Recombinant Cyclodextrin Glycosyltransferase Research Articles

Biosynthesis of methyl glucoside and its antibacterial activity against Staphylococcus aureus and Escherichia coli

In this study, the methyl glucosides (MGn) was synthesized using β-cyclodextrin (β-CD) and methanol through the coupling reaction of recombinant cyclodextrin glycosyltransferase (CGTase) from Bacillus circulans A11. The optimal condition for the synthesis of MGn consisted of an incubation of 1.5% (w/v) β-CD and 500 U/mL of CGTase in a water/methanol solution containing 30% (v/v) methanol at pH 6.0, 50 °C for 120 h. Upon analysis by TLC, at least three MG products were observed. The molecular weight of the main transferred product was 217.08 Da; this value was in accordance with methyl monoglucoside (MG1). MG1 was produced and prepared on a large scale and subsequently purified by preparative TLC. The combined 1H- and 13C-NMR analysis confirmed that the structure of MG1 was methyl-α-d-glucopyranoside. In addition, MG1 showed emulsification activity and stability in its formation in water and n-hexadecane. The antibacterial activity of MG1 was also determined by agar disc diffusion method. The results found that the MG1 (1, 5 and 10 mg/disc) showed antibacterial activity against E. coli ATCC 25922 only, with inhibition zones of 28, 38 and 40 mm, respectively. The MIC values (mg/mL) of MG1 against S. aureus ATCC 25923 and E. coli ATCC 25922 were found to be 20.00 and 0.63, while MBC values (mg/mL) were 40.00 and 0.63, respectively.

Cyclodextrin Glycosyltransferase-Catalyzed Synthesis of Pinoresinol-α-D-glucoside Having Antioxidant and Anti-Inflammatory Activities

Enzymatic synthesis of pinoresinol-α-glucosides (PGs) was performed through the transglycosylation reaction catalyzed by the recombinant cyclodextrin glycosyltransferase (CGTase) from Bacillus circulans A11 using β-cyclodextrin as the glycosyl donor and pinoresinol as the acceptor molecule. Incubation of 0.5% (wt/vol) β-cyclodextrin with 1.5% (wt/vol) pinoresinol (P) and 80.0 U/mL of CGTase in 20 mM of Tris–HCl buffer (pH 9.0) at 50oC for 60 h was optimal for PGs synthesis. Under these conditions, two PG transfer products with molecular weights of 544 and 682 Da corresponding to pinoresinol monoglucoside (PG1-I and PG1-II) and pinoresinol diglucoside (PG2), respectively, were detected by TLC and MS. The structures of PG1 and PG2 were confirmed as pinoresinol-α-D-glucopyranoside and pinoresinol-α-D-diglucopyranoside, respectively, by 1H-NMR analysis. The free-radical scavenging and anti-inflammatory activities of PG1 and PG2 were reduced as compared with the original P using α,α-diphenyl-β-picrylhydrazyl radical scavenging reactions and the β-glucuronidase inhibition assay. The loss of antioxidant and anti-inflammatory activities might result from the addition of glucose in the position 4-OH of P that may have disturbed its electron rotation. In vivo, PGs are converted to Ps before they are absorbed and so loss of activity may be minimal. Interestingly, the α-glycosylated compounds which showed the change of physicochemical properties such as increase of solubility and sweetness could promote a positive effect on the bioavailability of original P.

Cyclodextrin glucosyltransferase immobilization on polydopamine-coated Fe3O4 nanoparticles in the presence of polyethyleneimine for efficient β-cyclodextrin production

An enzymatic approach to β-cyclodextrin synthesis attracts the attention of food engineers and chemists because of the broad applications of β-cyclodextrin in the food industry and the demand for a green process for β-cyclodextrin production. Achieving a high recovery of cyclodextrin glycosyltransferase through immobilization and a high proportion of β-cyclodextrin in a product mixture of cyclodextrins would improve the purification process of β-cyclodextrin. In this study, a recombinant cyclodextrin glycosyltransferase (CGTase) was immobilized on polydopamine-Fe3O4 (PDA-Fe3O4) nanoparticles in the presence of polyethyleneimine (PEI). After optimization of the preparation of the PDA-Fe3O4 nanoparticles and the CGTase immobilization step, 77.9% of the CGTase was recovered. The immobilized CGTase exhibited good thermal and operational stabilities, and gave a ratio of 88.9% β-cyclodextrin when the reaction temperature and kinetic parameters were optimized. Immobilized CGTase was recycled nine times and retained 19.1% β-activity and 0% γ-activity. This study has established a reliable approach to the high recovery of CGTase during efficient β-cyclodextrin production.

