title: Purification and characterization of two soluble acid invertase isozymes from Japanese pear fruit.
abstract: Two isozymes (AIV I and AIV II) of soluble acid invertase (EC 3.2.1.26) were purified from Japanese pear fruit through procedures including (NH(4))(2)SO(4) precipitating, DEAE-Sephacel column chromatography, Concanavalin A (ConA)-Sepharose affinity chromatography, hydroxyapatite column chromatography and Mono Q HR 5/5 column chromatography. The specific activities of purified AIV I and AIV II were 2670 and 2340 (nkat/mg protein), respectively. AIV I was a monomeric enzyme of 80 kDa, while AIV II may be also a monomeric enzyme, which is easy to be cleaved to 52 kDa and 34 kDa polypeptide during preparation by SDS-PAGE. The Km values for sucrose of AIV I and AIV II were 3.33 and 4.58 mM, respectively, and optimum pH of both enzyme activities was pH 4.5.
authors.affiliation: Laboratory of Horticultural Science, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hashizume
authors.forename: Koji
authors.initials: K
authors.lastname: Tanase
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Shiratake
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mori
authors.forename: Shohei
authors.initials: S
authors.lastname: Yamaki
mesh_terms: D011232:Chemical Precipitation; D002845:Chromatography / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D005638:Fruit / Q000201:enzymology; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D031989:Pyrus / Q000201:enzymology*; D013379:Substrate Specificity; D043324:beta-Fructofuranosidase
chemical_list: D007527:Isoenzymes; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase