protein Coupled Receptors,Receptor, G-Protein-Coupled,Receptors, G Protein Coupled
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In