Mutagenesis of the active site of glucoamylase from Aspergillus awamori

Sierks, Michael R.

doi:10.31274/rtd-180813-12425

Cited by 2 publications

(4 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…57 On the other hand, for glucoamylase from A. awamori, the total number of subsites was reported to be seven (N m γ = 7). 58 The kinetic parameters for hydrolysis are given by the following expressions.…”

Section: Model Formulation For the Case Studymentioning

confidence: 99%

“…Since S. cerevisiae YPG/AB excretes α-amylase from B. subtilis and glucoamylase from A. awamori, in the absence of the subsite map at 303 K, the subsite affinities for α-amylase from B. subtilis at 298 K 57 and glucoamylase from A. awamori at 323 K 58 were used. Among the parameters tabulated in Table 1, 32 of them were determined by calibration using the Genetic Algorithm (GA) ("ga" subroutine) from the Genetic Algorithm and Direct Search Toolbox of MATLAB R2009b.…”

Section: Parameter Identification and Initial Conditionsmentioning

confidence: 99%

“…subtilis at 298 K and glucoamylase from A. awamori at 323 K were used. Among the parameters tabulated in Table , 32 of them were determined by calibration using the Genetic Algorithm (GA) (“ga” subroutine) from the Genetic Algorithm and Direct Search Toolbox of MATLAB R2009b.…”

Section: Parameter Identification and Initial Conditionsmentioning

confidence: 99%

See 2 more Smart Citations

Why Are Two Enzymes Better than One for the Efficient Simultaneous Saccharification and Fermentation (SSF) of Natural Polymers? Hints from Inside and Outside a Yeast

Doshi²,

Yeoh

et al. 2015

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

In the Simultaneous Saccharification and Fermentation (SSF) of natural polymers, in addition to regulating the intracellular enzymes for metabolizing the nutrients, the excretion and synthesis of extracellular depolymerases for the breakdown of the polymeric substrates must be regulated by the microbes accordingly. Through a case study of the growth of a recombinant Saccharomyces cerevisiae capable of excreting both α-amylase and glucoamylase on starch, we demonstrated that the interlinked population balance and cybernetic modeling framework developed previously, could be used to abstract and rationalize the response of the yeast in regulating these depolymerases. Our model, calibrated using the data from the literature (Ülgen et al., Process Biochem. 2002, 37, 1157–1168), showed that both α-amylase and glucoamylase are needed for efficient SSF. Specifically, by cleverly regulating the excretion of both depolymerases, yeast growth is relatively unaffected by different starches, a subtle point which could not have been elicited by existing methods.

show abstract

Section: Model Formulation For the Case Studymentioning

confidence: 99%

Section: Parameter Identification and Initial Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Why Are Two Enzymes Better than One for the Efficient Simultaneous Saccharification and Fermentation (SSF) of Natural Polymers? Hints from Inside and Outside a Yeast

Doshi²,

Yeoh

et al. 2015

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Glucoamylase exists in two forms, GAI and GAII, which differ in their ability to hydrolyze raw starch. The difference in the primary structure of the two enzymes is that of an approximately 17 kDa carboxyl-tail region, present in GAI but absent in GAII (Sierks, 1988). This region, which includes amino acids 513 to 616, is believed to be removed by limited proteolysis of GAI (Svensson et al, 1986).…”

Section: Fusions To Glucoamvlasementioning

confidence: 99%

Role of protein charge in reversed micellar extraction

Forney

View full text Add to dashboard Cite

Behavior of a series of fusion proteins of varying charge in reversed micellar extraction was studied. The proteins consisted of the enzyme glucoamylase from Aspergillus awamori joined to short peptides containing from 0-10 additional aspartate residues. The fusions were partitioned into two different cationic surfactant systems, one based on the surfactant trioctyl methyl ammonium chloride (TOMAC) and the other on cetyl trimethyl ammonium bromide (CTAB). These two systems differed chiefly in micelle size as measured by the surfactant to water ratio, WQ-Water numbers were determined for the TOMAC system, with values of approximately 10, and as a function of pH and ionic strength for CTAB for each of the mutant enzymes. For the CTAB system, water numbers were as low as 50 with NaCl concentrations of 500 mM and as high as 68 at 300 mM NaCl. The enzyme partitioned most strongly using CTAB, with maximal recoveries approaching 95%. However, in the CTAB system there were no significant differences in behavior between the mutants because of the relatively large micellar size, even under high salt concentrations. Extraction of the control enzyme from clarified cell broth indicated that broth components did not interfere with partitioning.

show abstract

Tailoring the pH dependence of glucoamylase from Aspergillus awamori by mutagenesis

Bakır

View full text Add to dashboard Cite

Properties of glucoamylase 3 Explanation of the dissertation format 13 PART I. TAILORING THE pH DEPENDENCE OF Aspergillus awamori GLUCOAMYLASE BY MUTAGENESIS 15 Research objectives 29 MATERIALS AND METHODS Genetic engineering of glucoamylase Production and purification of mutant glucoamylases Kinetic experiments RESULTS DISCUSSION CONCLUSIONS AND RECOMMENDATIONS PART II. FERMENTATIVE PRODUCTION AND HYDROLYSIS KINETICS OF Aspergillus awamori GLUCOAMYLASE INTRODUCTION 113 RESEARCH OBJECTIVES

show abstract

Mutagenesis of the active site of glucoamylase from Aspergillus awamori

Cited by 2 publications

References 17 publications

Why Are Two Enzymes Better than One for the Efficient Simultaneous Saccharification and Fermentation (SSF) of Natural Polymers? Hints from Inside and Outside a Yeast

Why Are Two Enzymes Better than One for the Efficient Simultaneous Saccharification and Fermentation (SSF) of Natural Polymers? Hints from Inside and Outside a Yeast

Role of protein charge in reversed micellar extraction

Tailoring the pH dependence of glucoamylase from Aspergillus awamori by mutagenesis

Contact Info

Product

Resources

About