LANGMUIR
·
2019
·
IF 3.683
Shanshan Wu,Zheng-Zhi Yin,Datong Wu,Yongxin Tao,Yong Kong
π-Conjugated porphyrins have aroused particular attention for nanofabrication and biomimics; however, little attention has been paid to porphyrins-based chiral analysis owing to the achiral feature of porphyrins. Here, we demonstrated a chiral self-assembly of achiral porphyrin induced by l- and d-lysine (l- and d-Lys), and the resultant porphyrin self-assembly exhibited alterable morphologies depending on the inducer used (l- or d-Lys). The supramolecular chirality of the self-assembly was characterized by circular dichroism (CD) spectra, confirming successful transfer of molecular chirality from l- and d-Lys to the self-assembly. The enantioselective property of the chiral self-assembly was also investigated by using tryptophan (Trp) isomers as the model, and the results indicated that the developed chiral self-assembly showed significantly higher affinity toward l-Trp than d-Trp. Also in this work, the l-/d-Lys-induced chiral self-assembly of porphyrin and the supramolecular interaction between the self-assembly and l-/d-Trp were also studied by density functional theory (DFT).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2023
·
IF 11.4
Zixin Teng,Xuewei Pan,Yunran Liu,Jiajia You,Hengwei Zhang,Zhenqiang Zhao,Zhina Qiao,Zhiming Rao
L-serine is a high-value amino acid widely used in the food, medicine, and cosmetic industries. However, the low yield of L-serine has limited its industrial production. In this study, a cellular factory for efficient synthesis of L-serine was obtained by engineering the serine hydroxymethyltransferases (SHMT). Firstly, after screening the SHMT from Alcanivorax dieselolei by genome mining, a mutant Ad SHMT E266M with high thermal stability was identified through rational design. Subsequently, an iterative saturating mutant library was constructed by using coevolutionary analysis, and a mutant Ad SHMT E160L/E193Q with enzyme activity 1.35 times higher than Ad SHMT was identified. Additionally, the target protein Ad SHMT E160L/E193Q/E266M was efficiently overexpressed by improving its mRNA stability. Finally, combining the substrate addition strategy and system optimization, the optimized strain BL21/pET28a- Ad SHMT E160L/E193Q/E266M -5′UTR-REP3 S16 produced 106.06 g/L L-serine, which is the highest production to date. This study provides new ideas and insights for the engineering design of SHMT and the industrial production of L-serine.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2023
·
IF 3.1
Yibo Guo,Ke Shen,Xinshuai Zhang,Hua Huang
l -threonate is the metabolite of vitamin C, while d -erythronate is the metabolite of N -acetyl- d -glucosamine, the nutritional supplement for joint health. They are widely distributed in the environment and human biofluids. Nevertheless, the catabolisms of l -threonate and d -erythronate are sparsely reported. Here we explored the functional diversity of an acid sugar kinase family (Pfam families PF07005-PF17042), and discovered a novel 2-oxo-tetronate kinase. The conserved genome neighborhood of the 2-oxo-tetronate kinase encodes members of class-II fructose-bisphosphate aldolase family (F_bP_aldolase, PF01116) and a dehydrogenase family (PF03446-PF14833). Instructed by this analysis, we experimentally verified that these enzymes are capable of degrading l -threonate into dihydroxyacetone phosphate (DHAP) in Arthrobacter sp. ZBG10, Clostridium scindens ATCC 35704, and Pseudonocardia dioxanivorans ATCC 55486. Meanwhile, a convergent catabolic pathway for d -erythronate was characterized in P . dioxanivorans ATCC 55486. Moreover, the phylogenetic distribution analysis indicates that the biological range of the identified l -threonate and d -erythronate catabolic pathways appears to extend mostly to members of the Actinomycetota , Cyanobacteriota , Bacillota , Pseudomonadota , and Bacteroidota phyla.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·
IF 3.3
Zhuorui Zhang,Yunkai Yan,Jinyang Wang,Jianxi Song,Guiquan Jiang
