Structure, specificity and function of cyclomaltodextrinase, a multispecific enzyme of the α-amylase family

Park, Kwan-Hwa; Kim, Tae-Jip; Cheong, Tae-Kyou; Kim, Jung-Wan; Oh, Byung‐Ha; Svensson, Birte

doi:10.1016/s0167-4838(00)00041-8

Cited by 188 publications

(149 citation statements)

References 87 publications

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“…With a mutant ThMA containing the deletion of the N-terminal domain, we previously demonstrated that the domain is important for the dimerization, stability, and substrate preference of the enzyme for ␤-CD (19). We suggested that the narrow and deep activesite cleft shaped by the N-terminal domain that partly covers the otherwise wide and shallow cleft would physically restrict the easy access of the linear starch chain, whereas it allows efficient binding of CDs (1,2). Herein, we demonstrated that the N-terminal domain residue Trp 47 provides a catalytically important interaction with CDs, whereas it provides a mere interaction with soluble starch.…”

Section: Discussionmentioning

confidence: 99%

“…Three groups of enzymes known as cyclomaltodextrinases (CDases; EC 3.2.1.54), maltogenic amylases (MAases; EC 3.2.1.133), and neopullulanases (NPases; EC 3.2.1.135) efficiently hydrolyze cyclomaltodextrins (CDs), 1 which are cyclic oligomers of glucose linked by ␣-D-(1,4)-glycosidic bonds (1). Comparatively, these enzymes hydrolyze starch and pullulan inefficiently.…”

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confidence: 99%

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Cyclomaltodextrinase, Neopullulanase, and Maltogenic Amylase Are Nearly Indistinguishable from Each Other

Lee¹,

Kim²,

Cho³

et al. 2002

Journal of Biological Chemistry

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146

124

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Over 20 enzymes denoted as cyclomaltodextrinase, maltogenic amylase, or neopullulanase that share 40 -86% sequence identity with each other are found in public data bases. These enzymes are distinguished from typical ␣-amylases by containing a novel N-terminal domain and exhibiting preferential substrate specificities for cyclomaltodextrins (CDs) over starch. In this research field, a great deal of confusion exists regarding the features distinguishing the three groups of enzymes from one another. Although a different enzyme code has been assigned to each of the three different enzyme names, even a single differentiating enzymatic property has not been documented in the literature. On the other hand, an outstanding question related to this issue concerns the structural basis for the preference of these enzymes for CDs. To clarify the confusion and to address this question, we have determined the structures of two enzymes, one from alkalophilic Bacillus sp. I-5 and named cyclomaltodextrinase and the other from a Thermus species and named maltogenic amylase. The structure of the Bacillus enzyme reveals a dodecameric assembly composed of six copies of the dimer, which is the structural and functional unit of the Thermus enzyme and an enzyme named neopullulanase. The structure of the Thermus enzyme in complex with ␤-CD led to the conclusion that Trp 47 , a well conserved N-terminal domain residue, contributes greatly to the preference for ␤-CD. The common dimer formation through the novel N-terminal domain, which contributes to the preference for CDs by lining the active-site cavity, convincingly indicates that the three groups of enzymes are not different enough to preserve the different names and enzyme codes.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Cyclomaltodextrinase, Neopullulanase, and Maltogenic Amylase Are Nearly Indistinguishable from Each Other

Lee¹,

Kim²,

Cho³

et al. 2002

Journal of Biological Chemistry

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146

124

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“…Meanwhile, maltogenic α-amylase (EC 3.2.1.133) hydrolyze α-1,4-glucosidic linkages of starch and its derivatives to maltose reducing the chain length of the polymer [9]. MA also exhibits high transglycosylation activity via formation of various glycosidic linkages such as α-1,6 producing branched oligosaccharides [10]. In this way, the combination of branching followed by posterior trimming through a starch-active exo-hydrolase, such as β-amylase or maltogenic α-amylase, has been attempted to change the amylopectin fine structure to create resistant structures that slow down the starch digestion properties in native and cooked matrices.…”

