INTERNATIONAL DENTAL JOURNAL
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2024
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IF 3.2
Yunxiao Du,Guobin Li,Xinglin Li,Xiaohong Jian,Xiaoling Wang,Yongmei Xie,Zaixin Li,Zhi Zhang
Objective The purpose of this work was to develop an anti-CAT-SYI immunoglobulin Y (IgY) antibody that targeted both GtfB (glucosyltransferase B) and GbpB (glucan-binding protein B) and test its anticaries properties in rats. Methods A new CAT-SYI fusion gene was created utilising functional DNA fragments from the GtfB and GbpB genes. The recombinant antigens, comprising the fused CAT-SYI antigen, GtfB, and GbpB, were expressed and purified using a prokaryotic expression and purification system. The purified recombinant antigens were utilised to immunise laying hens against particular IgY production. The biological activities of these particular IgY antibodies were then assessed both in vitro and in vivo, including their capacity to suppress biofilm formation and tooth caries. Results Results indicated that these produced IgY antibodies demonstrated a high antibody titer (>0.1 μg/mL) and could precisely recognise and bind to their respective antigens. Furthermore, it was discovered that these specific IgY antibodies successfully bind to Streptococcus mutans and significantly reduce biofilm development. After 8 weeks of ingesting antigen-specific IgY meals, comprising anti-GtfB IgY and anti-GbpB IgY, the severity of dental caries was dramatically reduced in S mutans– infected Sprague-Dawley rats ( P < .01). Anti-CAT-SYI IgY therapy significantly reduced tooth cavities by 89.0% in vivo ( P < .05) compared to other treatment groups. Conclusions The anti-CAT-SYI IgY, a multitarget antibody that targets both GtfB and GbpB, displayed excellent inhibitory effects against S mutans , making it a promising targeted method with improved anticaries efficacy and significant application opportunities.
研究领域:
口腔生物学
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免疫学
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2024
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IF 10.7
Jingjing Dong,Yanli Wang,Ying Chen,Qin Wang,Bo Zhang,Xiaoxiao Li,Zhengyu Jin,Yuxiang Bai
The recently characterized Limosilactobacillus reuteri N1 GtfB (LrN1 GtfB) from glycoside hydrolase family 70 is a novel 4,6-α-glucanotransferase acting on starch/maltooligosaccharides with high enzyme activity and soluble protein yield (in heterogenous system). In this study, the influence of the treatment by LrN1 GtfB on the fine structure and functional characteristics of three maize starches were furtherly investigated and elucidated. Due to the treatment of LrN1 GtfB, the starch molecules were transformed into reuterans containing linear and branched (α1 → 6) linkages with notably smaller molecular weight and shorter chain length. Moreover, the (α1 → 6) linkage ratios in the GtfB-modified high-amylose maize starch (GHMS)/normal maize starch (GNMS)/waxy maize starch (GWMS) increased by 18.3 %/12.6 %/9.0 % as compared to their corresponding controls. In vitro digestibility experiment revealed that the resistant starch content of GHMS, GNMS and GWMS increased by 16 %, 18 % and 25 % as compared to the starch substrates. Furthermore, the butyric acid yielded from GHMS, GNMS and GWMS in the in vitro fermentation experiments were 1.4, 1.5 and 1.4 times higher than those of commercial galactose oligosaccharides . These results indicated that the highly-branched short-clustered reuteran synthesized by LrN1 GtfB might serve as novel potential prebiotics , and provide insights for the synthesis of promising prebiotic dietary fiber from starch.
