ACS Omega
·
2020
·
IF 2.87
Xinming Feng,Jing Guo,Rubing Zhang,Wei Liu,Yujin Cao,Mo Xian,Huizhou Liu
An aminotransferase ω-TAEn was identified from Enhydrobacter aerosaccus. The ω-TAEn was successfully expressed in Escherichia coli and the obtained enzyme showed activity toward β-phenylalanine (β-phe) at optimal conditions. For optically pure (R)-β-phe, 50% yield was observed by kinetic resolution of racemic amino with pyruvate as the amino acceptor. To obtain (S)-β-phe, the lipase/ω-TAEn catalytic system was adopted. The ω-TAEn showed strict stereoselectivity to the amino donor. The formation of (S)-β-phe was observed using 3-aminobutyric acid as the amino donor, and (S)-β-phe was obtained by asymmetric synthesis with a yield of 82%.
研究领域:
生物化学
·
生物催化
·
酶学
·
化学生物学
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DOI
PubMed
高影响因子
PROTEIN EXPRESSION AND PURIFICATION
·
2024
·
IF 1.4
Junzhang Chang,Yuxin Zhang,Zhiwei Li,Yunfeng Ma,Xueqin Hu,Jingwen Yang,Hongbin Zhang
Chiral amino acids and their deamination products, α-keto acids, have important applications in food, medicine, and fine chemicals. In this study, two l -amino acid deaminase genes from Proteus mirabilis , PM473 of type Ⅰ and PM471 of type Ⅱ were cloned and expressed in Escherichia coli respectively, expected to achieve the chiral separation of amino acids . Extensive substrate preference testing showed that both deaminases had catalytic effects on the d -amino acid component of the D, l -amino acids, and PM473 has a wider catalytic range for amino acids. When D, L-Cys was used as the substrate, all L-Cys components and 75.1 % of D-Cys were converted to mercapto pyruvate , and the remaining D-Cys was a single chiral enantiomer . Molecular docking analysis showed that the interaction between the substrate and the key residues affected the stereoselectivity of enzymes . The compatibility of hydrophobicity between the binding pocket and substrate may be the basic factor that affects the substrate selectivity. This work provides an alternative method for the production of α-keto acids and the resolution of chiral amino acids.
研究领域:
生物化学
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生物催化
·
酶学
·
药物化学
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DOI
PubMed
高影响因子
Molecular Medicine Reports
·
2018
·Vol. 19
·期 2
·841-850
·
IF 1.922
Guangwei Liu,Jiangkai Liu,Linping Pian,Songlin Gui,Baoping Lu
α‑lipoic acid (ALA) is a naturally occurring antioxidant with protective effects against various hepatic injuries. The aim of the present study was to investigate the mechanisms by which ALA protects the liver from carbon tetrachloride (CCl4)‑induced liver cirrhosis. The widely used liver cirrhosis rat model was established via an intraperitoneal injection of 2 mg/kg 50% CCl4, three times/week for 8 weeks. Simultaneously, 50 or 100 mg/kg ALA was orally administrated to the rats every day for 8 weeks. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was detected in the serum. The pathological liver injuries were analyzed using hematoxylin and eosin and Masson's trichrome staining. The principal factors involved in the transforming growth factor‑β (TGF‑β)/mothers against decapentaplegic homolog 9 (Smad3) and protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathways and in autophagy were examined using reverse transcription‑quantitative polymerase chain reaction or western blot analysis. The results demonstrated that the administration of ALA alleviated CCl4‑induced liver injury, as demonstrated by decreased ALT and AST activity, improved pathological injuries and reduced collagen deposition. The CCl4‑induced increase in TGF‑β and phosphorylated‑Smad3 expression levels was additionally inhibited by treatment with ALA. Furthermore, the administration of ALA reversed the CCl4‑induced upregulation of light chain 3II and Beclin‑1, and downregulation of p62. The CCl4‑induced suppression of the AKT/mTOR pathway was additionally restored following treatment with ALA. In combination, the results of the present study demonstrated that ALA was able to protect CCl4‑induced liver cirrhosis, an effect that may be associated with inactivation of the TGF‑β/Smad3 pathway and suppression of autophagy.
研究领域:
肝病学
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药理学
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分子生物学
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DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 38
·24596-24606
·
IF 4.036
Yong-Hong Cai,Jia-Li Zhao,Xin-Yu Guo,Xiao-Juan Zhang,Ran-Ran Zhang,Shao-Rong Ma,Ya-Min Cheng,Zhong-Yan Cao,Ying Xu
Polyaspartic acid (PASP), a well-known green scale inhibitor for industrial water treatment, might be decomposed with prolonged duration, and its anti-scaling performance against CaCO3 and CaSO4 is diminished at a low concentration (<10 mg L−1) and a high temperature. With semi-ethylenediaminetetraacetic acid (EDTA) tetrasodium salt as the mimicking model, novel phosphorus-free PASP-capped 2-aminoethylamino acid (PASP–ED2A) containing side chains bearing multi-functional groups is rationally designed and successfully prepared via the ring-opening reaction of cheap poly(succinimide) under mild reaction conditions with the assistance of readily available 2-aminoethyl amino acid. The static scale inhibition method is used to evaluate the scale inhibition performance of the as-synthesized PASP derivative. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy are utilized to monitor the crystallization process of calcium carbonate and calcium sulfate scales, and density functional theory calculations are conducted to shed light on the relationship between the molecular structure and scale inhibition mechanism of PASP–ED2A. Results show that the as-prepared PASP–ED2A shows better scale inhibition performance for CaCO3 and CaSO4 than PASP with a low concentration, a high temperature, and an extended duration. Particularly, PASP–ED2A with a concentration of 10 mg L−1 exhibits the best scale inhibition performance for CaCO3; its scale inhibition capacity is about two times as much as that of PASP. The reason lies in that the coordination atoms in the molecular structure of PASP–ED2A can chelate with Ca2+ to inhibit the combination of Ca2+ with anions and prevent the generation of CaCO3 and CaSO4 scales. The PASP–ED2A derivative can more efficiently retard the formation and growth of CaCO3 and CaSO4 crystal nuclei and exerts better inhibition performance against CaCO3 and CaSO4 scales than PASP.
研究领域:
材料科学
·
环境科学
·
化学工程
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DOI
高影响因子
JOURNAL OF ANIMAL SCIENCE
·
2020
·Vol. 98
·期 10
·
IF 2.092
Sun Mingfa,Zhao Jingpeng,Wang Xiaojuan,Jiao Hongchao,Lin Hai
The supplementation of dietary limiting amino acids (AA) with crystalline AA makes the use of low-protein diets an option in poultry production. The differing absorption rates of crystalline and protein-bound AA may lead to temporally imbalanced AA in the postabsorptive period. In this study, two experiments were conducted to evaluate the effect of encapsulated L-lysine-HCl (L-Lys-HCl) and DL-methionine (DL-Met) on the laying performance of hens. In exp. 1, a total of 135 forty-seven-wk-old Hy-Line Brown hens were subjected to three dietary treatments for 8 wk: basal diet supplemented with 0.14% L-Lys-HCl and 0.17% DL-Met to satisfy the NRC (1994) total Lys and Met recommendation (control) and basal diet supplemented with encapsulated L-Lys-HCl and DL-Met at the levels of 60% (60CLM, 0.084% L-Lys-HCl and 0.102% DL-Met) or 80% of control (80CLM, 0.112% L-Lys-HCl and 0.136% DL-Met), respectively. In exp. 2, 24 fifty-five-wk-old Hy-Line Brown hens were individually reared in cages and subjected to the same treatments as in exp. 1. The plasma concentrations of free AA and nitrogen metabolites were measured 2, 4, and 6 h after fed. The results showed that dietary AA treatment had no significant influence on body weight (BW), feed intake, laying rate, egg weight, egg mass, or feed efficiency. The expression levels of AA transporters CAT-1, y+LAT1, b0,+AT, B0AT, rBAT, EAAT3, and PepT1 in the duodenum, jejunum, and ileum were not influenced (P > 0.05) by dietary treatment. There was an interaction of dietary AA treatment and time (P < 0.05) and the 80CLM hens exhibited higher concentrations of Lys (P < 0.05) than the controls at 2-h time point. In contrast, plasma Met concentration was not influenced (P > 0.05), while Cys was reduced in the 60CLM hens at every time point. The 80CLM hens had higher taurine concentrations than those receiving the control diet at every postprandial time point. In conclusion, these findings demonstrate that by using encapsulated form, the supplemental levels of synthetic L-Lys-HCl and DL-Met can be effectively reduced by approximately 20% with no negative effect on laying performance. The result suggests that encapsulated Lys and Met may ameliorate the postabsorptive AA balance and contribute to the reduced dietary AA supplemental levels.
研究领域:
动物营养学
·
家禽科学
·
氨基酸代谢
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产品关联
DOI
PubMed
高影响因子
FOOD AND BIOPRODUCTS PROCESSING
·
2023
·
IF 4.6
Yulu Du,Yue Wang,Tianyou Cui,Lianpeng Ge,Fan Yu,Mengqian Zhao,Qihang Xu,Mingjie Jin,Bo Chen,Xuwei Long
Biosurfactant surfactin has a high market value and broad application prospects in the food industry and various industrial fields. However, its production efficiency limits its suitability for real applications. In this study, a new Bacillus subtilis (sp.) 50499 strain was isolated from crude oil-contaminated soil and used to efficiently produce surfactin. The initial surfactin titer was 2.25 g/L after three days of fermentation. Adding 2 g/L of L -Leu significantly improved the titer to over 5.5 g/L after optimizing the culture medium at 37 °C. However, adding D -Leu had the opposite effect on surfactin production , and the surfactin titer dropped to below 0.2 g/L. Furthermore, the product of this strain was analyzed to confirm the identity of surfactin. The surfactin obtained in the present study reduced the surface tension of water to 28.6 mN/m at a critical micelle concentration of 20 mg/L. The emulsification index against n -hexane, corn , and crude oil was as high as over 90%. Hence, the present study provides a newly over-producing strain for surfactin production.
研究领域:
微生物学
·
生物技术
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产品关联
DOI
高影响因子
CELL BIOCHEMISTRY AND BIOPHYSICS
·
2014
·Vol. 71
·期 1
·367-373
·
IF 2.38
Gan Maozhou,Yin Xiaodong
This research designed to explore the antitumor activity of puerarin against human mantle cell lymphoma (MCL). Cell proliferation and apoptosis were assessed by MTS and flow cytometry. Caspase-3, -8, and -9 activities were assessed with the colorimetric caspase protease assay. Apoptotic proteins like PARP, cyclin D1, Bcl-2 family, XIAP, and cIAP I were researched by western blot. The PI3K inhibitor LY294002 was used to investigate the possible mechanism relating the PI3K/Akt signaling pathway. Puerarin in vitro inhibited proliferation and induced apoptosis of Z138 cells. Expressions of PI3K and p-Akt were downregulated by puerarin. Puerarin negatively regulated NF-κB activity by inhibiting NF-κB phosphorylation with nuclear translocation inhibition. This kind of effects was correlated with the suppression of expression of cyclin D1, BAX, Bcl-2, XIAP etc. This function was modulated by the PI3K inhibitor. Our results demonstrated that puerarin can induce growth arrest and apoptosis in MCL cells and that the mechanism may involve the NF-κB signaling pathway. Puerarin may have therapeutic applications in the treatment of MCL.
研究领域:
肿瘤学
·
药理学
·
细胞生物学
·
信号转导
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产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·
IF 4.7
Jing Yang,Jing Shi,Ying Zhou,Ye Zou,Weimin Xu,Xiudong Xia,Daoying Wang
Calcium-binding peptides have gained significant attention due to their potential applications in various fields. In this study, we aimed to prepare, characterize, and evaluate the stability of calcium-binding peptides derived from chicken blood. Chicken hemoglobin peptides (CPs) were obtained by protease hydrolysis and were applied to prepare chicken hemoglobin peptide–calcium chelate (CP-Ca). The preparation conditions were optimized, and the characteristics and stability of CP-Ca were analyzed. The optimal chelating conditions were determined by single-factor and response surface tests, and the maximum calcium ion chelating rate was 77.54%. Amino acid analysis indicated that glutamic acid and aspartic acid motifs played an important role in the chelation of the calcium ions and CP. According to the characterization analysis, CP-Ca was a different substance compared with CP; calcium ions chelated CPs via the sites of carbonyl oxygen, carboxyl oxygen, and amino nitrogen groups; and after the chelation, the structure changed from a smooth homogeneous plate to compact granular. The stability analysis showed that CP-Ca was stable at different temperatures, pH, and gastrointestinal conditions. The study indicates that chicken blood is a promising source of peptide–calcium chelates, providing a theoretical basis for application in functional foods and improving the utilization value of chicken blood.
研究领域:
食品科学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2024
·
IF 2.2
Yucong Song,Mingchuan Pang,Xiaoshu Ding,Guirong Wang,Xinqiang Zhao,Yanji Wang
The solubilities of 2,4-diaminotoluene (2,4-TDA), methyl 3-amino-4-methyl- N -phenyl carbamate (4-TMC) and dimethyl toluene-2,4-dicarbamate (2,4-TDC) in dimethyl carbonate (DMC) and di(2-ethylhexyl) phthalate (DOP) were determined by dynamic method at 298.15 ∼ 398.15 K under atmospheric pressure. The solubility data were correlated by the modified Apelblat equation, polynomial equation and simplified two-parameter equation. The modified Apelblat equation was more accurate than the others. In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy and entropy were calculated by the modified Van't Hoff equation. The dissolution process of 2,4-TDC in DOP solvent is a non-spontaneous entropy reduction endothermic process. The dissolution processes of 2,4-TDA, 4-TMC and 2,4-TDC in DMC solvent and 2,4-TDA and 4-TMC in DOP solvent are all non-spontaneous entropy-increasing endothermic processes.
研究领域:
物理化学
·
材料科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Qingxia Zhou,Yanrong Cheng,Xia Guo
Developing a simple and effective method for detecting and separating amino acids has practical significance. Aqueous two-phase system (ATPS) has the advantages of mild preparation conditions, good stability, and high biocompatibility. In this study, an ATPS exhibiting distinct responses and selectivity profiles toward Phe, Trp, and Tyr was constructed using (1 S , 2 S )-(-)-1,2-diphenylethylenediamine (DPED), sodium dodecyl sulfate (SDS), and sodium carbonate (Na 2 CO 3 ). It is found that the amino acids can trigger the transformation of the DPED/SDS/Na 2 CO 3 ATPS into a single-phase system, but the critical concentrations required for this phase transition vary significantly among the amino acids: Phe and Trp induce the transition at very low concentrations, whereas Tyr requires a much higher concentration (8–13 times greater than Phe and Trp under optimal conditions). This stark contrast enables the DPED/SDS/Na 2 CO 3 ATPS to serve as a sensitive and visually distinguishable platform for differentiating Tyr from Phe and Trp. Moreover, the DPED/SDS/Na 2 CO 3 ATPS exhibits selective phase partitioning: Phe and Trp preferentially concentrate in the top phase, while Tyr predominantly distributes into the bottom phase. This distinct partitioning behavior allows for the efficient separation of Phe and Trp from Tyr, highlighting the system’s dual functionality for both detection and purification of Tyr from Phe and Trp. These findings indicate the potential of using this system to develop methods for separating and detecting the amino acids.
研究领域:
分析化学
·
生物化学
·
分离科学
·
材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Shuai Guo,Lidong Liu,Xin Guo,Tiecheng Liu,Xingcan Li,Guangyu Li
Municipal sewage sludge poses environmental and health risks, and thus, requires proper disposal using pyrolytic techniques. However, these techniques are hindered by the production of NH 3 and HCN (NO x precursors) by the sludge. Hence, a comprehensive understanding of NH 3 and HCN formation during sludge pyrolysis is required to minimize its NO x footprint. As sludge N mainly occurs in proteins forms, its transformations can be modeled using amino acids. Here, we aimed to the study the mechanism by which carbohydrates influence the formation of NO x precursors during sludge protein pyrolysis at different temperatures using glutamic acid , tyrosine, and histidine as protein models and cellulose and lignin as carbohydrate models. During pyrolysis, the release of NH 3 and HCN was promoted by high temperatures and inhibited by carbohydrates. Despite this inhibitory effect, the results suggested that the release of NH 3 should be considered for samples rich in aliphatic amino acids. For glutamic acid and tyrosine, NO x precursor formation was inhibited by N fixation in coke under the action of volatiles produced during carbohydrate pyrolysis. For glutamic acid, adding cellulose and lignin increased the coke-N content by 25.32% and 44.73% at 700 ℃. For histidine, this effect was ascribed to the ring-opening reactions induced by the free radical products of carbohydrate decomposition and the enhanced transfer of N-containing compounds to tar after ring-opening recombination. Further, heterocyclic-N within tar increased to 69.12% due to lignin-histidine interactions at 700 ℃. The results of this study can assist in regulating sludge protein pyrolysis intended for minimizing the production of NO x precursors.
研究领域:
环境科学
·
化学工程
·
废物管理
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产品关联
DOI
高影响因子
TOXICOLOGY AND APPLIED PHARMACOLOGY
·
2023
·
IF 3.8
Yi Zhang,Wenzheng Li,Jun Zhu,Xin Qian,Wenlong Pei,Zhenyang Gu,Qian Wu,Zhan Zhang,Lei Li
Pentachlorophenol (PCP) is a ubiquitous environmental toxicant with various adverse effects. Although its neurotoxicity has been reported, the underlying mechanism and subsequent detoxification remain unclear. In this study, embryos and adult zebrafish were exposed to PCP to determine its potential neurotoxic mechanism and protective indicators. The survival rate, heart rate, mobility time, active status and moving distance were significantly decreased in larvae after 30 μg/L PCP exposure. Likewise, the mobile time, latency to the first movement, velocity and moving distance of adult zebrafish were significantly reduced by PCP exposure. Untargeted metabolomics analysis of larvae revealed that arginine and proline metabolism was the primary pathway affected by PCP exposure, reflected by increased proline and decreased citrulline (CIT) contents, which were confirmed by quantitative data. PCP exposure suppressed the conversion from arginine to CIT in larvae by downregulating the expression of nos1 and nos2a . Ornithine content was increased in the brains and intestines of adult zebrafish after PCP exposure, which inhibited ornithine catabolism to CIT by downregulating otc , resulting in reduced CIT. Intriguingly, CIT supplementation significantly restored the neurobehavioral defects induced by PCP in larvae and adult zebrafish. CIT supplementation upregulated the expression of ef1α and tuba1 in larvae and inhibited the downregulation of ef1α in the brains of adult zebrafish. Taken together, these results indicated that CIT supplementation could protect against PCP-induced neurotoxicity by upregulating the expression of genes involved in neuronal development and function.
研究领域:
毒理学
·
神经科学
·
代谢组学
·
斑马鱼生物学
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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）