5090-06-2Relevant academic research and scientific papers
Subsite Structure of Chalara paradoxa Glucoamylase and Interaction of the Glucoamylase with Cyclodextrins
Monma, Mitsuru,Yamamoto, Yoshihiro,Kainuma, Keiji
, p. 1503 - 1508 (2007/10/02)
The action of Chalara paradoxa glucoamylase (raw-starch-digesting enzyme) was studied with linear and cyclic maltodextrins.Subsite affinities (Ai) of the amylase were evaluated by the subsite theory.The active site was considered to be made up of seven subsites: A1 = 0.05 kcal/mol, A2 = 4.99 kcal/mol, A3 = 1.30 kcal/mol, A4 = 0.77 kcal/mol, A5 = 0.33 kcal/mol, A6 = 0.21 kcal/mol and A7 = 0.21 kcal/mol.Inhibitions by alpha-, beta-, and gamma-cyclodextrins were competitive for starch digestion by C. paradoxa glucoamylase.The inhibitor constants (Ki) of α-, β-, and γ-cyclodextrin for the amylase were 8.9, 1.4, and 3.9 mM, respectively.The Michaelis constant (Km) of 6-O-α-maltosyl-α-cyclodextrin digestion was 0.79 mM for the amylase.
ELECTROCHEMICAL DETECTION OF REDUCING CARBOHYDRATES PRODUCED BY THE TRANSFERASE ACTION OF YEAST DEBRANCHING ENZYME ON MALTOSACCHARIDES
Tabata, Shiro,Ide, Takeshi
, p. 245 - 252 (2007/10/02)
A sensitive method for the detection of maltosaccharides up to maltoheptaose is based on an electrochemical detector using bis(1,10-phenanthroline)-copper(II) in the post column reaction after h.p.l.c. on an amino-bonded column.This method has been used for the analysis of the maltosyl and maltotriosyl transferase action of the yeast debranching enzyme with maltosaccharides as the substrates.The smallest donor substrate for maltosyl transfer was maltotetraose, and maltopentaose, maltohexaose, and maltoheptaose were donor substrates for both maltosyl and maltotriosyl transfers.Maltosyl residues were transferred in preference to maltotriosyl residues from maltopentaose, but maltotriosyl residues were transferred prefentially from maltohexaose and maltoheptaose.Maltotriose is an acceptor but not a donor of maltosyl and maltotriosyl transfers.
