TRANSACTIONS OF TIANJIN UNIVERSITY
·
2018
·Vol. 24
·期 6
·513-521
·
IF 0
Shan Yuyao,Qi Wei,Wang Mengfan,Su Rongxin,He Zhimin
Recently, enzymatic peptide synthesis has drawn increasing attention due to its eco-friendly reagents and mild conditions, as compared to traditional chemical peptide synthesis. In this study, we successfully produced an important antioxidant dipeptide precursor, BOC-Tyr-Ala, via a kinetically controlled enzymatic peptide synthesis reaction, catalyzed by the recombinant carboxypeptidase Y (CPY) expressed in P. pastoris GS115. In this reaction, the enzyme activity was 95.043 U/mL, and we used t -butyloxycarbonyl- l -tyrosine-methyl ester (BOC-Tyr-OMe) as the acyl donor and l -alanine ( l -Ala) was the amino donor. We optimized the reaction conditions to be: 30 °C, pH 9.5, organic phase (methanol)/aqueous phase = 1:20, BOC-Tyr-OMe 0.05 mol/L, Ala 0.5 mol/L, and a reaction time of 12 h. Under these conditions, the dipeptide yield reached 49.84%. Then, we established the kinetic model of the synthesis reaction in the form of Michaelis–Menten equation according to the concentration–time curve during the process and the transpeptidation mechanism. We calculated the apparent Michaelis constant \(K_{\text{m}}^{\text{app}}\) and the apparent maximum reaction rate \(r_{\hbox{max} }^{\text{app}}\) to be \(2.9946 \times 10^{{^{ - 2} }} {\text{ mol/L}}\) and \(2.0406 \times 10^{ - 2} {\text{ mmol/(mL}}\,{\text{h)}}\) , respectively.
研究领域:
生物技术
·
酶学
·
肽化学
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DOI
CELL BIOLOGY AND TOXICOLOGY
·
2025
·Vol. 41
·期 1
·1-22
·
IF 5.9
Meng Xinyue,Wei Xiaowei,Gu Hui,Ma Wei,Liu Dan,Jia Shanshan,Cao Songying,Ding Dongxue,He Yiwen,Huang Wanqi,Xue Jia,Luo Wenting,Sun Wei,Yuan Zhengwei
Duodenal atresia (DA) is a common neonatal digestive tract obstruction, with unclear prenatal diagnostic specificity and optimal intervention timing. tRNA-derived small RNAs (tsRNAs), stable and enriched in blood, are promising biomarkers for disease diagnosis. Therefore, identifying tsRNA biomarkers, elucidating DA pathogenesis, and exploring potential intrauterine interventions is urgently needed. This study conducts tsRNA profiling via sequencing on plasma samples from pregnant women carrying fetuses with DA and matched healthy controls. Validation was performed in 147 pregnant women, including cohorts with fetal gastrointestinal atresia, normal pregnancies, and post-delivery cases. Functional analyses in cellular models and Adriamycin rat models with DA explored the role of key tsRNAs in DA pathogenesis and intrauterine therapy. It is found that tsRNAs, including tRF-61:78-chrM. Leu-TAA, tRF-60:77-Ile-AAT-1-M4, tRF-57:76-Arg-ACG-1-M2, and tRF-58:76-Tyr-GTA-2-M3, were significantly downregulated in DA cases. tRF-58:76-Tyr-GTA-2-M3 is further implicated in DA development, with knockdown inducing excessive apoptosis via upregulation of SUFU and suppression of GLI1, a hedgehog pathway transcription factor. Intraperitoneal microinjection of tRF-58:76-Tyr-GTA-2-M3 agomir in DA rat models reduce apoptosis and mitigates DA formation by modulating SUFU and GLI1 expression. Taken together, this study identifies novel tsRNA biomarkers for DA, with tRF-58:76-Tyr-GTA-2-M3 playing a pivotal role in its pathogenesis. These findings offer insights into DA mechanisms and suggest potential therapeutic targets, advancing strategies for early diagnosis and intervention.
研究领域:
医学
·
分子生物学
·
产前诊断
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Di Liu,Yunning Chen,Renquan Guan,Jie Zhao,Huimin Jin,Siyi Zhang,Qingkun Shang
In this paper, a type of heterojunction photocatalyst S-Tyr-NDI-Tyr/TiO 2 was prepared by self-assembly of tyrosine-substituted naphthamide (NDA) and bonding with titanium dioxide. The self-assembly process and driving force of monomer M-Tyr-NDI-Tyr were simulated by theoretical calculation. Taking atenolol as the target pollutant, the photocatalytic performance of the heterojunction photocatalyst under visible light was studied, and the degradation products were analyzed by mass spectrometry. The environmental toxicity of photocatalytic process was evaluated by luminescent bacteria. The principle of high photocatalytic activity of S-Tyr-NDI-Tyr/TiO 2 heterojunction photocatalyst was proposed by analyzing the fluorescence spectrum, photocurrent density and resistance, electron paramagnetic resonance spectrum, free radical capture experiment and energy band position of S-Tyr-NDI-Tyr/TiO 2 heterojunction photocatalyst. In addition, the photocatalytic degradation of different pollutants by S-Tyr-NDI-Tyr/TiO 2 heterojunction photocatalyst was also studied. This work will provide a useful example for the further development of new and efficient organic supramolecular/inorganic semiconductor composite photocatalysts.
研究领域:
材料科学
·
环境科学
·
化学
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DOI
PubMed
高影响因子
Energies
·
2024
·Vol. 17
·期 13
·3195
·
IF 3
WenLong Gao,LiWei Sun,Miao Li,XiAn Ye,QingChun Gao,DongLiang Kong,JunPu An,KuoBo Wang,Fan Yang
This paper focuses on the selection and application of scale inhibitor by studying the problem of pipeline scaling in geothermal well development. Adding scale inhibitor can effectively reduce the treatment cost and achieve a good scale resistance effect, but the commonly used polyaspartic acid scale inhibitor has problems such as poor scale inhibition effect and large use limitations. Therefore, a new modified polyaspartic acid scale inhibitor (His-Tyr-SA-PASP) was prepared using polysuccinimide (PSI) as the raw material and histidine (His), tyrosine (Tyr), and sulfonic acid (SA) as the modification reagent. When the dosage of His-Tyr-SA-PASP was 8 mg/L, the scale inhibition rate of CaCO3was 94.40%. In addition, the scale inhibition effect of His-Tyr-SA-PASP on CaCO3was better than that of PASP. At the same time, under the condition of a static experiment at 75 °C, according to the ion concentration of water samples in different scale zones, this paper also identified the ratio of four composite scale inhibitors. When the dosage of compound scale inhibitor was 100 mg/L, Sodium of Polyaspartic Acid–Diethylene Triamine Penta (Methylene Phosphonic Acid)–2-Phosphonobutane-1,2,4-Tricarboxylic Acid–Amino Trimethylene Phosphonic Acid–Copolymer of Maleic and Acrylic Acid = (10:10:5:1:9), (15:10:5:2.5:2.5), (12.5:5:10:1:6.5), and (15:5:10:4:1) and the scale inhibition rate was more than 95%. Under the condition of a dynamic experiment, the optimized composite scale inhibitor still showed a scale inhibition rate of more than 90%. It provides a useful reference for the practical application of water treatment in geothermal wells and has the prospect of industrial application.
研究领域:
化学工程
·
材料科学
·
环境科学
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DOI
高影响因子
iScience
·
2023
·Vol. 26
·期 7
·107048-107048
·
IF 5.8
Li Li,Zuxian Xu,Ruipin Cao,Jiaxin Li,Chang-Jer Wu,Yinglu Wang,Hu Zhu
We investigated the influence of hydroxyl groups on the anti-quorum-sensing (anti-QS) and anti-biofilm activity of structurally similar cyclic dipeptides, namely cyclo( L -Pro- L -Tyr), cyclo( L -Hyp- L -Tyr), and cyclo( L -Pro- L -Phe), against Pseudomonas aeruginosa PAO1. Cyclo( L -Pro- L -Phe), lacking hydroxyl groups, displayed higher virulence factor inhibition and cytotoxicity, but showed less inhibitory ability in biofilm formation. Cyclo( L -Pro- L -Tyr) and cyclo( L -Hyp- L -Tyr) suppressed genes in both the las and rh l systems, whereas cyclo( L -Pro- L -Phe) mainly downregulated rhl I and pqs R expression. These cyclic dipeptides interacted with the QS-related protein LasR, with similar binding efficiency to the autoinducer 3OC12-HSL, except for cyclo( L -Pro- L -Phe) which had lower affinity. In addition, the introduction of hydroxyl groups significantly improved the self-assembly ability of these peptides. Both cyclo( L -Pro- L -Tyr) and cyclo( L -Hyp- L -Tyr) formed assembly particles at the highest tested concentration. The findings revealed the structure-function relationship of this kind of cyclic dipeptides and provided basis for our follow-up research in the design and modification of anti-QS compounds.
研究领域:
微生物学
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药理学
·
分子生物学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Xiao-Peng Liu,Wen-Shu Zhang,Ya-Ning Wang,Wen-Qi Ye,Zhang-Run Xu
Psoralen ultraviolet A (PUVA) therapy has thrived as a promising treatment for psoriasis. However, overdose of PUVA treatment will cause side-effects, such as melanoma formation. And these side-effects are often ignored during PUVA therapy. Hence, in situ monitoring therapeutic response of PUVA therapy is important to minimize side-effects. Aberrant expression of tyrosinase (TYR) has been proved to be associated with melanoma, indicating that TYR is a potential target for evaluation of PUVA therapy. Herein, we reported a strategy for in situ monitoring TYR activity during PUVA therapy by using a cell-array chip-based SERS platform. The cell-array chip was used to simulate cell survival environment for cell culture . Capture of single cells and living cell analysis were realized in the isolated microchambers. An enzyme-induced core-shell self-assembly substrate was used to evaluate TYR activity in living cells during PUVA therapy. The gold nanoparticle modified with a SERS reporter, 4-mercaptobenzonitrile (4-MBN), was used as the core. In the presence of oxygen and TYR, hydroxylation of l -tyrosine occurred, leading to the reduction of silver ion on the surface of gold cores. The growth of silver shells was accompanied by the increased SERS intensity of the reporter, which is related directly to TYR activity. The detection limit for TYR activity is 0.45 U/mL. Upregulation of TYR activity was successfully monitored after PUVA therapy. Notably, real-time and in situ information of therapeutic response can be obtained through monitoring PUVA therapy by using a cell-array chip-based SERS platform, which has great potential to guide the clinical application of PUVA therapy.
研究领域:
生物医学工程
·
皮肤病学
·
治疗监测
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DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Minling Li,Dechan Lu,Ruiyun You,Huiying Shen,Lanjin Zhu,Qingqiang Lin,Yudong Lu
Tyrosinase (TYR) is a key rate-limiting enzyme of melanin and a biomarker for melanoma diagnosis. Therefore, detection of TYR in biological samples is essential for the clinical diagnosis of melanoma. A novel portable surface-enhanced Raman scattering (SERS) sensor is proposed to detect TYR activity. It is based on dopamine (DA)-functionalized Au nanorod (Au NR) arrays as the capture substrate and 4-mercaptophenylboronic acid (4-MPBA)-modified silver nanoparticles (Ag NPs) as the SERS probe. In this case, the Au NR arrays are modified with 3,3′-dithiodipropionic acid di(N-succinimide ester) (DSP) to capture DA. In the presence of TYR, DA is oxidized to dopaquinone (DQ), which resulted in a decrease in the concentration of SERS probes further adsorbed onto the arrays. The activity of TYR is detected by changes in the intensity of the phenylboronic acid signal. Furthermore, this detection system has a wide linear detection range and high sensitivity that can effortlessly evaluate a linear range of 0.0001–100 U/mL of TYR activity. More significantly, the presented SERS sensor can perform well on both the determination of TYR activity in serum and the assessment of TYR inhibitors, which offers new opportunities for diagnosis of melanoma and other TYR-related diseases under complex biological conditions.
研究领域:
生物医学工程
·
分析化学
·
纳米技术
·
癌症诊断
·
分子生物学
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产品关联
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Wenyu Wei,Dongfang Li,Xiangdong Cai,Zhao Liu,Zhongtian Bai,Jianxi Xiao
The construction of potent peptide probes for selectively detecting denatured collagen is crucial for a variety of widespread diseases. However, all of the denatured collagen-targeting peptide probes found till date primarily utilized the repetitive (Gly-X-Y)n sequences with exclusively imino acids Pro and Hyp in the X and Y positions, which stabilized the triple helical conformation of the peptide probes, resulting in severe obstacles for their clinical applications. A novel series of peptide probes have been constructed by incorporating nonimino acids at the X position of the (GPO)3GXO(GPO)4 sequence, while the X-site residue is varied as Tyr, Phe, Asp, and Ala, respectively. Peptide probes FAM-GYO and FAM-GFO containing aromatic residues Tyr and Phe at the X position showed similarly high binding affinity and tissue-staining efficacy as the well-established peptide probe FAM-GPO, while peptide probes FAM-GDO and FAM-GAO with the corresponding charged residue Asp and the hydrophobic residue Ala indicated much weaker binding affinity and tissue-staining capability. Furthermore, FAM-GYO and FAM-GFO could specifically detect denatured collagen in different types of mouse connective tissues and efficiently stain various human pathological tissues. We have revealed for the first time that the incorporation of nonimino acids, particularly aromatic residues at the X and Y positions of the repetitive (Gly-X-Y)n sequences, may provide a convenient strategy to create novel robust collagen-targeting peptide probes, which have promising diagnostic applications in collagen-involved diseases.
研究领域:
生物化学
·
分子生物学
·
病理学
·
医学诊断
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产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Huan Li,Yingying Li,Yudan Wang,Lijia Liu,Hongxing Dong,Chunhong Zhang,Toshifumi Satoh
Flexible and self-healing conductive hydrogel, as a typical electronic skin with the function of transmitting sensory signals, has attracted remarkable attentions in the biomaterials field. However, the practical application of electronic skin has been severely limited owing to the potential bacterial infection threats. Here, in order to improve the antibacterial properties of electronic skin, a star-shaped polyetheramide (Tyr-PEAm) derived from L-tyrosine was synthesized and cross-linked into the hydrogel network. A compliant and self-healing conductive hydrogel (defined as PVA/PDA/Tyr-PEAm) was assembled from polyvinyl alcohol (PVA), polydopamine (PDA) and Tyr-PEAm. The hydrogel achieved a comprehensive performance of long-term antibacterial activity (the inhibition zones remained unchanged over 7 days), low hemolysis activity (hemolysis rate of 0.042 %), good conductivity and rapid self-healing ability (healing within 1 s). Therefore, the hydrogel could be used not only as a detection device to check normal skin, but also as the wound skin detection in real time. Furthermore, the good conductivity and rapid self-healing ability contributed to the hydrogel to detect various macro and micro movements of the human body, as well as to recycle as a new sensor. The PVA/PDA/Tyr-PEAm hydrogel that integrated intelligent signals and resisted bacterial infections exhibited broad application prospects in biomedical materials.
研究领域:
生物材料学
·
医学工程
·
材料科学
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产品关联
DOI
高影响因子
ACS Omega
·
2026
·Vol. 11
·期 35
·53469-53476
·
IF 5.2
Lu Xin,Yuan Fangfang,Han Xiaojie,Qin Tingting,Wang Qianqian,Li Zengli,Ge Chuanjun,Shi Wenqing,Bai Haijiao,Wang Pei
Desmopressin, a synthetic
analog of vasopressin widely used in
the treatment of diabetes insipidus and bleeding disorders, is a representative
disulfide-containing peptide therapeutic prepared by Fmoc-based solid-phase
peptide synthesis (SPPS). Its unique sequence architecture, particularly
the spatial proximity between the N-terminal mercaptopropionic acid
residue Mpa(1) and the Tyr(2) residue, provides a distinct structural
environment for investigating sequence-dependent side reactions during
peptide manufacturing. The tert- butyl ( t- Bu) protecting group is widely employed for side-chain protection
in Fmoc-based solid-phase peptide synthesis (SPPS). However, under
certain reaction conditions, the highly reactive t- Bu + carbocation generated during acidic deprotection can
participate in nonspecific alkylation, leading to challenging process-related
impurities. In this study, we investigated a unique and highly site-selective
+56 Da impurity observed during side-chain deprotection. High-resolution
MS/MS analysis unambiguously identified this species as a site-selective
product arising from the migration of t- Bu from the
Tyr(2) side chain to the thiol group of Mpa(1). Based on the structural
features of desmopressin, in particular, the spatial proximity between
Tyr(2) and Mpa(1), we propose that the formation of this impurity
most plausibly proceeds via a vicinal-thiol-induced intramolecular
migration mechanism, which competes significantly with the conventional
diffusion-controlled carbocation intermediate intermolecular pathway.
