title: Lectin-induced inhibition of nerve growth factor binding by receptors of sympathetic ganglia.
abstract: Nerve growth factor (NGF) initiates a pleiotypic response in numerous tissues derived from the neural crest by binding to specific plasma membrane receptors. In sympathetic ganglia this receptor has been characterized as a highly asymmetric, minimally hydrophobic, intrinsic membrane protein with a molecular weight of 135,000 (Costrini et al., 1979b). To further characterize this moiety we assessed the effects of lectins on 125I-NGF specific binding to preparations of particulate and nonionic detergent-extracted microsomal receptors of rabbit superior cervical ganglia (SCG). Concanavalin A (Con A) and wheat germ agglutinin (WGA), but not soybean agglutinin or Ulex europaeus 1, induced a concentration-related, carbohydrate-specific decrease in 125I-NGF binding. Following Con A exposure, 125I-NGF specific decrease in 125I-NGF binding. Following Con A exposure, 125I-NGF specific binding to particulate SCG receptors was maximally reduced to 23% of control values. WGA similarly reduced NGF binding to particulate microsomal receptors to 37% of control values. Scatchard analysis of growth factor binding following Con A exposure indicated that this lectin effect was principally due to a sixfold reduction in maximum receptor affinity. Lectin-associated impairment of NGF binding was also demonstrated by using a Triton X-100 solubilized receptor preparation. These results provide evidence that the high-affinity-state NGF receptor of SCG is a glycoprotein containing N-acetylglucosamine and alpha-D-mannopyranoside residues. These residues are probably located in close proximity to the growth factor binding region of the NGF receptor.
mesh_terms: D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D005728:Ganglia, Sympathetic / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D037102:Lectins / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009414:Nerve Growth Factors / Q000378:metabolism*; D017830:Octoxynol; D011092:Polyethylene Glycols; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017475:Receptors, Nerve Growth Factor; D014909:Wheat Germ Agglutinins
chemical_list: D037102:Lectins; D009414:Nerve Growth Factors; D011956:Receptors, Cell Surface; D017475:Receptors, Nerve Growth Factor; D014909:Wheat Germ Agglutinins; D003208:Concanavalin A; D011092:Polyethylene Glycols; D017830:Octoxynol