Isolation of Crystalline Taka-Amylase a From “Takadiastase Sankyo”

Akabori, Shirô; Ikenaka, Tokuji; Hagihara, Bunji

doi:10.1093/oxfordjournals.jbchem.a126475

Cited by 63 publications

(19 citation statements)

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“…2A. The structure consists of three domains: a central main domain, A (residues 1–121 and 177–380), formed by an N-terminal catalytic (β/α) 8 -barrel; a small β-pleated domain, B (122–176), protruding between β3 and α3; and a C-terminal globular domain, C (residues 381–478), consisting of a β-structure with a Greek-key motif [26]–[32]. This structure is similar to previously reported X-ray structures of Ao α-amylase.…”

Section: Resultsmentioning

confidence: 99%

Effect of Heavy Atoms on the Thermal Stability of α-Amylase from Aspergillus oryzae

Sugahara

Takehira

2013

PLoS ONE

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Currently, there are no versatile and established methods for improving stability of proteins. In an entirely different approach from conventional techniques such as mutagenesis, we attempted to enhance enzyme stability of α-amylase from Aspergillus oryzae using a heavy-atom derivatization technique. We evaluated changes in stability using differential scanning calorimetry (DSC). Candidate heavy atoms were identified using the Heavy-Atom Database System HATODAS, a Web-based tool designed to assist in heavy-atom derivatization of proteins for X-ray crystallography. The denaturation temperature of α-amylase derivatized with gadolinium (Gd) or samarium (Sm) ions increased by 6.2 or 5.7°C, respectively, compared to that of the native protein (60.6°C). The binding of six Gd ions was confirmed by X-ray crystallography of the enzyme at 1.5 Å resolution. DSC and dynamic light-scattering data revealed a correlation between stability and the aggregation state upon addition of Gd ions. These results show that HATODAS search is an effective tool for selecting heavy atoms for stabilization of this protein.

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Section: Resultsmentioning

confidence: 99%

Effect of Heavy Atoms on the Thermal Stability of α-Amylase from Aspergillus oryzae

Sugahara

Takehira

2013

PLoS ONE

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“…Two kinds of acid stable α-amylase from Aspergillus kawachii have been reported (Mikami et al, 1987). There has also been reported an acid-stable and an unstable α-amylase from Aspergillus niger (Arai et al, 1968), crystals of Aspergillus oryzae enzyme (Fischer and Montmollin, 1951;Akabori et al, 1954), and some properties of A. awamori α-amylase (Bhella and Altosaar, 1984). A. awamori produces several potent amylolytic enzymes for bioindustry, and the mold also produces three forms of α-glucosidases (Yamazaki et al, 1977) and two types of glucoamylases.…”

Section: Introductionmentioning

confidence: 99%

Degradation of Raw Starch Granules by α-Amylase Purified from Culture of Aspergillus awamori KT-11

Matsubara¹,

Ammar²,

Anindyawati³

et al. 2004

BMB Reports

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Raw-starch-digesting α-amylase (Amyl III) was purified to an electrophoretically pure state from the extract of a koji culture of Aspergillus awamori KT-11 using wheat bran in the medium. The purified Amyl III digested not only soluble starch but also raw corn starch. The major products from the raw starch using Amyl III were maltotriose and maltose, although a small amount of glucose was produced. Amyl III acted on all raw starch granules that it has been tested on. However, it was considered that the action mode of the Amyl III on starch granules was different from that of glucoamylase judging from the observation of granules under a scanning electron microscope before and after enzyme reaction, and also from the reaction products. Glucoamylase (GA I) was also isolated and it was purified to an electrophoretically pure state from the extract. It was found that the electron micrographic features of the granules after treatment with the enzymes were quite different. A synergistic effect of Amyl III and GA I was observed for the digestion of raw starch granules.

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“…Two main types of fungal α-amylases are typically used in industrial applications: the common neutral types (such as Taka-amylase from Aspergillus oryzae [5] or the Taka-amylase-like enzyme (amyA/amyB) from Aspergillus niger [6] and the acid-stable types from A. niger [7], Aspergillus kawachi [8] and Rhizomucor pusillus [9]). …”

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confidence: 99%

Gene Cloning, Heterologous Expression, and Characterization of a High Maltose-Producing α-Amylase of Rhizopus oryzae

Song

Zuo

Niu

et al. 2011

Appl Biochem Biotechnol

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A putative α-amylase gene, designated as RoAmy, was cloned from Rhizopus oryzae. The deduced amino acid sequence showed the highest (42.8%) similarity to the α-amylase from Trichoderma viride. The RoAmy gene was successfully expressed in Pichia pastoris GS115 under the induction of methanol. The molecular weight of the purified RoAmy determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis was approximately 48 kDa. The optimal pH and temperature were 4-6 and 60 °C, respectively. The enzyme was stable at pH ranges of 4.5-6.5 and temperatures below 50 °C. Purified RoAmy had a K(m) and V(max) of 0.27 mg/ml and 0.068 mg/min, respectively, with a specific activity of 1,123 U/mg on soluble starch. Amylase activity was strongly inhibited by 5 mM Cu(2+) and 5 mM Fe(2+), whereas 5 mM Ca(2+) showed no significant effect. The RoAmy hydrolytic activity was the highest on wheat starch but showed only 55% activity on amylopectin relative to soluble corn starch, while the pullulanase activity was negligible. The main end products of the polysaccharides tested were glucose and maltose. Maltose reached a concentration of 74% (w/w) with potato starch as the substrate. The enzyme had an extremely high affinity (K(m) = 0.22 mM) to maltotriose. A high ratio of glucose/maltose of 1:4 was obtained when maltotriose was used at an initial concentration of 40 mM.

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Isolation of Crystalline Taka-Amylase a From “Takadiastase Sankyo”

Cited by 63 publications

References 0 publications

Effect of Heavy Atoms on the Thermal Stability of α-Amylase from Aspergillus oryzae

Effect of Heavy Atoms on the Thermal Stability of α-Amylase from Aspergillus oryzae

Degradation of Raw Starch Granules by α-Amylase Purified from Culture of Aspergillus awamori KT-11

Gene Cloning, Heterologous Expression, and Characterization of a High Maltose-Producing α-Amylase of Rhizopus oryzae

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