Cover Image, Volume 94, Issue 5

The cover image is based on the Research Article Cross‐linked enzyme aggregates of recombinant cyclodextrin glycosyltransferase for high‐purity β‐cyclodextrin production by Jianguo Zhang et al., DOI: 10.1002/jctb.5912. image

Cross‐linked enzyme aggregates of recombinant cyclodextrin glycosyltransferase for high‐purity β‐cyclodextrin production

AbstractBACKGROUNDHigh‐purity α‐, β‐, or γ‐cyclodextrin (CD) production using cyclodextrin glycosyltransferase (CGTase) as biocatalyst to cyclize starch is advantageous owing to its low cost of purification and product specificity. Several approaches have been investigated to enhance product specificity of CGTase, such as new CGTase isolation, CGTase gene (cgt) mutation, and chemical addition.RESULTSRecombinant CGTase was cross‐linked by glutaraldehyde to obtain cross‐linked enzyme aggregates of recombinant CGTase (CLEA‐CGTase) at 85 °C because free CGTase showed high product specificity at 85 °C. The CLEA‐CGTase was prepared under the conditions 75 U mL−1 CGTase with 0.1% (v/v) glutaraldehyde for 10 min at 85 °C after optimization first, and produced a high proportion of β‐CD from soluble starch at 50 °C in the conversion system. The conversion process was carried out with 10 to 200 U mL−1 CLEA‐CGTase, resulting in 100% β‐CD from soluble starch after 420 min conversion of the potato starch solution at 50 °C. And the proportion of β‐CD was still higher than 90% when 8000 U mL−1 CLEA‐CGTase was added.CONCLUSIONSCLEA technology maintained CGTase conformation of 85 °C, and produced a high proportion of β‐CD at 50 °C. This research showed the CLEA technology kept the conformation of enzyme for specific product production. © 2018 Society of Chemical Industry

High-efficiency production of γ-cyclodextrin using β-cyclodextrin as the donor raw material by cyclodextrin opening reactions using recombinant cyclodextrin glycosyltransferase

In comparison with natural α- and β-cyclodextrin (CD), γ-CD has attracted much attention due to their large hydrophobic cavities, high water solubility, and bioavailability. However, the production of γ-CD is still rather expensive and time-consuming. To overcome the high cost and long induction time, pUC119 was selected as the gene expression vector, and the recombinant enzyme production time was reduced to 8h from 72h. Furthermore, for the first time, we have successfully produced γ-CD using β-CD by cyclodextrin opening reactions through the recombinant CGTase in the presence of maltose. The kinetic mechanism of the coupling reaction was investigated. Moreover, the production of γ-CD could be affected by several key parameters, such as solvent type, reaction time, pH, and temperature. A maximum γ-CD yield of 32.9% was achieved by recombinant CGTase in the presence of 5-cyclohexadecen-1-one. This could be a promising method for the industrial production of γ-CD.

Synthesis, structural characterization, and biological properties of pentyl- and isopentyl-α-D-glucosides

The study was devoted to the synthesis of pentyl glucosides (PenGn) and isopentyl glucosides (Iso-PenGn) by transglycosylation using recombinant cyclodextrin glycosyltransferase from Bacillus circulans A11, β-cyclodextrin as a glucosyl donor and 1-pentanol and isopentanol as acceptors. TLC and MS analysis indicated at least 3 products which were in accordance with PenGn and IsoPenGn having glucose, maltose and maltotriose attached to the alkyl groups of both alcohols. Two products of each glucoside were purified by preparative TLC and their structures were identified by NMR technique to be pentyl-α-D-glucopyranoside (PenG1), pentyl-α-D-maltopyranoside (PenG2), isopentyl-α-D-glucopyranoside (IsoPenG1) and isopentyl- α-D-maltopyranoside (IsoPenG2). The effect of water-in-hexadecane emulsion on emulsion-forming properties showed that PenG2 had the highest emulsifying activity. Adding PenG2 to the insoluble Corynebacterium glutamicum amylomaltase from Escherichia coli transformants (A406R), helped to perform it to more soluble conformation. Moreover, it was found that PenG1,2 exhibited a higher antibacterial activity against E. coli ATCC 25922 than that of IsoPenG1,2. Hence, the biological properties of the synthesized products may be useful for their applications as emulsifying, solubilizing and antibacterial agents.

Enzymatic synthesis of propyl-α-glycosides and their application as emulsifying and antibacterial agents

Alkyl glycosides have been effectively used in many industries because of their biodegradable, emulsification and antibacterial properties. In this study, the alkyl glycoside of propyl glycosides (PGn) was synthesized using β-cyclodextrin (β-CD) and 1-propanol through the transglycosylation reaction of recombinant cyclodextrin glycosyltransferase (CGTase) from the Bacillus circulans A11. The optimal condition for the synthesis of propyl glycosides consisted of an incubation of 1.5% (w/v) β-CD and 500 U/mL of CGTase in a water/propanol content containing 10% (v/v) 1-propanol at pH 6.0, 50°C for 96 h. Upon analysis of the product at the optimal condition by TLC, at least three products which move faster than glucose were observed. These transferred products were formed with molecular weights of 222.1, 384.1 and 546.4 daltons as determined by mass spectrometry analysis; these values were in accordance with propyl glucoside (PG1), propyl maltoside (PG2) and propyl maltotrioside (PG3), respectively. PG1 and PG2 were produced and prepared on a large scale and subsequently purified by preparative TLC. The combined 1H- and 13C-NMR analysis confirmed that the structures of PG1 and PG2 were propyl-α-D-glucopyranoside and propyl-α-D-maltopyranoside, respectively. Both PG1 and PG2 showed emulsification activity and stability in their formation in water and n-hexadecane. Furthermore, the antibacterial activity of both products was determined and it was found that PG2 had a higher antibacterial activity against Staphylococcus aureus and Escherichia coli than that of PG1.

Enzymatic Characterization of Recombinant Cyclodextrin Glycosyltransferase from Bacillus sp. a2-5a using Sagoo Starch as Substrate

Cyclodextrin (CD) is a cyclic oligosaccharide molecule and depending on the number of glucose molecules, three types of CDs are commonly used, α-CD, β-CD, and γ-CD. CDs can be produced enzymatically using starch as substrate catalyzed by CD glycosyltransferase (CGTase). In current research, recombinant CGTase production from the synthetic gene was optimized for its production using three growth media and two induction temperatures. The highest yield was obtained in Luria Bertani medium at 25 °C. The rCGTase protein was affinity purified as a 76.39 kDa protein which showed α-cyclization and starch hydrolysis activities using zymography method. The optimum temperature, pH and incubation time was 55 °C, 6, and 24 h, respectively. The enzyme was stable at a wide pHs in the range of 5-10, retained its half activity at 56 °C for 30 min and had cyclization ratio for α-CD : β-CD : γ-CD was 4 : 81 : 15. An amount of 542 mg β-cyclodextrin was produced from 100 mL reaction of 1% (b/v) sagoo starch using 38.4 μg rCGTase in optimum condition. This work reports for the first time the character of rCGTase from Bacillus sp. A2-5a using sagoo starch as a substrate.

Expression and characterization of a fusion protein‐containing cyclodextrin glycosyltransferase from Paenibacillus sp. A11

A recombinant cyclodextrin glycosyltransferase (CGTase) gene fused with thioredoxin (Trx), hexa-histidine (His(6)) and S-protein (S) at the N terminus and a proline-rich peptide (PRP) at the C terminus, was constructed using the wild-type gene from Paenibacillus sp. A11, the pET-32a vector and Escherichia coli BL21(DE3) as the host cell. The expression levels and enzyme characteristics of the Trx-His(6)-CGTase-PRP fusion protein, the recombinant CGTase without fusion peptides, and the wild-type CGTase were compared. The maximum specific activity for the Trx-His(6)-CGTase-PRP fusion enzyme was 2.7 fold higher than that of the non-fusion form at the optimal IPTG concentration. The Trx-His(6)-CGTase-PRP fusion protein was purified to homogeneity by starch adsorption and Ni-NTA affinity chromatography, with a specific activity of 2,268 units/mg protein at a 61% yield. The ease of purification and the higher enzyme yield were obtained with the fusion form when compared to the non-fusion and wild-type enzymes. The fusion enzyme was superior than its wild-type counterpart in terms of stability against high temperature and organic solvents. Moreover, the fusion enzyme could catalyze the synthesis of cyclodextrins in 20% (v/v) dimethylformamide with a higher product yield of CD(7) and CD(8) compared to that of the wild-type enzyme in the same buffer-solvent system.

Extracellular expression, purification, and characterization of the recombinant cyclodextrin glycosyltransferase from Peanibacillus macerans

Extracellular expression, purification, and characterization of the recombinant cyclodextrin glycosyltransferase from Peanibacillus macerans

A recombinant cyclodextrin glycosyltransferase cloned from Paenibacillus sp. strain RB01 showed improved catalytic activity in coupling reaction between cyclodextrins and disaccharides

Recombinant cyclodextrin glycosyltransferase (CGTase) was obtained by cloning the PCR gene fragment from thermotolerant Paenibacillus sp. strain RB01 screened from hot spring area in Thailand and cloned into the Escherichia coli expression vector. The nucleotide sequence was analyzed and aligned. Nucleotide sequence of the recombinant CGTase contained an open reading frame of 2139 bp encoding 713 amino acid residues. The recombinant required one-third of culture time and neutral pH to produce CGTase compared to wild type. CGTases from both wild type and transformant were purified in parallel by starch adsorption and DEAE cellulose column. Their biochemical properties such as molecular weight, optimum pH and temperature were quite similar. However, the recombinant enzyme showed improved catalytic activity in the coupling reaction between cyclodextrins (CDs) and some disaccharides. Among several sugars tested with excess βCD, cellobiose was the best substrate followed by leucrose. Very low activity was observed with trehalose, lactose and mellibiose. Sucrose and raffinose showed no activity. The K m and other kinetic parameters of recombinant enzyme were determined for cellobiose and several cyclodextrin derivatives. Recombinant CGTase showed lower K m for βCD and its derivatives, with improved activity compared to wild type enzyme.