FIG. 2.

Further purification of β-lactamase from M. tuberculosis H37Ra by chromatofocusing. Fractions with β-lactamase activity and a relatively low albumin concentration from gel filtration chromatography (e.g., fractions 29 to 36, Fig. 1) were pooled, concentrated, and loaded onto a Mono P column. The proteins were eluted in a linear pH gradient as 2-ml fractions. The β-lactamase activity of each fraction is plotted. Three peaks of β-lactamase activity were identified.