Figure 4.

A higher affinity for cellobiose is accompanied by a stronger glucose inhibition of β-glucosidases (BGs). (A) The values of the Michaelis constants for cellobiose hydrolysis (K_M(h)) and the inhibition constants for glucose (K_i(Glc)) are from Table 1 and Table 4, respectively. TaBG3 (◊), AtBG3 (∆) and N188BG (♦). (B and C) A literature survey revealed that BGs can be tentatively divided into three groups based on their relative affinities for cellobiose (K_M(CB)) and glucose (K_i(Glc)): (i) K_M(CB) > > K_i(Glc), BGs near the red line; (ii) K_M(CB) ≈ K_i(Glc), BGs near the pink and the green line and (iii) K_M(CB) < <K_i(Glc), BGs near the blue and the black line. For the numerical values of K_M(CB) and K_i(Glc), see Table 5. If K_i(Glc) values measured using both pNPG and cellobiose as the substrate were available, the priority was given to the K_i(Glc) value measured using cellobiose. Data from the present study (♦).