Xylan-based preservative films were prepared using xylan, chitosan, citric acid and Sanguisorba officinalis L. polyphenols (SOPs) as main components. According to the trend of change in the physical properties of the films, the optimal composition was found to be: 1% xylan, 0.9% chitosan, 0.26% citric acid, and 0.15% SOPs. The effects of SOP content on the films were also determined. The results showed that incorporation of SOPs decreased the TS and EAB of the film and improved the water vapor barrier performance of the film. Scanning electron microscopy, contact angle measurements and thermogravimetric analysis showed that incorporation of SOPs enhanced the compactness, hydrophobicity and thermal stability of the films. Moreover, the films exhibited excellent antibacterial activities in the presence of SOPs. Compared to the polyethylene film, the film delayed spoilage bacteria growth during refrigerated storage of pork, effectively prolonging its shelf life to at least 10 days at 4 °C. In summary, xylan-based SOP preservative films meet the requirements for food packaging materials and have good prospects for use in this field.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD SAFETY
·
2023
·
IF 2.4
Shengjie Li,Feng Cheng,Xueqin Cao,Bakri Mahinur,Maitinuer Maiwulanjiang
As the interest in “natural” and “safe” products grows, the use of natural products instead of synthetic preservatives to combat food spoilage and poisoning caused by microorganisms during processing and storage has become a prioritized option. The present research evaluated the antibacterial activity of the Mentha longifolia L. essential oil (MLEO) against several pathogenic bacteria, and the mechanism of action against methicillin-resistant Staphylococcus aureus (MRSA). Gas Chromatography Quadrupole Time-of-Flight Mass Spectrometry (GC-Q-TOF MS) analysis suggested that main components of MLEO were carvone (47.39%) and limonene (12.48%). The oil showed considerable antibacterial activity with MIC values of 0.394–1.576 mg/mL, and could be a promising bactericide. Non-targeted metabolomics analysis based on GC-Q-TOF MS identified 66 different metabolites, and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of these metabolites revealed that MLEO achieves the effects by affecting amino acid metabolism in MRSA.
✓ 已验证
产品关联
DOI
高影响因子
Biotechnology Journal
·
2023
·Vol. 18
·期 9
·2300027
·
IF 4.7
Jian-Miao Xu,Zhou-Sheng Wu,Ke-Ji Zhao,Zhi-Jie Xi,Liu-Yu Wang,Feng Cheng,Ya-Ping Xue,Yu-Guo Zheng
Background Biocatalytic production of L-phosphinothricin (L-PPT) is currently the most promising method. In this work, we use an Escherichia coli strain coexpressing of D-amino acid oxidase and catalase ( E. coli DAAO-CAT) to oxidation biocatalytic D-PPT to PPO, then use the second E. coli strain coexpressing glutamate dehydrogenase and formate dehydrogenase ( E. coli GluDH-FDH) to reduce biocatalytic PPO to L-PPT. Main Methods and Major Results We compared the effects of different concentrations of IPTG or lactose on protein expression and enzyme activity in 5 L fermenter. The best induction conditions for E. coli DAAO-CAT were 0.05 mM IPTG, induction for 18 h at 28°C. The specific enzyme activities of DAAO and CAT were 153.20 U g −1 and 896.23 U g −1 , respectively. The optimal induction conditions for E. coli GluDH-FDH were 0.2 mM IPTG, induction for 19 h at 28°C. The specific enzyme activities of GluDH and FDH were 41.72 U g −1 and 109.70 U g −1 , respectively. The 200 mM D-PPT was biocatalyzed by E. coli DAAO-CAT for 4 h with space-time yield of 9.0 g·L −1 ·h −1 and conversion rate of over 99.0%. Then 220 mM PPO was converted to L-PPT by E. coli GluDH-FDH for 3 h with space-time yield of 14.5 g·L −1 ·h −1 and conversion rate of over 99.0%. To our knowledge, this is the most efficient biocatalytic reaction for L-PPT production. Conclusions and Implications We found that IPTG has advantages compared with lactose in the enzyme activity and biomass of E. coli DAAO-CAT and E. coli GluDH-FDH, and IPTG is more environmentally friendly. Our data implicated that IPTG can replace lactose in terms of economic feasibility and effectiveness for scaled-up industrial fermentations. Graphical and Lay Summary A two-step enzymatic method was developed for the biological preparation of L-PPT from D-PPT. In the first step, we constructed a recombinant E. coli BL21(DE3)/pCDFDuet-DAAO-CAT that utilized D-amino acid oxidase (DAAO) to catalyze the conversion of D-PPT to PPO, and catalase to degrade the hydrogen peroxide (H 2 O 2 ) produced during the reaction. Subsequently, in the second step, we constructed another recombinant E. coli BL21(DE3)/pETDuet-LcGluDH-PseFDH that employed glutamate dehydrogenase (GluDH) for the reductive amination of PPO to L-PPT, with NADH supplied by formate dehydrogenase (FDH).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF PHYTOREMEDIATION
