Figure 5.
Effect of BSA on EfHTG activities (XET, MXE, CXE).
(a) Effect of increasing BSA concentrations on CXE activity expressed as a percentage of the activity obtained in the presence of the previously used routing BSA concentration (0.1% (w/v)). Donor substrate: untreated or NaOH‐pre‐treated filter paper. Acceptor substrate: [3H]XXXGol. Enzyme: Pichia‐produced EfHTG. n = 3; data points are shown as circles.
(b) Analogous to the experiment in (a), but testing the effect of increasing BSA concentrations on XET and MXE activities with soluble donor substrates; n = 3; data points are shown as rhombi (MXE) and triangles (XET).
(c) Recovery of EfHTG bound to cellulose I and II of paper or cotton wool. Pichia‐produced EfHTG was applied onto cellulose (untreated or NaOH‐pre‐treated) in presence of increasing BSA concentrations (0–10%), which was incubated under humid conditions with no acceptor substrate; after 16 h, the cellulose was then washed in buffer to release unbound EfHTG, which was then assayed for its MXE activity with [3H]XXXGol as acceptor substrate. The proportion of EfHTG (%) recovered in the presence of increasing BSA concentrations is expressed as solubilised MXE activity; 100% MXE activity was produced by EfHTG which had not been applied onto paper; n = 3; data points are shown as circles (paper) and squares (cotton wool).
Paper, Whatman No. 1 filter paper; cellulose I, plain paper or cotton wool; cellulose II, alkali‐pre‐treated paper or cotton wool.