Enzymatic Determination of Structure of Singly Branched Hexaose Dextrins Formed by Liquefying αAmylase of Bacillus subtilis

Umeki, Kimio; Yamamoto, Takehiko

doi:10.1093/oxfordjournals.jbchem.a129874

Cited by 31 publications

(14 citation statements)

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“…As a branched DP 4 fraction, 62-O-ot-maltosyl-maltose and 62-O-a-glucosyl-maltotriose were produced (7) and could be separated by paper chromatography. The former migrated more slowly than did the latter (16).…”

Section: Methodsmentioning

confidence: 80%

“…The products were analyzed by preparative-scale paper chromatography, and the smallest limit dextrin was extracted as 63-O-a-glucosylmaltotriose (16 After an appropriate incubation period at 50°C, 50-,ul samples were collected, and the reaction was stopped by heat treatment at 100°C for 5 min. A 10-,Il amount of each sample was applied to chromatography paper.…”

Section: Methodsmentioning

confidence: 99%

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Pattern of action of Bacillus stearothermophilus neopullulanase on pullulan

Imanaka

Kuriki

1989

J Bacteriol

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The action of neopullulanase from Bacillus stearothermophilus on many oligosaccharides was tested. The enzyme hydrolyzed not only a-(1-+4)-glucosidic linkages but also specific a-(1-+6)-glucosidic linkages of several branched oligosaccharides. When pullulan was used as a substrate, panose, maltose, and glucose, in that order, were produced as final products at a final molar ratio of 3:1:1. According to these results, we proposed a model for the pattern of action of neopullulanase on puliulan as follows. In the first step, the enzyme hydrolyzes only a-(1-)4)-glucosidic linkages on the nonreducing side of a-(1->6) linkages of puliulan and produces panose and several intermediate products composed of some panose units. In the second step, taking 62-0-a-(63-0-a-glucosyl-maltotriosyl)-maltose as an example of one of the intermediate products, the enzyme hydrolyzes either a-(1-,4) (the same position as that described above) or a-(1-6) linkages and produces panose or 63-_-a-glucosyl-maltotriose plus maltose, respectively. In the third step, the a-(1-4) linkage of 63-0-aL-glucosyl-maltotriose is hydrolyzed by the enzyme, and glucose and another panose are produced. To confirm the model of the pattern of action, we extracted intermediate products produced from pullulan by neopullulanase and analyzed the structures by glucoamylase, pullulanase, and neopullulanase analyses. The experimental results supported the above-mentioned model of the pattern of action of neopullulanase on pullulan.Four types of pullulan-hydrolyzing enzymes have been reported: (i) glucoamylase (glucan 1,4-a-glucosidase; EC 3.2.1.3) (15), which hydrolyzes pullulan from nonreducing ends to produce glucose; (ii) pullulanase (ax-dextrin endo-1,6-a-glucosidase; EC 3.2.1.41) (2), from Klebsiella pneumoniae, which hydrolyzes a-(1-+6)-glucosidic linkages of pullulan to produce maltotriose; (iii) isopullulanase (EC 3.2.1.57) (13), from Aspergillus niger, which hydrolyzes ot-(1-4)-glucosidic linkages of pullulan to produce isc panose (6-0-amaltosyl-glucose); and (iv) neopullulanase, which hydrolyzes a-(1-+4)-glucosidic linkages of pullulan to produce panose (62-O-a-glucosyl-maltose). The last enzyme was reported to be a new type of pullulanase from Bacillus stearothermophilus TRS40 in our previous paper (8).Neopullulanase from B. stearothermophilus TRS40 could hydrolyze pullulan efficiently and only hydrolyzed a small amount of starch. When pullulan was used as a substrate, the main product was panose, and small amounts of glucose and maltose were simultaneously produced (8). Therefore, neopullulanase was obviously different from the pullulan-hydrolyzing enzymes previously reported (2, 13-15) and should be considered as a new enzyme (8).To produce glucose and maltose in addition to panose from pullulan, neopullulanase has to hydrolyze a-(1-+6)-glucosidic linkages as well as a-(1--+4)-glucosidic linkages. The present investigation was conducted to reveal the attack point of glucosidic linkages of pullulan by neopullulanase. This paper describes the action of ne...

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Section: Methodsmentioning

confidence: 80%

Section: Methodsmentioning

confidence: 99%

Pattern of action of Bacillus stearothermophilus neopullulanase on pullulan

Imanaka

Kuriki

1989

J Bacteriol

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“…Because they were clusters, the inter-cluster segments were already removed. In addition, they were ␤-LDs, in which the external chains also were largely removed and shortened into stubs of ECL 1-3 [19] that are resistant to attack [15]. Using a concentrated enzyme solution (200 times higher than that used for isolation of clusters), it is, however, possible to further hydrolyse the internal chains of the clusters until the building blocks are obtained.…”

Section: Discussionmentioning

confidence: 99%

“…The average CL of the building blocks in potato and amaranth clusters was only ∼4, whereas the internal chain length (ICL) was ∼2 and ∼3, respectively [11,13]. The exact molecular structure of the different blocks was not characterized, but earlier studies on the detailed structure of ␣-limit dextrins obtained from waxy rice amylopectin [14][15][16] give a good opportunity to understand their type of structures. In the potato clusters the building blocks were interconnected through internal chain segments with ICL 7-8 and in amaranth ∼6.8.…”

Section: Introductionmentioning

confidence: 99%

The fine structure of cassava starch amylopectin. Part 2: Building block structure of clusters

Bertoft

Laohaphatanalert

Piyachomkwan

et al. 2010

International Journal of Biological Macromolecules

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“…14 The actual average ICL between the branches of two adjacent building blocks (inter-block CL, IB-CL) is longer, however, because the enzyme cannot attack the glucosidic linkages next to the branches. 31 Therefore, IB-CL approximately equals 14 IB-DP + 4 and was $6.8. As expected from the suggested structural definition of a cluster, 14 the length between the building blocks inside the clusters was thus <9 residues and much shorter than the inter-cluster chain length (IC-CL, 10.7-13.8, Table 5).…”

Section: Internal Structure Of the Clustersmentioning

confidence: 93%