BIOMACROMOLECULES
·
2021
·
IF 6.988
Botuo Zheng,Songyi Xu,Xufeng Ni,Jun Ling
Polymerization of N-substituted glycine N-thiocarboxyanhydrides (NNTAs) is a promising pathway to prepare functional polypeptoids benefiting from their tolerance to nucleophilic impurities. However, controlled NNTA polymerization is hard to achieve in amide polar solvents, including N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), and N-methyl pyrrolidone (NMP), the only aprotic solvents for many biomacromolecules and polypeptoids. In the present work, we successfully achieve controlled NNTA polymerization in amide polar solvents by adding acetic acid as a promoter. The promotion is applied to the polymerization of sarcosine NTA, N-ethyl glycine NTA, and N-butyl glycine NTA. DMAc, DMF, and NMP are suitable solvents to prepare polypeptoids with designable molecular weights and low dispersities (1.06–1.21). The polysarcosines with high molecular weights are prepared up to 35.2 kg/mol. A kinetic investigation quantitatively reveals that the presence of acetic acid not only accelerates the polymerization, but also suppresses H2S-catalyzed decomposition of NNTAs by decreasing the concentration of H2S dissolved in polar solvents. Benzoic acid is also able to promote the polymerization, while trifluoroacetic acid, phosphoric acid, and phenol are not appropriate promoters. The moderate acidity of acids is essential. l-Methionine, l-tryptophan, and l-phenylalanine, which are dissolved in DMF, initiate the controlled polymerization of sarcosine-NTA in the presence of acetic acid and introduce functional end groups to polysarcosines quantitatively. In DMAc, hydrophilic vancomycin is grafted by poly(N-butyl glycine). The amphiphilic product dissolves in dichloromethane and stabilizes water-in-oil emulsion.
研究领域:
高分子化学
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材料科学
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生物技术
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DOI
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Xiaomin Chen,Hui Wang,Xiaojun Huang,Shengkun Xia,Chunhua Chen,Qixing Nie,Shaoping Nie
This work established an effective method for kale flavonoids enrichment by resins. Resin screening, adsorption kinetics and isotherms, dynamic adsorption and desorption tests were conducted to optimize the appropriate resins and enrichment conditions. The results showed that NKA-9 was the optimum resin. The best adsorption conditions were 0.2 mg/mL flavonoids concentration, 12.5 bed volume (BV) sample volume and 2 BV/h adsorption rate. The desorption conditions were 3 BV of 80% ethanol at 2 BV/h elution rate. Under these conditions, the product purity was 31.16%. The purified flavonoids extract was mainly comprised of Kaempferol-3-O-sophoroside-7-O-diglucoside, Kaempferol-3,7,4′-O- d -triglucoside, Kaempferol-3-O-feruloyl-sophoroside-7-O- d -glucoside, and Kaempferol-3-O-sinapoyl-sophoroside. Moreover, it presented higher scavenging ability against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl ( OH) radical than crude extract. In conclusion, kale flavonoids can be well concentrated by NKA-9 resin and the purified flavonoids extract has good antioxidant activity which can be potentially applied in food, cosmetic or pharmacy industries.
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高影响因子
FOOD HYDROCOLLOIDS
·
2018
·
IF 5.089
Xiaoxu Zhu,Linxian Li,Shiyi Li,Cheng Ning,Cunliu Zhou
The effects of l –arginine (Arg) and l –lysine (Lys) on the emulsifying properties of the salt-soluble meat proteins (SSMPs)–soybean oil emulsion (SSOE) and soybean oil–water emulsion (SWE) were evaluated to ascertain their roles in improving the emulsion stability of sausage. The results indicated that Arg/Lys addition or increasing pH increased the emulsifying activity/stability index and the absolute ζ–potential of emulsion droplets but decreased the creaming index, apparent viscosity, and mean particle size of SSOE. Amino acid analysis showed that Arg/Lys accumulated at the interface of the emulsion droplets. Arg/Lys also decreased the surface tension of SWE at 0.002% but increased the stability of SWE at 0.1% – 0.3%. In summary, Arg/Lys improved the stability of emulsified sausage by increasing the electrostatic repulsion of emulsion droplets and decreasing the interfacial tension of soybean oil-water.
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PROTEIN SCIENCE
·
2024
·Vol. 33
·期 10
·e5160
·
IF 4.5
Shuai Xu,Zong-Lin Li,Zhi-Min Li,Hong-Lai Liu
L-cysteine is an essential component in pharmaceutical and agricultural industries, and synthetic biology has made strides in developing new metabolic pathways for its production, particularly in archaea with unique O-phosphoserine sulfhydrylases (OPSS) as key enzymes. In this study, we employed database mining to identify a highly catalytic activity OPSS from Acetobacterium sp. (AsOPSS). However, it was observed that the enzymatic activity of AsOPSS suffered significant feedback inhibition from the product L-cysteine, exhibiting an IC 50 value of merely 1.2 mM. A semi-rational design combined with tunnel analysis strategy was conducted to engineer AsOPSS. The best variant, AsOPSS A218R was achieved, totally eliminating product inhibition without sacrificing catalytic efficiency. Molecular docking and molecular dynamic simulations indicated that the binding conformation of AsOPSS A218R with L-cys was altered, leading to a reduced affinity between L-cysteine and the active pocket. Tunnel analysis revealed that the AsOPSS A218R variant reshaped the landscape of the tunnel, resulting in the construction of a new tunnel. Furthermore, random acceleration molecular dynamics simulation and umbrella sampling simulation demonstrated that the novel tunnel improved the suitability for product release and effectively separated the interference between the product release and substrate binding processes. Finally, more than 45 mM of L-cysteine was produced in vitro within 2 h using the AsOPSS A218R variant. Our findings emphasize the potential for relieving feedback inhibition by artificially generating new product release channels, while also laying an enzymatic foundation for efficient L-cysteine production.
研究领域:
生物化学
·
酶学
·
合成生物学
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PubMed
高影响因子
LANGMUIR
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2021
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IF 3.882
Liang Pan,Guoxi Li,Zhaoyang Wang,Dongbao Liu,Weikang Zhu,Chunyi Tong,Rilong Zhu,Shilin Hu
To reduce the corrosion of Q235 steel, environment-friendly and efficient N-doped carbon dots (N-CDs) were synthesized using 4-amino salicylic acid (4-ASA) and l-histidine (l-His) as precursors. The corrosion inhibition behavior of N-CDs for Q235 steel in 1 M HCl solution was systematically investigated using a weight-loss experiment, an electrochemical test, and corrosion morphology. Results showed that N-CDs could effectively inhibit the corrosion of Q235 steel, and the inhibitory efficiency reached 93% at 50 mg L–1. Quantum chemistry and molecular dynamics were used to study the inhibition mechanism of N-CDs. The results demonstrated that N-CDs exhibited a strong adsorption force on metal and the adsorption process followed the Langmuir adsorption isotherm, indicating physical/chemical mixed adsorption.
研究领域:
材料科学
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环境科学
·
电化学
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DOI
高影响因子
BIOMATERIALS
·
2014
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IF 8.312
Kun Zhang,Hangrong Chen,Faqi Li,Qi Wang,Shuguang Zheng,Huixiong Xu,Ming Ma,Xiaoqing Jia,Yu Chen,Juan Mou,Xia Wang,Jianlin Shi
Aiming at substantially enhanced efficacy and biosafety of clinical HIFU therapy, a natural solid medium, L-menthol (LM), characteristic of mild and controllable “solid-liquid-gas” (SLG) tri-phase transition, was adopted, instead of those conventional explosive liquid–gas (LG) bi-phase transitional media, in constructing a multifunctional theranostic system. Owing to the continuous and controllable characteristics of SLG tri-phase transition, such a novel tri-phase transition-based theranostic system has been demonstrated of the repeatedly enhanced HIFU efficacy ex vivo and in vivo under once intravenous injection and the significantly improved treatment precision, controllability and biosafety when comparing to the traditional bi-phase transition medium, perfluorohexane (PFH), thus promising great application potential in clinical HIFU treatment. Moreover, this theranostic system has been demonstrated a long blood-circulation lifetime and continuous accumulation in tumor in 24 h, which is very beneficial for the enhanced tumor ablation in vivo along with SLG tri-phase transition. More importantly, after loading multiple model drugs and real drug, such a theranostic system presents a HIFU-mediated temperature-responsive drug release property, and depending on the versatile miscibility of LM, co-loadings with hydrophobic and hydrophilic drugs are also achieved, which provides the possibility of synergistic treatment combining HIFU therapy and chemotherapy.