研究领域:
食品科学
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微生物学
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营养学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
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IF 5.7
Nana Wang,Jingjing Dong,Xiaoxiao Li,Birte Svensson,Zhengyu Jin,Yuxiang Bai
Limosilactobacillus reuteri 121 4,6-α-glucanotransferase GtfB (Lr 121 GtfB), belonging to glycoside hydrolase family 70 (GH70), synthesizes linear isomalto/malto polysaccharides having (α1→6) linkages attached to the nonreducing ends of (α1→4) linked maltose oligosaccharide segments using starch or maltodextrin as a substrate. Since Lr 121 GtfB has low catalytic activity and efficiency, it leads to substrate regeneration and reduced substrate utilization. In this study, we superimposed the crystal structure of Lr 121 GtfB-ΔNΔV with that of L. reuteri NCC 2613 GtfB-ΔNΔV (Lr 2613 GtfB-ΔNΔV) to identify the acceptor binding subsites +1 to +3 and constructed five single-residue mutants and a random mutagenesis of N1019. Compared with the wild-type, N1019D Lr 121 GtfB-ΔN did not alter the product specificity, increased the catalytic activity and efficiency by 420 and 590%, respectively, and maintained >80% relative activity in the pH 3.5–6.5 interval. The findings will contribute to the industrial application of Lr 121 GtfB and provide new solutions for starch synthesis of higher value derivatives.
研究领域:
微生物学
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生物化学
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酶学
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生物技术
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2022
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IF 5.895
Yawen Jiang,Xiaoxiao Li,Tjaard Pijning,Yuxiang Bai,Lubbert Dijkhuizen
Limosilactobacillus reuteri 121 4,6-α-glucanotransferase (Lr121 4,6-α-GTase), belonging to the glycosyl hydrolase (GH) 70 GtfB subfamily, converts starch and maltodextrins into linear isomalto/malto polysaccharides (IMMPs) with consecutive (α1 → 6) linkages. The recent elucidation of its crystal structure allowed identification and analysis of further structural features that determine its reaction and product specificity. Herein, sequence alignments between GtfB enzymes with different product linkage specificities (4,6-α-GTase and 4,3-α-GTase) identified amino acid residues in GH70 homology motifs, which may be critical for reaction and product specificity. Based on these alignments, four Lr121 GtfB-ΔN mutants (I1020M, S1057P, H1056G, and Q1126I) were constructed. Compared to wild-type Lr121 GtfB-ΔN, mutants S1057P and Q1126I had considerably improved catalytic efficiencies. Mutants H1056G and Q1126I showed a 9% decrease and an 11% increase, respectively, in the ratio of (α1 → 6) over (α1 → 4) linkages in maltodextrin-derived products. A change in linkage type (e.g., (α1 → 6) linkages to (α1 → 3) linkages) was not observed. The possible functional roles of these Lr121 GtfB-ΔN residues located around the acceptor substrate-binding subsites are discussed. The results provide new insights into structural determinants of the reaction and product specificity of Lr121 GtfB 4,6-α-GTase.
研究领域:
酶学
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分子生物学
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微生物学
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DOI
PubMed
高影响因子
Food Bioscience
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2024
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IF 4.8
Jingjing Dong,Yanli Wang,Xiaoxiao Li,Ying Chen,Rui Fan,Nana Wang,Zhengyu Jin,Yuxiang Bai
The starch-converting GH70 α-glucanotransferases, as the influential enzymatic tools for the synthesis of structurally diverse α-glucans, are of great value in the food industry. In this work, a new GtfB-type α-glucanotransferase from Fructilactobacillus sanfranciscensis Gs2 (FsGs2 GtfB) was mined from the NCBI database, which is highly conserved in four conserved regions I-IV for GtfB enzymes but possessed distinct characteristics in some residues at acceptor subsites +1/+2. Biochemical characterizations revealed that the FsGs2 GtfB enzyme demonstrated a novel 4,6-α-glucanotransferase activity, which was able to cleave the (α1 → 4) linkages in maltooligosaccharide/starch substrates and mainly synthesize branching (α1 → 4,6) linkages in the gelatinized system, resulting in the generation of low-molecular-mass short-clustered (α1 → 4,6)-glucans. Nevertheless, FsGs2 GtfB acted as a quasi-hydrolase instead of transglucosylase in the granular system, causing a notable decrease in the molecular mass of granular wheat starch and a tendency towards shortened chain lengths. Hence, the FsGs2 GtfB enzyme represents an additional potent enzymatic tool of reassembling the (α1 → 4) and (α1 → 6) linkages in starch molecules and enriches the diversity of α-glucans that can be synthesized.
