Preparation and Some Properties of Active Monomer of Sweet Potatoβ-Amylase

Autor: Yong-Geun Ann, Masaru Iizuka, Takehiko Yamamoto, Noshi Minamiura
Rok vydání: 1990
Předmět:
Zdroj: Agricultural and Biological Chemistry. 54:769-774
ISSN: 0002-1369
DOI: 10.1080/00021369.1990.10870013
Popis: Sweet potato β-amylase was divided into two active fractions (named F-A and F-B) by modification with periodate-oxidized maltohexaose at pH 9.7. F-A and F-B isolated by exclusion chromatography using Sephadex G-200 corresponded to a pentamer of the enzyme with molecular weight of 31.5 × 104 and a monomer with molecular weight of 6.4 × 104, respectively. The contents of carbohydrate of the modified enzymes were 9.7% for F-A and 9.3% for F-B. The specific activities of F-A and F-B were 2,059 and 1,129 units/mg of protein and were reduced to 82% and 45% of that of the original enzyme, respectively. The modification of the enzyme with the oxidized maltohexaose was due to formation of a Schiff base between e-NH2 groups of lysines of the enzyme protein and CHO groups of the oxidized maltohexaose.
Databáze: OpenAIRE