JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Chunhua Zhu,Tao Hong,Mingjing Mou,Yanhong Chen,Zhipeng Li,Mingjing Zheng,Zedong Jiang,Hui Ni,Yanbing Zhu
The immobilized κ-carrageenase MCNF was developed by synergistic integration of κ-carrageenase, calcium phosphate crystals, and magnetic nanoparticles. MCNF outperformed free κ-carrageenase in terms of optimal temperature, thermostability (45–55 °C), stability (pH 6.0 and 12.0), and storage stability. Furthermore, MCNF was extremely reusable and easy to separate from the reaction system. MCNF’s enzymatic breakdown of κ-carrageenan resulted in a tetrasaccharide that competitively inhibited pancreatic lipase (PL). Fluorescence titration experiments showed that κ-carrageenan tetrasaccharide altered the microenvironment of PL by causing static bursting of its intrinsic fluorescence. The circular dichroism experiment demonstrated that adding κ-carrageenan tetrasaccharide reduced α-helix content and increased β-sheet content in PL’s secondary structure. Molecular docking and dynamics simulation research suggested that the κ-carrageenan tetrasaccharide could form a stable complex with PL, entering its hydrophobic cavity and occupying its active site, reducing PL’s catalytic activity. κ-Carrageenan tetrasaccharide could inhibit PL, making it a promising therapeutic agent for obesity prevention and treatment.
研究领域:
食品科学
·
生物化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Simiao Liu,Meixi Liu,Yuzhuo Wang,Xin Liu,Fazheng Ren,Hao Zhang
This study investigated the product characteristics and prebiotic properties of lactose-N-neotetraose (LNnT) after the Maillard reaction with α-lactalbumin (α-LA). LNnT and α-LA were reacted in a simulated system at 60 °C and 79 % relative humidity for 96 h to create Maillard reaction products (MRPs). During the reaction, the absorbances at 294 nm and 420 nm and the fluorescence intensity of α-LA-LNnT increased, whereas the free amino groups and free sugar content decreased. Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) analysis revealed that each α-LA was attached with eight LNnT molecules. After the reaction, the far-ultraviolet circular dichroism (CD) and fluorescence spectra showed that the random coil content of α-LA-LNnT significantly increased ( p < 0.05), with the side chains of α-LA's tertiary structure affected. In terms of prebiotic properties, the bacterial density of Bifidobacterium decreased from 0.63 to 0.36, and the short-chain fatty acids production decreased from 12.60 mM to 5.38 mM using the in vitro fermentation medium. In summary, various MRPs were formed by the reaction between LNnT and α-LA at different heating stages, and the Maillard reaction reduced the prebiotic properties of LNnT. The findings provide insights into the impact of the Maillard reaction on the prebiotic properties of human milk oligosaccharides and direct our attention to the interactions of nutrients in infant formula.
研究领域:
食品科学
·
微生物学
·
营养学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Guocong Luo,Zhaolin Huang,Yingying Zhu,Jiajun Chen,Xiaodong Hou,Dawei Ni,Wei Xu,Wenli Zhang,Yijian Rao,Wanmeng Mu
Lacto-N-neotetraose (LNnT), a representative oligosaccharide found in human milk, has been previously examined for its beneficial traits. However, the LNnT titer is limited by the efficient glycosyltransferase pathway, particularly with respect to the catalysis of rate-limiting steps. As data on the crystal structure of the key enzyme required for synthesizing LNnT are lacking, the synthesis of LNnT remains an uncertainty. Here, for the first time we report the three-dimensional structure of a bacterial β-1,4-galactosyltransferase, Aaβ4GalT, and analyze the critical role played by residues in its catalytic efficacy. Guided by structural insights, we engineered this enzyme to enhance its catalytic efficiency using structure-guided tunnel engineering. The mutant enzyme L5 (K155M/H156D/F157W/K185M/Q216V) so produced, showed a 50-fold enhancement in catalytic activity. Crystal structure analysis revealed that the mechanism underlying the improvement in activity was of the swing door type. The closed conformation formed by dense hydrophobic packing with Q216V-K155M widened and permitted substrate entry. Our results show that altering the tunnel conformation helped appropriately accommodate the substrate for catalysis and provide a structural basis for the modification of other glycosyltransferases.
研究领域:
生物化学
·
结构生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2022
·Vol. 11
·期 3
·393
·
IF 5.561
Mengke Yao,Min Zhang,Tiantian Lai,Zhennai Yang
The exopolysaccharide (EPS) produced byLactiplantibacillus plantarumNMGL2 isolated from traditional fermented dairy cheese was purified chromatographically with DEAE-Sepharose and Sepharose CL-6B columns. The purified EPS was characterized by various physicochemical methods and in vitro fecal microbiota regulation assay. The results showed that the EPS had a relatively low molecular weight of 3.03 × 104Da, and it had a relatively high degradation temperature of 245 °C as determined by differential scanning calorimetry. Observation of the EPS by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy revealed a highly branched and tangled fibrous network microstructure with many hollow microtubules and spherical particles. Structural study by 1H NMR spectroscopy suggested that the EPS contained a tetrasaccharide repeating unit with monosaccharide components of β-galactose (4.6%), α-glucose (20.6%), and α-mannose (74.8%). The EPS was highly resistant to hydrolysis of simulated human saliva, gastric, and intestinal juices. Moreover, the EPS beneficially affected the composition and diversity of the fecal microbiota, e.g., increasing the relative abundance ofFirmicutesand inhibiting that ofProteobacteria. The results of this study indicated significant bioactivity of this novel low-molecular-weight EPS produced byLpb. plantarumNMGL2, which could serve as a bioactive agent for potential applications in the food and health care industry.Keywords:Lactiplantibacillus plantarumNMGL2;exopolysaccharide;characterization;fecal microbiota
研究领域:
微生物学
·
食品科学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
Algal Research-Biomass Biofuels and Bioproducts
·
2022
·
IF 5.276
Tiancheng Tang,Benwei Zhu,Zhong Yao
Ulvan , extracted from the marine green algae belonging to the genus Ulva , is a complex water-soluble sulfated polysaccharide which mainly composed of four monosaccharides consisting of rhamnose , xylose , glucuronic acid and iduronic acid . Its complex monosaccharide composition gives ulvan great potential for application in the fields of food, pharmaceuticals, and chemistry. And it can be degraded by ulvan lyases mainly from Polysaccharide Lyases (PL) family of PL24, PL25 and PL28 through β -elimination mechanism, which cleaves the β -glycosidic bond between sulfated rhamnose and glucuronic acid or iduronic acid, thereby producing an Ulva oligosaccharide with unsaturated bond. In this study, we have identified a putative ulvan lyase from Alteromonas sp. TK-45 (2). We heterologously expressed, purified, and biochemically characterized the ulvan lyase, which has removed signal peptide . The results show that ULA-1 had best activity at 45 °C and pH 8.0. The K m and V max values were 13.25 μg·mL −1 and 1.719 μmol·min −1 ·mL −1 , respectively. The thermostability of ULA-1 was excellent, and its activity hardly decreased after incubation at 45 °C for 1 h. ESI-MS analysis showed that the primary end-product were disaccharides to tetrasaccharides . In conclusion, our research has expanded the database of ulvan lyase, and provided the possibility to make full use of ulvan, a huge marine biomass resource .
研究领域:
海洋生物学
·
酶学
·
生物技术
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2023
·
IF 11.2
Xiaoli Tang,Zhuqun Wang,Maosen Wang,Shuyu Zhou,Jinghua Chen,Shuqin Xu
Demyelination is a serious complication of neurological disorders, which can be reversed by oligodendrocyte precursor cell (OPC) as the available source of myelination . Chondroitin sulfate (CS) plays key roles in neurological disorders, which still attracted less attention on how CS modulates the fate of OPCs . Nanoparticle coupled with glycoprobe is a potential strategy for investigating the carbohydrate-protein interaction. However, there is lack of CS-based glycoprobe with enough chain length that interact with protein effectively. Herein, we designed a responsive delivery system, in which CS was the target molecule, and cellulose nanocrystal (CNC) was the penetrative nanocarrier . A coumarin derivative (B) was conjugated at the reducing end of an unanimal-sourced chondroitin tetrasaccharide (4mer). This glycoprobe (4B) was grafted to the surface of a rod-like nanocarrier, which had a crystalline core and a poly(ethylene glycol) shell. This glycosylated nanoparticle (N4B-P) displayed a uniform size, improved water-solubility, and responsive release of glycoprobe. N4B-P displayed strong green fluorescence and good cell-compatibility, which imaged well the neural cells including astrocytes and OPCs. Interestingly, both of glycoprobe and N4B-P were internalized selectively by OPCs when they were incubated in astrocytes/OPCs mixtures. This rod-like nanoparticle would be a potential probe for studying carbohydrate-protein interaction in OPCs.
研究领域:
神经科学
·
纳米技术
·
生物材料
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOORGANIC CHEMISTRY
·
2025
·
IF 4.7
Shuying Li,Han Gao,Jielin Zhao,Guirong Wang,Guofeng Gu
Hepatocellular carcinoma (HCC) is one of the most prevalent malignant tumors worldwide. Studies have documented the antitumor activities of various polysaccharides derived from Antrodia cinnamomea (AC); however, to date, the antitumor activity of the oligosaccharide fragment related to galactomannan polysaccharide in AC remains unreported. In this study, we disclosed that the backbone tetrasaccharide derivative of AC galactomannan, designated as ACP-3, demonstrates specific binding to mannose receptors (MR) on the surface of Hep G2 cells, facilitating its cellular internalization. This interaction thereby elicited potent antiproliferative effects through dual mechanisms: ROS/JNK signaling-induced apoptosis and ROS-mediated autophagy-induced cell death. In vivo studies further validated the tumor-targeting capability of ACP-3, as monotherapy significantly suppresses the growth of H22 solid tumors. Notably, the co-administration of ACP-3 with cyclophosphamide (CTX) could synergistically enhance antitumor activity and concurrently alleviate CTX-induced adverse effects such as weight loss, hepatorenal toxicity, and immune dysfunction. These findings collectively establish ACP-3 as a promising therapeutic candidate for the treatment of HCC.
研究领域:
肿瘤学
·
分子生物学
·
药理学
·
天然产物化学
·
免疫学
·
细胞信号传导
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2024
·
IF 3.4
Caixia Pei,Xinlv Peng,Yiran Wu,Runmiao Jiao,Tiehai Li,Siming Jiao,Lei Zhou,Jianjun Li,Yuguang Du,Eika W. Qian
Eukaryotic sialyltransferases play key roles in many physiological and pathological events. The expression of active human recombinant sialyltransferases in bacteria is still challenging. In the current study, the genes encoding human N -acetylgalactosaminide α2,6-sialyltransferase V (hST6GalNAc V) and N -acetylgalactosaminide α2,6-sialyltransferase VI (hST6GalNAc VI) lacking the N -terminal transmembrane domains were cloned into the expression vectors, pET-32a and pET-22b, respectively. Soluble and active forms of recombinant hST6GalNAc V and hST6GalNAc VI when coexpressed with the chaperone plasmid pGro7 were successfully achieved in Escherichia coli . Further, lactose (Lac), Lacto- N -triose II (LNT II), lacto- N -tetraose (LNT), and sialyllacto- N -tetraose a (LSTa) were used as acceptor substrates to investigate their activities and substrate specificities. Unexpectedly, both can transfer sialic acid onto all those substrates. Compared with hST6GalNAc V expressed in the mammalian cells, the recombinant two α2,6-sialyltransferases in bacteria displayed flexible substrate specificities and lower enzymatic efficiency. In addition, an important human milk oligosaccharide disialyllacto- N -tetraose (DSLNT) can be synthesized by both human α2,6-sialyltransferases expressed in E. coli using LSTa as an acceptor substrate. To the best of our knowledge, these two active human α2,6-sialyltransferases enzymes were expressed in bacteria for the first time. They showed a high potential to be applied in biotechnology and investigating the molecular mechanisms of biological and pathological interactions related to sialylated glycoconjugates.