·
2023
·
IF 3.7
Faming Zhang,Jiansong Peng,Yuhong Rong,Shixian Sun,Yi Zheng
The long-term widespread application of atrazine poses significant threats to the eco-environment and human health. To investigate the potential of vetiver (Chrysopogon zizanioides L.) for phytoremediation of the environmental media contaminated by atrazine, an indoor incubation experiment was conducted in submerged soil over 30 days. Results showed that the chlorophyll level of the vetiver was not significantly affected by exposure to atrazine. Vetiver could take up and accumulate atrazine from submerged soil and peaked around the 20th day with a concentration of 1.0 mg kg−1 in leaf. The metabolites Hydroxyatrazine (HA), deethylatrazine (DEA), Deisopropylatrazine (DIA), and didealkylatrazine (DDA) were detected in the leaf on the 30th day, indicating vetiver could degrade atrazine inside the leaf tissue. The atrazine removal rate in the vetiver planted and unplanted jars were 69.72 and 60.29%, respectively, indicating that 9.43% higher atrazine removal was achieved in the presence of vetiver (p < 0.05). The atrazine dissipation in the submerged soil followed first-order kinetics, the degradation constant was 0.066, and the half-life of atrazine dissipation was shortened by 6.86 days in the presence of vetiver. The present study suggests that vetiver can take up atrazine from submerged soil and accumulate in the leaf, which could then degrade in the leaf.Novelty statement: Although the fate of atrazine in agricultural soils has been extensively investigated through various experiments, little is known about the effect of vetiver grass on atrazine dissipation from submerged soil. With the identification of soil-leaf transportation and four metabolites in vetiver leaf and soils, significantly accelerated atrazine dissipation from the submerged soil was achieved in the presence of vetiver. Particularly, the formation of less toxic dealkylated products in the leaf indicated vetiver is a promising grass for atrazine removal from submerged soil.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
·
2023
·
IF 4.1
Yifan Li,Shujun Ni,Yunping Wang,Ruichi Li,Hong Sun,Xuan Ye,Zhen Tian,Yalin Zhang,Jiyuan Liu
BACKGROUND Insecticide resistance continuously poses a threat to agricultural production. Chemosensory protein-mediated resistance is a new mechanism of insecticide resistance discovered in recent years. In-depth research on resistance mediated by chemosensory proteins (CSPs) provides new insight into aid insecticide resistance management. RESULTS Chemosensory protein 1 in Plutella xylostella ( PxCSP1 ) was overexpressed in the two indoxacarb-resistant field populations and PxCSP1 has a high affinity with indoxacarb. PxCSP1 was upregulated when exposed to indoxacarb and the knockdown of this gene elevated sensitivity to indoxacarb, which demonstrate that PxCSP1 is involved in the indoxacarb resistance. Considering that CSPs may confer resistance in insects via binding or sequestering, we explored the binding mechanism of indoxacarb in PxCSP1 -mediated resistance. Using molecular dynamics simulations and site-directed mutation, we found that indoxacarb forms a solid complex with PxCSP1 mainly through van der Waals interactions and electrostatic interactions. Between these, the electrostatic interaction provided by the Lys100 side chain in PxCSP1 , and especially the hydrogen bonding between the NZ atom and the O of the carbamoyl carbonyl group of indoxacarb, are the key factors for the high affinity of PxCSP1 to indoxacarb. CONCLUSIONS The overexpression of PxCPS1 and its high affinity to indoxacarb is partially responsible for indoxacarb resistance in P. xylostella . Modification of indoxacarb's carbamoyl group has the potential to alleviate indoxacarb resistance in P. xylostella . These findings will contribute to solving chemosensory protein-mediated indoxacarb resistance and provide a better understanding of the insecticide resistance mechanism. © 2023 Society of Chemical Industry.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 2
·596
·
IF 4.6
Qiongqiong Wang,Shiqi Liu,Long Xu,Bin Du,Lijun Song
Polysaccharides are the main bioactive components in safflower. In this study, safflower polysaccharides (SPs) were extracted by ultrasonic assisted extraction, and four purified safflower polysaccharide fractions (named SSP1, SSP2, SSP3, and SSP4, respectively) were obtained. The physicochemical properties and in vitro physiological activities of the four fractions were investigated. The molecular weights (MW) of the SSPs were 38.03 kDa, 43.17 kDa, 54.49 kDa, and 76.92 kDa, respectively. Glucuronic acid, galactose acid, glucose, galactose, and arabinose were the main monosaccharides. The Fourier transform infrared spectroscopy (FT-IR) indicated that the polysaccharides hadα- andβ-glycosidic bonds. Nuclear magnetic resonance (NMR) analysis showed that SSP1 had 6 different types of glycosidic bonds, while SSP3 had 8 different types. SSP3 exhibited relatively higher ABTS+scavenging activity, Fe+3-reduction activity, and antiproliferative activity. The results will offer a theoretical framework for the use of SPs in the industry of functional foods and medications.Keywords:safflower;polysaccharides;structures characterization;physiological activities
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2019
·Vol. 11
·期 3
·440
·
IF 3.164
Deyu Kong,Deli Zhang,Hongge Guo,Jian Zhao,Zhaobo Wang,Haiqing Hu,Junting Xu,Cuiliu Fu
In this work, hydroxyl-functionalized boron nitride nanosheet (OH-BNNS) was prepared and was blended with poly(l-lactide) (PLLA) to yield PLLA/OH-BNNS nanocomposites with excellent dispersion of OH-BNNS via the interaction of carbonyl in PLLA and hydroxyl in OH-BNNS. The effects of OH-BNNS on the crystallization and melting behaviors, isothermal crystallization kinetics, macroscopic crystal morphology and crystal structure of PLLA were studied by means of various techniques. The addition of OH-BNNS nanofillers can effectively accelerate the crystallization of PLLA and enhance the nucleation density, leading to a smaller spherulite size, increased crystallinity, a more obvious crystallization peak upon cooling but weakened cold crystallization behavior upon heating. Low OH-BNNS loading can increase the relative content of α-crystal, but the relative content of less perfect α′-crystal is increased at high OH-BNNS loading due to the strong interaction between PLLA and OH-BNNS.Keywords:boron nitride;poly(l-lactide);nanocomposites;crystallization
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Linlin Li,Hualin Wang,Chongyang Jin,Minmin Chen,Suwei Jiang,Junfeng Cheng,Shaotong Jiang
Zn (II) coordination compounds have aroused growing attentions as antibacterial entities. In the present work, we fabricated a new antibacterial complex of l ‑phenylalanine‑oxidized starch-coordinated zinc (II) ( l ‑Phe-OSt → Zn (II)) by successive reactions of oxidization, Maillard and coordination. Maillard reaction occurred between l ‑Phe and OSt to form l ‑Phe-OSt, which was then coordinated with Zn (II) by carboxyl groups for l ‑Phe-OSt → Zn (II). The complex showed good antibacterial activity and the antibacterial activity against E. coli was slightly poorer than B. subtilis . The presence of complex favored the generation of reactive oxygen species (ROS) in bacteria and the ROS level in B. subtilis was higher than that in E. coli . Furthermore, the toxicity of l ‑Phe-OSt → Zn (II) towards HT-29 cells was very low. The characteristics of better antibacterial activity and less cytotoxicity endow l ‑Phe-OSt → Zn (II) a great potential of application as a food additive.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2018
·
IF 4.244
Mingming Zhang,Juan Qiao,Shufeng Zhang,Li Qi
Herein, a unique protocol based on copper nanoclusters (CuNCs) probe for turn-on fluorescence sensing of L -lysine was developed. The fluorescent CuNCs with ovalbumin as the stabilizer was prepared by a simple, one-step and green method. When 370 nm was used as the excitation wavelength, the resultant CuNCs exhibited a pale blue fluorescence with the maximum emission at 440 nm. Interestingly, existence of L -lysine evoked the obvious fluorescence intensity increase of CuNCs. The detection limit of the proposed method for L -lysine was 5.5 μM, with a good linear range from 10.0 μM to 1.0 mM (r 2 = 0.999). Moreover, the possible mechanism for enhanced fluorescence intensity of CuNCs by addition of L -lysine was explored and discussed briefly. Further, the as-prepared fluorescent CuNCs was successfully applied in detection of L -lysine in urine. Our results demonstrated that L -lysine could be monitored by the probe, providing new path for construction of CuNCs as fluorescent probes and showing great potential in quantification of L -lysine in real samples.
✓ 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）