Fig. 5

Codon optimization altered protein stability upon trypsin digestion and freeze–thaw cycles. a, b Top, western blot showing 0376 (a) and 0432 (b) protein sensitivity towards trypsin digestion before and after codon optimization; bottom, densitometric analyses of the western blot results. The protein levels at time point 0 were set as 1. c Top, western blot slowing 0376 protein degradation after freeze and thaw cycles before and after codon optimization; bottom, densitometric analyses of the western blot results. The protein levels at freeze–thaw cycle 0 were set as 1. 6 × His tag antibody was used as primary antibody to detect target protein. Error bars were calculated as standard deviation of three independent experiments. *, p < 0.05; **, p < 0.01; ***, p < 0.001