Species- and subtype-specific recognition by antibody WF6 of a sequence segment forming an alpha-bungarotoxin binding site on the nicotinic acetylcholine receptor alpha subunit.
The monoclonal antibody WF6 competes with acetylcholine and alpha-bungarotoxin (alpha-BGT) for binding to the Torpedo nicotinic acetylcholine receptor (nAChR) alpha 1 subunit. Using synthetic peptides corresponding to the complete Torpedo nAChR alpha 1 subunit, we previously mapped a continuous epitope recognized by WF6, and the prototope for alpha-BGT, to the sequence segment alpha 1(181-200). Single amino acid substitution analogs have been used as an initial approach to determine the critical amino acids for WF6 and alpha-BGT binding. In the present study, we continue our analysis of the structural features of the WF6 epitope by comparing its cross-reactivity with synthetic peptides corresponding to the alpha 1 subunits from the muscle nAChRs of different species, the rat brain alpha 2, alpha 3, alpha 4 and alpha 5 nAChR subtypes, and the chick brain alpha-BGT binding protein subunits, alpha BGTBP alpha 1 and alpha BGTBP alpha 2. Our results indicate that WF6 is able to cross-react with the muscle alpha 1 subunits of different species by virtue of conservation of several critical amino acid residues between positions 190-198 of the alpha 1 subunit. These studies further define the essential structural features of the sequence segment alpha 1(181-200) required to form the epitope for WF6.
McLane
K E
KE
Department of Biochemistry, College of Biological Sciences, University of Minnesota St. Paul 55108.
Fritzen
M
M
Wu
X
X
Diethelm
B
B
Maelicke
A
A
Conti-Tronconi
B M
BM
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology; D002038:Bungarotoxins; D002417:Cattle; D003429:Cross Reactions / Q000276:immunology; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009132:Muscles / Q000276:immunology*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D011898:Ranidae; D051381:Rats; D011950:Receptors, Cholinergic / Q000276:immunology*; D011978:Receptors, Nicotinic / Q000276:immunology*; D012689:Sequence Homology, Nucleic Acid; D012911:Snakes; D013045:Species Specificity; D014101:Torpedo; D064569:alpha7 Nicotinic Acetylcholine Receptor
D000911:Antibodies, Monoclonal; D002038:Bungarotoxins; C579167:Chrna7 protein, human; C579166:Chrna7 protein, mouse; C579165:Chrna7 protein, rat; D010455:Peptides; D011950:Receptors, Cholinergic; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor