Scientific Reports
·
2017
·Vol. 7
·期 1
·1-9
·
IF 4.259
Liu Qingju,Chen Li,Zhang Zhikun,Du Bibai,Xiao Yating,Yang Kunhao,Gong Lingling,Wu Li,Li Xiangjun,He Yujian
D-amino acid oxidases (DAAO) are stereospecific enzymes which are generally almost inactive towards L-enantiomer in neutral solution when L-, D-amino acids are supplied as substrates. In this paper, the D-amino acid oxidase can catalytic oxidize L-amino acids by modulating pH of aqueous solution. With L-Pro as substrate, the catalytic rate ( k
cat ) and the affinity ( K
m ) of DAAO were 6.71 s −1 and 33 mM at pH 8.0, respectively, suggesting that optimal pH condition enhanced the activity of DAAO towards L-Pro. Similar results were obtained when L-Ala (pH 9.8), L-Arg (pH 6.5), L-Phe (pH 9.0), L-Thr (pH 9.4), and L-Val (pH 8.5) were catalyzed by DAAO at various pH values. The racemization of the L-amino acids was not found by capillary electrophoresis analysis during oxidation, and quantification analysis of L-amino acids before and after catalytic reaction was performed, which confirmed that the modulation of enantioselectivity of DAAO resulted from the oxidation of L-amino acids rather than D-amino acids by changing pH. A mechanistic model was proposed to explain enhanced activity of DAAO towards L-amino acids under optimal pH condition.
研究领域:
生物化学
·
酶学
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PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2013
·
IF 2.404
Ming Zhang,De-Jun Chen,Rui-Zhi Wang,Jiu-Ju Feng,Zhengyu Bai,Ai-Jun Wang
Single crystalline flower-like Bi 2 S 3 nanostructures were successfully synthesized via a simple, facile and green hydrothermal method, with the assistance of D -penicillamine. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and found their morphologies mainly depend on the ratios of Bi 3 + to D -penicillamine, as well as the reaction temperature and time. And the possible growth mechanism has been discussed in some detail. In addition, the as-prepared Bi 2 S 3 nanoflowers show good hydrogen storage ability. This strategy can be potentially expanded to prepare other metal chalcogenides materials.
研究领域:
材料科学
·
电化学
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PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-11
·
IF 15.7
Long Haoyu,Zhang Xidong,Zhang Zhenyi,Zhang Jianjun,Yu Jiaguo,Yu Huogen
The H 2 -evolution kinetics play a pivotal role in governing the photocatalytic hydrogen-evolution process. However, achieving precise regulation of the H-adsorption and H-desorption equilibrium (H ads /H des ) still remains a great challenge. Herein, we propose a fine-tuning d - p hybridization strategy to precisely optimize the H ads /H des kinetics in a Ni-B x modified CdS photocatalyst (Ni-B x /CdS). X-ray absorption fine-structure spectroscopy and theoretical calculations reveal that increasing B-atom amount in the Ni-B x cocatalyst gradually strengthens the d - p orbital interaction between Ni 3 d and B 2 p , resulting in a consecutive d -band broadening and controllable d -band center on Ni active sites. The above consecutive d -band optimization allows for precise modulation of the H ads /H des dynamics in the Ni-B x /CdS, ultimately demonstrating a remarkable H 2 -evolution activity of 13.4 mmol g -1 h -1 (AQE = 56.1 %). The femtosecond transient absorption spectroscopy further confirms the rapid electron-transfer dynamics in the Ni-B x /CdS photocatalyst. This work provides insights into the optimal design of prospective H 2 -evolution catalysts.
研究领域:
材料科学
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催化化学
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PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
·
2021
·
IF 2.162
Shu Ye,Fan Zhang,Ying Xu,Yun Sun,Benwei Zhu,Fang Ni,Zhi Zhou,Zhong Yao
In this study, a series of acidic or alkaline polypeptide chains were designed and grafted onto DEG-AM resin using Fmoc solid-phase synthesis to study the relationship between enzyme conformation and carrier surface charge. β-d-glucosidase (βGase) was then immobilized onto these modified carriers by adsorption. Each form of immobilized βGase showed decreasing specific activity compared to that of the free. It could be attributed to both the changes in the enzyme conformation and the decrease in mass transfer efficiency. The optimum temperature of free βGase, DEG@B3-βGase is 55 °C, which of DEG@A3-βGase is 65 °C and they all have the highest activity at pH 5. The Ea values of free βGase, DEG@A3-βGase, and DEG@B3-βGase are 0.546 kJ/mol, 0.224 kJ/mol, and 0.446 kJ/mol, and the Km values were 1.30 mmol/L, 1.44 mmol/L and 2.63 mmol/L, respectively. It shows that free βGase and DEG@A3-βGase are more similar. Meanwhile, the free βGase (1.0 g/L, pH 5.0) stored at 4 °C has a shorter half-life (t1/2), which is only 9 days. However, the half-life of DEG@B3-βGase and DEG@A3-βGase is 20 days and over 60 days, indicating that the negative charged surface was conducive to maintenance of the structure and catalytic property of βGase.
研究领域:
生物化学
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酶工程
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AQUATIC TOXICOLOGY
·
2024
·
IF 4.1
Qi Sun,Jun Dong,Zehui Su,Xuanyun Huang,Xiaoning Gao,Kun Hu,Xiaoling Gong
This study evaluates the impact of environmentally relevant, low-concentration deltamethrin exposure to Eriocheir sinensis ovaries. Our findings revealed that even at a concentration of 0.05 µg/L, deltamethrin exposure can induce significant ovarian toxicity through a 5-day exposure, with gradual amplification detected with time, demonstrating the toxicity amplification effect. Hematoxylin and Eosin staining revealed that low-concentration deltamethrin exposure produces pathological damage consistent with acute toxicity—yolk granules were dissolved and oocyte membranes were ruptured. High-throughput RNA-sequencing data indicated that the acute and low-concentration exposure groups involved completely different pathways and molecular functions, suggesting distinct mechanisms for their toxic effects. Following the identification of phospholipase D (PLD) as a potential core factor regulating the toxicity amplification effect of low concentration deltamethrin, we delved into subsequent mechanism studies using quantitative real-time PCR, immunofluorescence and enzyme-linked immunosorbent assay. Through the GnRH signaling pathway, increased PLD indirectly stimulates augmented estradiol secretion, subsequently inducing apoptosis by upregulating Cathepsin D, which can activate the key executioners of apoptosis—caspases (CASP3 and CASP7). In conclusion, low-concentration deltamethrin exposures can induce significant ovarian damage through apoptosis mediated by the upregulation of PLD in the ovaries of Eriocheir sinensis at environmentally relevant concentrations, which lays the preliminary theoretical groundwork for further elucidating the mechanism of toxicity amplification effect of pesticide exposure at low concentrations.
研究领域:
环境毒理学
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分子生物学
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水生生态学
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PubMed
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2020
·
IF 6.984
Lijuan He,Songping Mo,Pengcheng Lin,Lisi Jia,Ying Chen,Zhengdong Cheng
Sugar alcohols with high latent heat have great potential for medium temperature thermal energy storage . Micro/nano-encapsulation can effectively improve the performance of phase change materials (PCMs), such as avoiding leakage and enhancing thermophysical properties . However, only a few work have been reported on the microencapsulation of sugar alcohol, and the reported methods showed some drawbacks such as requiring strictly controlled reactions or resulting in disability for the capsules to solidify. This paper reports for the first time the synthesis and properties of nanocapsules of a sugar alcohol D-mannitol (DM) by a facile sol-gel method. The nanoencapsulation was confirmed by various characterization using Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), and transmission electron microscope (TEM). Uniform size distribution of the nanoencapsulated DM (NEDM) in 100–200 nm was observed by scanning electron microscope (SEM). The phase change performance of the NEDMs were investigated by differential scanning calorimeter (DSC). The results show that the NEDMs with a melting temperature of 166.2 °C, a melting enthalpy of 220.3 J/g, and an encapsulation ratio of 76.5% were obtained. The thermal reliability of the NEDMs was demonstrated by thermal cycling experiments. The thermal stability of the NEDMs was enhanced compared to DM as investigated by thermogravimetric analyzer (TGA). The NEDMs exhibited great potential for applications in medium temperature thermal energy storage and transfer.
研究领域:
材料科学
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能源工程
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高影响因子
Scientific Reports
·
2020
·Vol. 10
·期 1
·1-12
·
IF 3.998
Wu Yifan,Li Lingtong,Chen Shaopeng,Qin Jun,Chen Xiaolang,Zhou Dengfeng,Wu Hong
Poly( D -lactic acid) (PDLA) with different polyethylene glycol (PEG) segment synthesized PDLA-PEG-PDLA triblock copolymer through the ring-opening reaction of D -LA and PEG will be used as a toughening modifier. The microstructure, crystal structures and crystallization behaviors of this triblock copolymer were investigated by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The triblock copolymer is synthesized from the appearance of CH 2 stretching vibration peak at 2910 cm −1 and C-O stretching vibration peak at 1200 cm −1 from PEG in FTIR spectra. Moreover, the chemical shift that is about 3.6 ppm in 1 H NMR and 68.8ppm in 13 C NMR proves this matter. The results of XRD and DSC reveal that PDLA and PEG are crystallized separately, and are not fully compatible, and microphase separation has occurred in this triblock copolymer. PEG can induce the triblock copolymer to accelerate the rate of crystallization, allowing it to crystallize more completely in the same amount of time. When the molecular weight of PEG is 6000 or the ratio of D -LA/PEG is 1/1, the crystallizability of PDLA-PEG-PDLA triblock copolymer is the best.
研究领域:
材料科学
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高分子化学
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高影响因子
Nano-Micro Letters
·
2023
·Vol. 16
·期 1
·1-18
·
IF 26.6
Li Xudong,Qiang Zhuomin,Han Guokang,Guan Shuyun,Zhao Yang,Lou Shuaifeng,Zhu Yongming
High-entropy catalysts featuring exceptional properties are, in no doubt, playing an increasingly significant role in aprotic lithium-oxygen batteries. Despite extensive effort devoted to tracing the origin of their unparalleled performance, the relationships between multiple active sites and reaction intermediates are still obscure. Here, enlightened by theoretical screening, we tailor a high-entropy perovskite fluoride (KCoMnNiMgZnF 3 -HEC) with various active sites to overcome the limitations of conventional catalysts in redox process. The entropy effect modulates the d -band center and d orbital occupancy of active centers, which optimizes the d – p hybridization between catalytic sites and key intermediates, enabling a moderate adsorption of LiO 2 and thus reinforcing the reaction kinetics. As a result, the Li–O 2 battery with KCoMnNiMgZnF 3 -HEC catalyst delivers a minimal discharge/charge polarization and long-term cycle stability, preceding majority of traditional catalysts reported. These encouraging results provide inspiring insights into the electron manipulation and d orbital structure optimization for advanced electrocatalyst.
研究领域:
材料科学
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电化学
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DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 3
·441
·
IF 4.6
Shuaishuai Cui,Zhaoyang Jin,Tonglin Yu,Cunxin Guo,Yujian He,Yuhe Kan,Liang Yan,Li Wu
The accumulation of D-amino acid-containing peptides is associated with age-related diseases such as Alzheimer’s disease and cataracts, while glycosylation is an important modification of proteins and plays a key role in improving the physicochemical properties of peptides and facilitating their regulation in biological systems. This study investigates the effects of glycosylation position, glycan number, and monosaccharide structure on the conformation and enzymatic degradation of D-amino acid-containing peptides, using KYNEtWRSED (5-t) as a model peptide and six monosaccharides as model glycans. The results demonstrated that glycosylation inhibited the enzymatic degradation of 5-t in the presence of most serine-like proteases. However, in the presence of chymotrypsin, glycosylation with modified monosaccharides (except for β-D-GalNAc) promoted the degradation of 5-t. Furthermore, glycosylation had no effect on the cleavage site of 5-t. Molecular docking analysis revealed that the hydrogen bonding and electrostatic interactions between the glycopeptide and chymotrypsin were markedly strengthened, likely serving as a key determinant of the enzymatic effects. Collectively, these findings highlight the potential of glycosylation to enhance the therapeutic and biomedical applications of D-amino acid-containing peptides in disease treatment and drug design.
研究领域:
生物化学
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分子生物学
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医学
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Yan Li,Jia-Qin Wu,Neng-Bing Long,Rui-Feng Zhang
In this article, novel epoxy resin-based hierarchical porous polymers (HPSs) have been prepared through a non-sol-gel and template-free approach using crystalline trimethylolpropane (TMP) as porogen. The polymers exhibit dimensional stability and possess 3-dimentional interconnected multi-scale pores. In range of 50 μm~10 nm are ultra-macro-pore in between skeleton, macro-pore on skeleton and meso-pore in network, respectively. The porosity and specific surface area can be adjusted in range of 91.2–82.5% and 225–156 m 2 /g, respectively. Using three kinds of hierarchical porous polymers as supports phospholipase D (PLD) was effectively immobilized through physical adsorption. Owing to high porosity of the support and improvement of mass transfer the loading amount of PLD reached as high as 223 mg/g support and the corresponding specific activity achieved up to 3.75 × 10 3 U/g support . Under optimized conditions and the phosphatidylserine (PS) yield reached 95.5% within 40 min at 45 °C. The immobilized PLD exhibited not only better storage stability and but also resistance to pH and thermal inactivation than free PLD. It was found that 73.5% of PS yield retained after 12 cycling reuses.
研究领域:
生物化学
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材料科学
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ANALYTICAL CHEMISTRY
·
2020
·
IF 6.785
Juan Qiao,Han Wu,Huan Wei,Lanqun Mao,Tie Wang,Li Qi
To monitor d-glucose (Glu) in complex aqueous media with a high specificity, a conceptually new “selective capture and controllable detection” nanoreactor was explored. We designed and synthesized poly maleic anhydride-styrene-N-isopropylacrylamide-(4-aminophenyl) boronic acid [P(MAn-St-NIPAm-PBA)] to fabricate the nanoreactor. On the surface of the self-assembled, micelle-based nanoreactor, the stereo precise placement PBA provided a recognition unit in the block copolymer structure to boost the selective capture of Glu over other saccharides. P(MAn-St-NIPAm) served as the thermal sensitive moiety of the nanoreactor, which embedded with glucose oxidase and myoglobin-based catalyst in order to realize the controllable enzymolysis of Glu through temperature alteration. Once the nanoreactor was mixed with Glu, an obvious change in the UV–visible intensity of quinine produced in the multienzymolysis was observed. Glu in the rat microdialysates of brain ischemia was successfully monitored by the nanoreactor method, demonstrating the feasibility of constructing high-specificity nanoreactors for cerebral system applications.
研究领域:
生物化学
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医学工程
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材料科学
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高影响因子
INTERNATIONAL IMMUNOPHARMACOLOGY
·
2025
·
IF 4.7
Shuo Zhang,Shuang Guo,Pengyu Wang,Yan Song,Leiming Yang,Qiyu Sun,Qi Huang,Youzhi Zhang
Background Skeletal muscle atrophy is a clinical concern in diabetic nephropathy, and without effective therapeutic approaches. Massive evidence has demonstrated that dapagliflozin, a sodium-glucose co-transporter 2 inhibitor can relieve diabetic nephropathy by inhibiting glucose re-absorption or podocyte pyroptosis. Nevertheless, whether dapagliflozin could treat skeletal muscle atrophy or the potential protection mechanism in diabetic nephropathy mice is unclear. Methods The variety of approaches were used to assess the particular histology-associated characteristics, mRNA, and protein expression. These included examing the morphology of renal and skeletal muscle tissues through H&E staining, detecting mRNA and protein expression through real-time PCR and Western blot analysis, and monitoring fasting blood glucose levels by using Blood Glucose Monitor Test Kits. Results Dapagliflozin mitigated renal tissue injury with podocyte protein-nephrin and skeletal muscle atrophy effectively with mitochondrial-related proteins. Meanwhile, our research revealed that Casp3 was the target gene and dapagliflozin could decrease the expressions. Subsequently, we verified that dapagliflozin can effectively decrease canonical pyroptosis pathway proteins, which include Gasdermin D, NLRP3, Casp1, and ASC. Meanwhile, Palmitic acid (PA) induced Gasdermin E-N fragment (non-canonical pyroptosis protein) in C2C12 cells, and then released the inflammatory molecules such as IL-1β, IL-18, and NF-kappaB, which were suppressed by dapagliflozin treatment. Aside from that, dapagliflozin demonstrated a good binding affinity to the Casp3 and Gasdermin D protein, whereas it had a less binding affinity with NLRP3, Casp1, ASC, and Gasdermin E. At last, the Gasdermin D inhibitor can reverse the therapeutic effect of dapagliflozin. Conclusion Dapagliflozin alleviates skeletal muscle atrophy in diabetic nephropathy mice, which is through the Gasdermin D-mediated canonical pyroptosis pathway.
研究领域:
医学
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分子生物学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）