FIGURE 4.

Activity changes of WT and CBS mutants in response to AdoMet stimulation or heating. The black bars represent basal activity of WT or mutant CBS without the addition of AdoMet. The light gray bars represent CBS activity assayed in the presence of AdoMet, the allosteric activator of CBS. The dark gray bars show the response of CBS activity to gradual heating of the enzyme solution to 53 °C for 1 min prior to the enzyme assay (see “Experimental Procedures” for details). Error bars denote the S.E. values and are derived from a minimum of three independent measurements.