FIG. 3.

Time-dependent enzymatic activity of CA130 (▴), K198βA (▪), R121βA (▾), and D286βA (•) stored at 37°C at pH 7.0. The residual enzyme activity was assayed as described previously (16). The half-lives of R121βA and K198βA increased by ca. 30 to 58% compared to wild-type CA130, however, the half-life of D286βA was decreased by about 21%. Each datum point represents mean values from five individual experiments. Similar results were obtained in each replicate.