研究领域:
医学影像学
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肿瘤学
·
药剂学
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DOI
高影响因子
ACS Sensors
·
2026
·
IF 10.9
Min Chen,Mengya Li,Guixiang Wang,Rui Han,Zhengya Wang,Mingjing Zou,Hongrun Cui,Xiliang Luo
Nonspecific adsorption remains a persistent obstacle in biosensing applications, as it adversely impacts key performance indicators of biosensors such as sensitivity, specificity, and operational stability. Although conventional antifouling peptides have achieved much success, their practical utility is often constrained by susceptibility to enzymatic hydrolysis as natural enzymes exist in biological fluids. Herein, a robust nonfouling biosensor is proposed based on a newly designed peptide (δ-P) with both antifouling, antienzymatic degradation and recognition capabilities, functionalized with a δ-L-lysinyl-L-glutamic acid dimer. Crucially, the antifouling domain of the peptide is composed of a δ-L-lysinyl-L-glutamic acid dimer (glutamic acid with the lysine side chain), and the recognition domain specific for the protein ANXA1 is composed of D-type amino acids, and both of them are capable of resisting enzymatic degradation. Two types of proteases (alkaline protease and trypsin), which represent less site-specific and site-specific cleavage proteases, respectively, were tested to illustrate proteolysis. Taking advantages of the designed peptide, a highly sensitive and low-fouling electrochemical biosensor (with a linear range of 0.001−1000 ng mL−1 and a detection limit of 0.32 pg mL−1), capable of assaying protein ANXA1 in human sera, was prepared by attaching the peptide onto the electrode modified with a poly(3,4-ethylenedioxythiophene)-sodium alginate (PEDOT@SA) film and gold nanoparticles. More interestingly, the biosensor showed satisfactory accuracy for the detection of ANXA1 in undiluted clinical serum samples (verified by the ELISA method). It is anticipated that the peptide designing strategy presented in this work can be easily extended to the development of various robust antifouling biosensors capable of assaying targets in complex biological environments.
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BIOSENSORS & BIOELECTRONICS
·
2023
·
IF 12.6
Jianfeng Chen,Liyun Ding,Jue Zhao,Xingdong Jiang,Fei Ma,Haijun Li,Yumei Zhang
A surface plasmon resonance (SPR) optical fiber sensor with multimode-coreless-multimode (MNM) structure was developed, which modified by L-glutamine-binding protein (QBP) for detection of L-glutamine (Gln). The QBP was immobilized on the surface of gold films by chemical cross-linking and exhibited a binding affinity for L-glutamine. The conformation of QBP can be changed from the “open” to the “closed”, which led to a red-shift of the SPR peak when QBP bounded to L-glutamine. There was a good linear correlation between is a dependence of the SPR peak on and the concentration of L-glutamine concentration in the range 10–100 μM, with a sensitivity of 10.797nm/log 10 [Gln] for L-glutamine in the in vitro embryo culture (IVC) medium environment, and the limit of detection (LOD) is 1.187 μM. This QBP-modified MNM structure optical fiber SPR sensor provides a new idea for the developmental potential assessment of embryos in the process of in vitro embryo culture.
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PubMed
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JOURNAL OF BIOSCIENCE AND BIOENGINEERING
·
2019
·
IF 2.032
Xiaohong Lu,Juhua Chen,Linshu Jiao,Lei Zhong,Zhaoxin Lu,Chong Zhang,Fengxia Lu
Directed evolution methodologies have been used as promising strategies for improving the catalytic properties of many existing enzymes . In the presented work, this approach was applied to improve the enzyme activity of l -asparaginase I obtained from Bacillus megaterium H-1. After two rounds of error-prone polymerase chain reaction (epPCR) and two generations of sequential DNA shuffling , all of 5 different mutants showed a significant increase in the enzyme activity of l -asparaginase I, ranging from 6.27 to 22.78 IU/mL. Among these mutants, D-9B and DD-12G displayed the relatively high catalytic activity , which were 20.22-fold and 21.33-fold higher than the wild-type enzyme (WT), respectively. Furthermore, the catalytic efficiency ( k cat / K m ) of D-9B and DD-12G were also improved, which were 132.73 min −1 mM −1 and 146.39 min −1 mM −1 , respectively, in comparison to that of WT (3.39 min −1 mM −1 ). In addition, mutant DD-12G showed tolerance toward wider range of pH values and higher temperatures than its WT counterpart. Homology modeling of above two mutants reflected a reduction of hydrogen bonds and an introduction of flexible residues in the loops near the active catalytic site Thr15. These changes contributed to the flexibility of loops, which may lead to further enhancement in catalytic efficiency. Results also showed that approximately 88.5% (0.978 mg/kg) acrylamide could be removed from mutant DD-12G pre-treated fried potato chips. This study clearly shows that directional evolution methods can indeed be utilized to improve the activity of l -asparaginase, which could also provide research basis for future application in food industry.
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JOURNAL OF BIOACTIVE AND COMPATIBLE POLYMERS
·
2017
·
IF 1.31
Fengzhe Wang,Xuan Liu,Longbao Feng,Qiyu Zhu,Shina Yan,Rui Guo
The development of nanomedicine has provided advanced treatment opportunities for many diseases. Simvastatin, a widely used anti-lipidaemic drug, has potential for the treatment of orthopaedic diseases. However, the clinical application of simvastatin is limited because of its hydrophobicity and lack of distribution in osseous tissue. In this study, an amphiphilic nanoparticle, poly(d,l-lactide-co-glycolide)–poly(ethyleneglycol)–poly(d,l-lactide-co-glycolide), was synthesised to improve the biocompatibility of simvastatin. The haemocompatibility of the poly(d,l-lactide-co-glycolide)–poly(ethyleneglycol)–poly(d,l-lactide-co-glycolide) copolymer was investigated through its aggregation, morphology and lysis of human red blood cells, along with its impact on the clotting function according to the activated partial thromboplastin time, prothrombin time and thromboelastographic assays. The results demonstrated that the poly(d,l-lactide-co-glycolide)–poly(ethyleneglycol)–poly(d,l-lactide-co-glycolide) copolymer with a concentration lower than 10 mg/mL had little impact on the aggregation, morphology or lysis of red blood cells, or on blood coagulation. Therefore, the copolymer may be a strong alternative candidate as an effective and safe drug carrier.
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WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2025
·Vol. 42
·期 1
·22
·
IF 4.2
Zhang Jia-Bao,Yang Yong-Jun,Liu Zhen-Zhen
Lactobacillus gallinarum Y86, isolated from broiler ileal mucosa under strict anaerobiosis (85% N₂/10% CO₂/5% H₂), demonstrates significant potential as a microbial feed additive for antibiotic-free farming. 16 S rRNA sequencing (99.79% identity to L. gallinarum ATCC 33199; GenBank ON248243) confirmed its taxonomy. Stationary-phase cultures secreted a heat-stable antimicrobial that produced inhibition zones of 21.53 ± 0.34 mm against Salmonella enterica serovar pullorum and 11.90 ± 0.52 mm against Staphylococcus aureus , retaining 87.30% activity after 120 °C for 15 min; sensitivity to trypsin and lipase indicates a proteolipid nature. Y86 endured pH 2.0 for 3 h (63.37% survival) before programmed lysis at 4 h, then recovered to 92.44% viability under intestinal conditions and maintained 45.36% viability in 0.5% bile. High surface hydrophobicity (85.71%) drove auto-aggregation to 97.99% within 24 h, supporting strong epithelial adhesion. The strain was susceptible to β-lactams, macrolides, and vancomycin, intrinsically resistant to tetracyclines and quinolones, and non-haemolytic, meeting EFSA-QPS safety criteria. Collectively, its thermostable antimicrobial production, timed gastric lysis, intestinal resilience, and proven safety identify Y86 as an industrially compatible candidate for antibiotic-free poultry feeds, advancing microbiota-based alternatives to growth-promoting antibiotics.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Yuxia Zhu,Xiaopu Ren,Yingjie Bao,Shun Li,Zengqi Peng,Yawei Zhang,Guanghong Zhou
Hypothesis Eggplant is rich in polysaccharides . The mechanically homogenized eggplant flesh pulp (EFP) is expected to emulsify and stabilize o/w emulsions. The adsorption and network structure of the polysaccharides are hypothesized to contribute to the stability of emulsions . Experiments Creaming index (CI) and droplet size distribution were observed to evaluate the stabilities of EFP emulsions at different EFP concentrations (0.50, 0.75, 1.00, 1.25 and 1.50% w/v). Optical and fluorescence microscopy, confocal laser scanning microscopy and cryogenic scanning electron microscopy were conducted to observe the emulsification properties of the EFP-stabilized emulsions. In addition, rheological measurements were performed to reveal the EFP emulsions’ rheological behaviours. Findings The prepared oil-in-water emulsion emulsified by EFP remained stable at an EFP concentration of 1.50%. Rheological analysis illustrated that the emulsions had typical shear-thinning property and gel-like nature. The emulsification mechanisms were explained by the formation of an interfacial film adhered to the oil droplets and the coherent three-dimensional network formed by filament and sheet-like polysaccharide strands in the continuous phase. This finding may define a new kind of natural and dietary emulsifier for emulsion-based food, beverage, and pharmaceutical products.
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