The Cyclization Mechanism of Cyclodextrin Glycosyltransferase (CGTase) as Revealed by a γ-Cyclodextrin-CGTase Complex at Å. Cyclodextrin glycosyltransferase is an important enzyme of cyclodextrin synthesis . This article mainly discusses the recent progress of the application of. INDUSTRIAL MICROBIOLOGY. Cyclodextrin glycosyltransferase from Bacillus licheniformis: optimization of production and its properties. Cyclodextrina.
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The CGTases are known to be produced by various genera of the bacterial kingdom such as BacillusKlebsiellaPseudomonasBrevibacteriumMicrococus and Clostridium 9. These latter CDs are degraded by coupling glycoeyltransferase in which the products can bind stably inside the crystal 7 Purification and properties of a novel raw starch degrading cyclodextrin glucanotransferase from Bacillus firmus.
Models of cyclization reaction of CGTase on amylose. Km and Vmax values were 1.
Proposed model of the events taking place in the CGTase-catalyzed reactions. Electrophoresis6, The industrial production of CGTase was made attractive only when alkaliphilic Bacillus species were introduced as producing organism The cleaved-off part of the donor substrate has to dissociate from the active site before the acceptor substrate can bind at these acceptor subsites Figure 2A [ 24 ].
Through these applications, the cyclodextrin glycosyltransferase will develop a great contribution to the new type of CD synthesis research area. This is supported by mutants in Phe, which show a greater loss in affinity as judged by the K m value for cyclodextrins than for maltose Reprinted from Chen et al.
The Application of Cyclodextrin Glycosyltransferase in Biological Science | OMICS International
As a result, the torsion angles of the scissile bond have acquired a characteristic twist Circles represent glucose residues; acceptor residues are represented in black.
This hydrogen bond to the substrate agrees better with the role of His as found from mutagenesis studies 3 The first step in cyclization is substrate binding Fig. On this basis, a role of the individual residues during the cyclization reaction cycle is proposed.
Determination of the optimum temperature Two fractions of the culture filtrate were taken for the determination of the optimal hydrolysis temperature. In addition, the electron density and hydrogen bond network suggest that the imizadole ring of His is flipped.
To make this binding contact, the side chain of Arg has assumed a new conformation compared with unliganded wild type CGTase The cyclization activity was determined according to Makela Purification and characterization of an extremely thermostable cyclomaltodextrin glucanotransferase from a glycosyltrqnsferase isolated hyperthermophilic archeon, a Thermococcus sp.
Thereafter it was frozen under a cold nitrogen stream K for data collection using the soaking solution as cryo-protectant.
The Schardinger dextrins, In: Cyclization is the process through which a linear polysaccharidic chain is cleaved and the two ends of the cleaved fragment are joined to produce a cyclodexrrin dextrin cyclodextrin or CD: Cyclodextrin glycosyltransferase from Bacillus licheniformis: The cyclodextrin glucose O6 atom is at a 3.
The Km and Vmax values were estimated using the Eadie-Hofstee plot. Schematic representation of the cyclization reaction catalyzed by CGTase.
This peculiar enzyme is capable of catalyzing more than one reaction with the most important being the synthesis of non-reducing cyclic dextrins known as cyclodextrins starting from starchamyloseand other polysaccharides. Alkalophilic microorganisms, a new microbial worldSpringer, Berlin, From Wikipedia, the free encyclopedia.
The ability of these unusual molecules to form inclusion complexes, which can change the physical and chemical properties of guest molecules, offers a variety of potential uses for food, cosmetic and pharmaceutical industries 3, As expected, both mutants also showed lower affinities for cyclodextrins in the coupling reaction, and a reduced glycosylfransferase product inhibition of the disproportionation reaction by cyclodextrins.
The Application of Cyclodextrin Glycosyltransferase in Biological Science
Determination of the kinetic parameters. Cyclodextrin glycosyltransferase is an important enzyme of cyclodextrin synthesis. Furthermore, crystalline complexes that are the results of this process are stable, a characteristic that can provide many benefits All these activities share the same catalytic mechanism which is common to all glycosyl-hydrolases.
However, cyclization is largely independent of cyclodextrin size, since many amino acids that are typical for CGTase are conserved irrespective of product specificity see below.
Furthermore, they are insoluble and can be separated and recycled many times, increasing their productivity [ 28 ]. An especially interesting and unique family 13 enzyme is cyclodextrin glycosyltransferase CGTase.
Cyclodextrin glycosyltransferase – Wikipedia
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BT and Bacillus macerans. Both glycosyltranscerase were determined under experimentally identical conditions.