Ana-amylase (TVA II) from Thermoactinomyces vulgaris R-47 efficiently hydrolyzesa-1,4-glucosidic linkages of pullulan to produce panose in addition to hydrolyzing starch. TVA II also hydrolyzesa-1,4-glucosidic linkages of cyclodextrins anda-1,6-glucosidic linkages of isopanose. To clarify the basis for this wide substrate specificity of TVA II, we soaked 4 3 -a-panosylpanose (4 3 -P2) (a pullulan hydro-lysate composed of two panosyl units) into crystals of D325N inactive mutated TVA II.
