Glucoamylase Activity

Calculations One unit of glucoamylase activity is defined as the amount of glucoamylase that will liberate 0.1 xmol/ min of / -niirophcnol from the PNPG Solution under the conditions of the assay. 

Catalase Activity, 791 Cellulose Activity, 791 Chymotrypsin Activity, 793 Diastase Activity (Diastic Power), 793 a-Galactosidase Activity, 794 [i-Glucanasc Activity, 795 Glucoamylase Activity... 

Y. Nakamura, F. Kobayashi, M. Ohnaga and T. Sawada. 1997. Alcohol Fermentation of Starch by a Genetic Recombinant Yeast Having Glucoamylase Activity. Biotechnology and Bioengineering, 53, 21-25. 

The solubilized granule-bound enzymes showed A/, values for ADP-Glc about 10-fold lower than that measured before solubilization (0.96 mmol U for the intact granule activity unpublished results). The granule-bound enzyme is also active with UDP-Glc with 1 mmol 1 UDP-Glc having about 7% of the activity rate seen with 1 mmol ADP-Glc. If the concentration of UDP-Glc is raised to 20 mmol then the rate of activity is about 73% of that of ADP-Glc. Upon solubilization with a-amylase and glucoamylase, activity with... 

Table VII. Retention of Glucoamylase Activity in Liquid Solutions after 21 Days...

In our own laboratory an efficient method for removal of traces of transglucosylase was developed involving use of a column of cation exchange resin (5). Typical laboratory results are shown in Table IX. The data show essentially no loss of glucoamylase activity with removal of the transglucosylase by the ion exchange treatment. Plant scale-up of the process gave no particular difficulties. 

Fig. 27.6. Glucoamylase activity. Glucoamy-lase is an a-1,4 exoglycosidase, which initiates cleavage at the nonreducing end of the sugar. Thus, for malotriose, the bond labeled 1 will be hydrolyzed first, which frees up the bond at position 2 to be the next one hydrolyzed.

In a study of the glucoamylase activity produced by Endomycopsis bispora the dependence of secretion of the enzyme upon morphology was examined. ... 

Porcine-spleen acid a-D-glucosidase has been shown to possess glucoamylase activity. 

The properties of a glucoamylase activity isolated from cultures of Corticium rolfsii growing in the presence of sucrose have been investigated. The enzyme is stable to acid. 

Active immobilized enzyme heat-transfer study of packed reactors incorporating immobilized glucoamylase Active immobilized enzyme... 

The separation by polyacrylamide gel electrophoresis and subsequent analysis of the components of guinea pig intestinal brush border membrane revealed the presence of inter alia enzyme complexes , a-D-glucosidase-glucoamylase, a-D-glucosidase-sucrose, and a-D-glucohydrolase-glucoamylase. Glucoamylase activity has been solubilized from rat intestinal mucosa (see p. 406). ... 

An assay of glucoamylase activity in microbial materials is based on the determination of o-glucose released from soluble starch by means of the d-glucose oxidase-peroxidase reagent. The method is simple, reproducible (standard deviation 2%), and unaffected by the presence of a-amylase. 

The levels of glucoamylase activity in jejunal biopsy specimens from patients with a deficiency of sucrose a-D-glucohydrolase-oligo-l,6-D-glucosidase ( sucrase-isomaltase ) have been determined. ... 

The action of a mixture of mould enzymes containing glucoamylase activity on 6-amino-6-deoxyamyloses has been studied. ... 

The properties of glucoamylase activities occurring in a number of strains of Klebsiella (Aerobacter) aerogenes and Rhizopus species have been investigated. 

A neutral a-D-galactosidase from porcine serum has been purified by repeated ion-exchange chromatography and gel filtration. The purified enzyme ( S ao.w 10.7 S, p7 4.0, mol. wt. 2.7 x 10 in the presence of sodium dodecyl sulphate) was most active against maltose and soluble starch in the pH range 6—7 and also possessed glucoamylase activity. 

An acid a-D-glucosidase in human liver has been purified by adsorption onto Sephadex, followed by desorption with methyl a-D-glucopyranoside, a competitive inhibitor.The enzyme (p/4.58) was shown to be homogeneous by ultracentrifugation and disc gel electrophoresis. Guanidinium hydrochloride, but not urea, dissociated the enzyme. The glucoamylase activity, but not the maltase activity, was inhibited by methyl a-D-glucopyranoside. 

An acid a-D-glucosidase activity isolated from human liver exhibits glucoamylase activity, which was competitively inhibited by methyl a-D-glucopyranoside, and maltase activity. ... 

Porcine-serum a-D-glucosidase exhibits glucoamylase activity. A simple procedure for isolating the glucoamylase-maltase complex from rabbit intestines by affinity chromatography on Sephadex G-200 has been reported. Other Sephadex gels did not bind the enzyme to any significant extent. 

Fumaric add production can be increased by using the well-known producer Rhizopus strain, possessing high glucoamylase activity and maintaining conditions for mycelia growth for increased fumaric acid production af a reduced fermentation time. 

---