研究领域:
分子生物学
·
生物化学
·
生物技术
·
酶学
·
糖生物学
✓ 已验证
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Lei Zhang,Lingli Zhong,Juying Wang,Yuqiang Zhao,Yiwei Zhang,Yitong Zheng,Weiliang Dong,Xianfeng Ye,Yan Huang,Zhoukun Li,Zhongli Cui
The process of raw starch conversion has attracted extensive attention in recent years due to its high energy conversion efficiency and saving of operational costs. In this study, extensive hydrolysis of raw starch by α-amylase AmyM from Corallococcus sp. EGB was investigated with robust substrate and products tolerance. AmyM showed broad substrate specificity toward raw starches with different types, and kept active and stable over a wide range of temperatures (30–70 °C) and pH values (5.0–9.0) and recycling. The V max values of AmyM towards wheat and corn raw starch were 1111 and 741 μmol/min/mg without depending on Ca 2+ , respectively. SEM analysis showed that AmyM hydrolysis results in the formation of porous and creviced surfaces around the starch granules peripheries. The cost-effective conversion of raw starch for the production of malto-oligosaccharides (MOSs) was identified. AmyM achieved high hydrolysis degree of 90% for 30% wheat and corn raw starch after 20 h at 45 °C with 5 U per mg of raw starch, resulting in formation of 70% MOSs and 30% dextrin. During this process, maltose (G2), maltotriose (G3) and maltotetraose (G4) were produced synchronously with G9 and G11, indicating the potential application in enzymatic conversion of raw starch under low temperature.
研究领域:
生物化学
·
酶学
·
食品科学
·
生物技术
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Xi-yang Tang,Zhi-heng Shu,Peng-cheng Zhao,Wen Wei,Cai-lian Fan,Zhi-hong Yao,Xin-sheng Yao,Yi Dai
Zhu-Ling decoction (ZLD), a classical traditional Chinese medicine (TCM) formula, is used for the treatment of chronic kidney diseases. However, the structure and activity of absorbed oligosaccharides (OSs) in ZLD are not clear. In this study, a novel strategy with in vivo characterization, extraction, isolation, activity evaluation was established and applied to identify absorbed anti-inflammatory OSs in ZLD. The results revealed that 30 OSs (22 reducing and 8 non-reducing OSs) and 11 OSs (7 reducing and 4 non-reducing OS) were characterized from ZLD in vitro and in vivo by using UPLC/Q-TOF-MS with PMP derivatization, respectively. Among them, a series of −1 → 3- β -D-Glcp-OSs were isolated and identified by HPLC-HILIC-UVD-ELSD, SPHPLC-HILIC-RID, monosaccharide composition, MS and 1D/2D-NMR spectroscopy, including laminaritriose, laminaritetraose, laminaripentaose, laminarihexaose, laminariheptaose, laminarioctaose and laminarinonaose. Moreover, the 4 non-reducing absorbed OSs were identified by comparison with reference standards, including sucrose, trehalose, raffinose and stachyose. Among them, laminaritriose, laminaritetraose and laminaripentaose significantly inhibited TNF-α and IL-6 levels in LPS-induced HK-2 cell and exerted significant anti-inflammatory effects via the NF-κB and Akt/mTOR signaling pathways. Together, our work provides a novel strategy for discovery of absorbed anti-inflammatory OSs and broadens new horizons for the discovery of in vivo pharmacodynamic substances in TCM formulas.
研究领域:
药理学
·
中药学
·
生物化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）