Recognition of inter‐transmembrane regions of acetylcholine receptor α subunit by antibodies, T cells and neurotoxins implications for membrane‐subunit organization

FEBS Letters

Yokoi, Tsuyoshi¹  Manshouri, Taghi¹  Atassi, M.Zouhair¹ 

[1] Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, TX 77030, USA

关键词: Acetylcholine receptor;    Toxin binding;    Synthetic peptide;    Cobratoxin;    α-Bungarotoxin;    Antibody binding;    T-cell activation;    AChR;    the acetylcholine receptor molecule;    BGTX;    α-bungarotoxin;    CbTX;    cobratoxin;    PBS;    0.01 M sodium phosphate buffer;    pH 7.2;    in 0.15 M NaCl;    Con A;    concanavalin A;    BSA;    bovine serum albumin;   

DOI  :  10.1016/0014-5793(88)80019-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Three regions of the α chain of Torpedo californica acetylcholine receptor (AChR), corresponding to residues α262–276, α388–408 and α427–437 were synthesized, purified and characterized. The first two peptides have been proposed to occupy inter-transmembrane regions while the third represented the C-terminal segment, proposed by various models to be either extracellular or intracellular. Peptide α388–408 stimulated a good response in the AChR-primed T cells of H-2^s haplotype mice, a low response in the H-2^q haplotype and no response in the H-2^b haplotype. Peptide α427–437 stimulated AChR-primed T cells of the H-2^s haplotype, but caused no response in the q and b haplotypes. Peptide α262–276 evoked no in vitro stimulation in any of the s, q or b haplotypes. In antibody binding studies, peptide α388–408 bound antibodies raised against free AChR or against membrane-bound AChR. The other two peptides showed little or no binding activity. Further, peptide α388–408 bound specifically both ¹²⁵-I-labelled bungarotoxin and cobratoxin, while the other two peptides had no binding activity. These results were consistent with only one of the models for subunit organization with-in the membrane.

【 授权许可】

Unknown