研究领域:
食品科学
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生物化学
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酶工程
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
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IF 5.7
Rui Fan,Jingjing Dong,Xiaoxiao Li,Ying Chen,Zhengyu Jin,Yuxiang Bai
Reuteran is a functional homopolysaccharide comprising major (α1 → 4) and interspersed (α1 → 6) linkages whose properties and functions are directly associated with the structure. In order to enrich the structural variety and application prospects of reuteran, a GtfB-type 4,6-α-glucanotransferase from Limosilactobacillus mucosae L24-B (LmGtfB), which can synthesize reuteran with high-content linear (α1 → 6) linkages, was screened. LmGtfB exhibited 4,6-α-glucanotransferase activity against starch or dextrin and can synthesize both linear and branching (α1 → 6) linkages, which offered advantages in terms of source and cost. The as-produced reuteran had the highest content of linear (α1 → 6) linkages (19% in the methylation result) among the reuterans synthesized by other GtfB-type 4,6-α-glucanotransferases. A purification method was established and applied to the extraction of the core structure of the LmGtfB products. 1H NMR and enzymatic hydrolysis revealed that the core structure contains 46.24% (α1 → 6) linkages and alternating (α1 → 4)/(α1 → 6) linkages, which was formed by enzymatic transfer of maltose.
研究领域:
生物化学
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微生物学
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碳水化合物化学
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酶学
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2023
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IF 11.2
Yixi Liu,Yazhen Wu,Hangyan Ji,Xiaoxiao Li,Zhengyu Jin,Birte Svensson,Yuxiang Bai
Isomalto/malto-polysaccharides (IMMPs) derived from malto-oligosaccharides such as maltoheptaose (G7) are elongated non-branched gluco-oligosaccharides produced by 4,6-α-glucanotransferase (GtfB). However, G7 is expensive and cumbersome to produce commercially. In this study, a cost-effective enzymatic process for IMMPs synthesis is developed that utilizes the combined action of cyclodextrinase from Palaeococcus pacificus (PpCD) and GtfB-ΔN from Limosilactobacillus reuteri 121 to convert β-cyclodextrin into IMMPs with a maximum yield (16.19 %, w/w). The purified IMMPs synthesized by simultaneous or sequential treatments, designated as IMMP-Sim and IMMP-Seq, possess relatively high contents of α-(1 → 6) glucosidic linkages. By controlling the release of G7 and smaller malto-oligosaccharides by PpCD, IMMP-Seq was obtained of DP varying from 12.9 to 29.5. Enzymatic fingerprinting revealed different linkage-type distribution of α-(1 → 6) linked segments with α-(1 → 4) segments embedded at the reducing end and middle part. The proportion of α-(1 → 6) segments containing the non-reducing end was 56.76 % for IMMP-Sim but 28.98 % for IMMP-Seq. Addition of G3 or G4 as specific acceptors resulted in IMMPs exhibiting low polydispersity . This procedure can be applied as a novel bioprocess that does not require costy high-purity malto-oligosaccharides and with control of the average DP of IMMPs by adjusting the substrate composition .
研究领域:
生物化学
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食品科学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2026
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IF 6.2
Xiaoxiao Li,Ying Chen,Zhengyu Jin,Yuxiang Bai
The GH70 family 4,3/6-α-glucanotransferase efficiently converted readily digestible (α1→4) glycosidic bonds into (α1→3) or (α1→6) glycosidic bonds, thus serving as an effective enzymatic tool for preparing starch-based dietary fiber. Amino acid residues, including V1409, Q1397, T1366, K1362, H1369, and N1418 of Limosilactobacillus fermentum NCC 2970 GtfB 4,3-α-glucanotransferase (Lf2970 GtfB), were found via sequence conservation analysis and tunnel engineering for further analysis. Mutants from K1362, T1366, H1369, and N1418 at the tunnel entrance showed increased enzyme activity and catalytic efficiency but reduced molecular weight of products. The mutant Q1397P within the tunnel increased the proportion of (α1→6) bonds in the products to 7.9% and (α1→3) bonds to 26.3%, from the wild-type of 1.2% and 21.9%, respectively. These results indicated that amino acid residues located at the tunnel entrance regulated the enzyme activity and product size of Lf2970GtfB, while the Q1397 site within the tunnel regulated the type and proportion of glycosidic bonds.
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PubMed
高影响因子
危险品化学品经营许可证（带存储）