Strengthening the scavenger conditions failed to eliminate this impurity,
further supporting the intramolecular migration mechanism induced
by vicinal thiol. This finding accounts for the observed site selectivity
that cannot be explained by the conventional carbocation intermediate
pathway alone. Guided by these mechanistic insights, we re-evaluated
the necessity of Tyr side-chain protection and proposed a “source-elimination”
strategy. Experimental validation demonstrated that the use of unprotected
Fmoc-Tyr-OH (free phenolic hydroxyl) completely suppressed the formation
of the t- Bu migration impurity and improved the crude
peptide purity to 93.5%. Overall, this study elucidates the formation
mechanism of t- Bu migration impurities and provides
a broadly applicable, mechanism-driven strategy for process optimization
in solid-phase peptide synthesis. While this study focuses on the
desmopressin system, the findings highlight a proximity-driven reactivity
pattern that may be relevant to other thiol-containing peptide sequences.
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DOI
高影响因子
Frontiers in Nutrition
·
2022
·
IF 6.59
Hui Jiang,Fei Wu,Xi Jiang,Yun-Feng Pu,Li-Rong Shen,Cui-Yun Wu,Hong-Jin Bai
Pear is one of the most popular fruits in the world. With the fruit ripening, a series of physiological changes have taken place in fragrant pear, but up to now, the research on the metabolism and biological activity of phenolic compounds in different growth stages of fragrant pear is still lacking. In this study, four kinds of Xinjiang pears were selected as research objects, and the changes of phenolic content, antioxidant capacity, cell protection and whitening activity during fruit development were analyzed. The results showed that the phenolic content and antioxidant capacity of four pear varieties presented a decreasing trend throughout the developmental stages. The phenolic content and antioxidant activity of the four pears in the young fruit stage were the highest, and the active ingredients of the Nanguo pear were higher than the other three pear fruits. Pear extract could protect cells by eliminating excessive ROS in cells, especially in young fruit stage. The western blot results showed that the extract of fragrant pear in the young fruit stage could inhibit the expression of TYR, TYR1 and MITF in B16 cells, and it was speculated that the extract of fragrant pear in the young fruit stage might have good whitening activity. Therefore, the findings suggest that young pear display a good antioxidant potential and could have a good application prospect in food preservation and health product industry.
研究领域:
食品科学
·
药理学
·
植物生理学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
PROCESS BIOCHEMISTRY
·
2021
·
IF 3.757
Yonghua Hu,Yuan Zhou,Xiaohua Hu,Qiaoling Chen,Yan Shi,Jiangxing Zhuang,Qin Wang
Cefotaxime sodium (CTX) was found to inhibit the activity of mushroom tyrosinase. The present study was conducted to investigate its inhibition of melanogenesis in B16F10 cells. CTX was found to inhibit melanin synthesis in B16F10 cells at a concentrations less than 200 μmol/L with no cytotoxicity. CTX reduced tyrosinase activity in a dose-dependent manner. CTX inhibited melanin formation from the results of the Masson-Fontana melanin staining and transmission electron microscope CTX influenced melanin production by influencing the expression of the proteins MITF, TRP-1, TRP-2 and TYR. Furthermore, CTX could down-regulate the intracellular cAMP/PKA/CREB contents, affecting the expression of MITF, and further down-regulate the expression of TRP-1, TRP-2 and TYR to inhibit melanin. Furthermore, CTX has been shown to inhibit body pigmentation in zebrafish. These results may provide a theoretical foundation for the new application of CTX in the field of medicine.
研究领域:
药理学
·
细胞生物学
·
分子生物学
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DOI
高影响因子
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