Jintanart WongchawalitTakeshi YamamotoHiroyuki NakaiYoung Min KimNatsuko SatoMamoru NishimotoMasayuki OkuyamaHaruhide MoriOsamu SajiChanpen ChanchaoSiriwat WongsiriRudee SuraritJisnuson SvastiSeiya ChibaAtsuo KimuraHokkaido UniversityFukushima MuseumChulalongkorn UniversityMahidol University2018-08-202018-08-202006-12-01Bioscience, Biotechnology and Biochemistry. Vol.70, No.12 (2006), 2889-289813476947091684512-s2.0-33845897678https://repository.li.mahidol.ac.th/handle/20.500.14594/22940α-Glucosidase (JHGase I) was purified from a Japanese subspecies of eastern honeybee (Apis cerana japonica) as an electrophoretically homogeneous protein. Enzyme activity of the crude extract was mainly separated into two fractions (component I and II) by salting-out chromatography. JHGase I was isolated from component I by further purification procedure using CM-Toyopearl 650M and Sephacryl S-100. JHGase I was a monomeric glycoprotein (containing 15% carbohydrate), of which the molecular weight was 82,000. Enzyme displayed the highest activity at pH 5.0, and was stable up to 40°C and in a pH-range of 4.5-10.5. JHGase I showed unusual kinetic features: the negative cooperative behavior on the intrinsic reaction on cleavage of sucrose, maltose, and p-nitrophenyl α-glucoside, and the positive cooperative behavior on turanose. We isolated cDNA (1,930 bp) of JHGase I, of which the deduced amino-acid sequence (577 residues) confirmed that JHGase I was a member of α-amylase family enzymes. Western honeybees (Apis mellifera) had three α-glucosidase isoenzymes (WHGase I, II, and III), in which JHGase I was considered to correspond to WHGase I.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemistryImmunology and MicrobiologyArticleSCOPUS10.1271/bbb.60302