FIGURE 3.

Activity of alanine substitution mutants of the AgG3z8 protein. A–I, 1st to 7th amino acids of the z8 peptide in AgG3z8 replaced with alanine by site-directed mutagenesis. The AChR clustering activities of the wild-type AgG3z8 and each of the mutant proteins at 1 μg/ml were measured in C2C12 myotube culture. J, statistic analysis of the degrees of AChR clustering. The data represent the mean ± S.E. (error bars) of results from four separate experiments. **, p < 0.01 compared with AgG3z8.