FIGURE 2.

Biochemical activities on α-1,6- and α-1,4-glucosidic substrates. The α-glucosidase activity on different α-glucosidic substrates was assayed on crude extract from JF1811 yeast strain overexpressing MAL12 or ORFs of this gene family. ★, because IMA3 and IMA4 are 100% identical, they could not be differentiated. The cells were grown in YN synthetic medium containing 2% glucose to A_{600 nm} ∼ 1.0, and activities were measured using 20 A_{600 nm} units of cells. Control: JF1811 strain transformed with the empty YEplac181-PGK/CYC1 plasmid. The α-p-nitrophenyl α-d-glucopyranoside (pNPG) was used to measure total α-glucosidase activity. Maltose and maltotriose were used to measure maltase activity. αMG and isomaltose were used to measure isomaltase activity. Activities and standard deviation were calculated from three independent cultures.