Section: Introductionmentioning

confidence: 99%

Changes in physicochemical properties and in vitro starch digestion of native and extruded maize flours subjected to branching enzyme and maltogenic α-amylase treatment

Román

Martínez

Rosell

et al. 2017

International Journal of Biological Macromolecules

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Extrusion is an increasingly used type of processing which combined with enzymatic action could open extended possibilities for obtaining clean label modified flours. In this study, native and extruded maize flours were modified using branching enzyme (B) and a combination of branching enzyme and maltogenic α-amylase (BMA) in order to modulate their hydrolysis properties. The microstructure, pasting properties, in vitro starch hydrolysis and resistant starch content of the flours were investigated. Whereas BMA treatment led to greater number of holes on the granule surface in native samples, B and BMA extruded samples showed rougher surfaces with cavities. A reduction in the retrogradation trend was observed for B and BMA native flours, in opposition to the flat pasting profile of their extruded counterparts. The glucose release increased gradually for native flours as the time of reaction did, whereas for extruded flours a fast increase of glucose release was observed during the first minutes of reaction, and kept till the end, indicating a greater accessibility to their porous structure. After 16 hours of hydrolysis, resistant starch content was lower for treated extruded samples. These results suggested that, in enzymatically treated extruded samples, changes produced at larger hierarchical levels in their starch structure could have masked a slowdown in the starch digestion properties.

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“…Usually, ␣-amylases cannot hydrolyze CDs, but Thermoactinomyces vulgaris R-47 ␣-amylase 2 (TVAII, 585 amino acids, 67,500 Da) can efficiently hydrolyze CDs by what is called cyclodextrinase activity (2).…”

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confidence: 99%

Complex Structures of Thermoactinomyces vulgaris R-47 α-Amylase 2 with Acarbose and Cyclodextrins Demonstrate the Multiple Substrate Recognition Mechanism

Ohtaki

Mizuno

Tonozuka

et al. 2004

Journal of Biological Chemistry

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Thermoactinomyces vulgaris R-47 ␣-amylase 2 (TVAII) has the unique ability to hydrolyze cyclodextrins (CDs), with various sized cavities, as well as starch. To understand the relationship between structure and substrate specificity, x-ray structures of a TVAII-acarbose complex and inactive mutant TVAII (D325N/D421N)/␣-, ␤-and ␥-CDs complexes were determined at resolutions of 2.9, 2.9, 2.8, and 3.1 Å, respectively. In all complexes, the interactions between ligands and enzymes at subsites ؊1, ؊2, and ؊3 were almost the same, but striking differences in the catalytic site structure were found at subsites ؉1 and ؉2, where Trp 356 and Tyr 374 changed the conformation of the side chain depending on the structure and size of the ligands. Trp 356 and Tyr 374 are thought to be responsible for the multiple substraterecognition mechanism of TVAII, providing the unique substrate specificity. In the ␤-CD complex, the ␤-CD maintains a regular conical structure, making it difficult for Glu 354 to protonate the O-4 atom at the hydrolyzing site as a previously proposed hydrolyzing mechanism of ␣-amylase. From the x-ray structures, it is suggested that the protonation of the O-4 atom is possibly carried out via a hydrogen atom of the inter-glucose hydrogen bond at the hydrolyzing site.

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Structure, specificity and function of cyclomaltodextrinase, a multispecific enzyme of the α-amylase family

Cited by 188 publications

References 87 publications

Cyclomaltodextrinase, Neopullulanase, and Maltogenic Amylase Are Nearly Indistinguishable from Each Other

Cyclomaltodextrinase, Neopullulanase, and Maltogenic Amylase Are Nearly Indistinguishable from Each Other

Changes in physicochemical properties and in vitro starch digestion of native and extruded maize flours subjected to branching enzyme and maltogenic α-amylase treatment

Complex Structures of Thermoactinomyces vulgaris R-47 α-Amylase 2 with Acarbose and Cyclodextrins Demonstrate the Multiple Substrate Recognition Mechanism

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