抗乙酰胆碱受体单抗配位特异性和序列分析

Paratope specificity and sequence analysis of monoclonal antibodies against acetylcholine receptor

测定了２株抗乙酰胆碱受体（ＡＣｈＲ）单抗的配位特异性，发现这２株抗体识别ＡＣｈＲ上同一表位。免疫印迹法证明：这２株抗体辨认ＡＣｈＲ上γ和δ亚单位。可变区核苷酸序列分析证实：这２株抗体的Ｈ链同源性为９５．３％，Ｌ链同源性为９５．８％。这２株抗体可能来源于同一前体基因，在抗原刺激的亲和成熟过程中，发生了体细胞突变。

Two monoclonal antibodies against acetylcholine receptor(AChR)were determined on their paratope specificity and nucleotide sequences of variable regions. Both antibodies inhibited each other 75%～100%for binding to AChR indicating that they recognize the same epitope.It was found that the two antibodies could specifically bind toγand δsubunits on ACHR deternmined by Western blotting.Highly homologous VH chain and VL chain sequences(95.3%and 95.8% respectively)were observed between the two antibodies.The results show that both of the antibodies could be evolved from a common precursor,and undergone somatic mutation driven by antigen-affinity maturation.