Figure 5.

Effect of pH on activity of acid and alkaline forms I and II α-galactosidase with pNPG, raffinose, or stachyose as the substrate. The buffers used were citrate-phosphate (pH 4.0–pH 7.0), Hepes-KOH (pH 7.0–pH 8.0), and Tris (pH 8.0–pH 8.5). All data were adjusted relative to maximum activity for each enzyme. A, Raffinose was used as substrate for the acid form and alkaline form I, and stachyose was used for alkaline form II. B, pNPG as the substrate.