JOURNAL OF DAIRY SCIENCE
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2013
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IF 2.566
Liang Li,Ying Ma
The influence of fatty acids on the β-oxidation system and thioesterase of Lactococcus lactis was investigated in this study. The results showed that fatty acids (C8:0–C16:0) significantly inhibited the growth of Lactococcus lactis , and laurate (C12:0) had the highest bactericidal effects. We detected the maximum activity of β-oxidation at different incubation times (8, 12, and 18 h) to be 6.460, 7.751, and 8.203, respectively, and the maximum activity of thioesterase at different incubation times (8, 12, and 18 h) to be 19.498, 27.180, and 12.800, respectively. Fatty acids were seen to induce the β-oxidation system and activity of thioesterase; decanoic acid (C10:0) and palmitic acid (C16:0) were also seen to induce the β-oxidation system of Lactococcus lactis , but the induced ability was significantly different. Octanoic acid (C8:0) and palmitic acid (C16:0) were seen to induce thioesterase activity in Lactococcus lactis . When 1 m M palmitic acid (C16:0) was added to M17 broth, the activity of thioesterase increased 5-fold after 2 min; however, adding octanoic acid (C8:0) changed the activity little. Evidence showed that the ability to induce the β-oxidation system and thioesterase activity was related to the fatty acids’ chain lengths.
研究领域:
微生物学
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生物化学
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DOI
PubMed
高影响因子
TETRAHEDRON
·
2024
·
IF 2.1
Jiahong Chen,Mengke Wang,Weichun Huang,You Zi
A mild and convenient method for synthesizing thioesters has been developed, from sulfenylchlorides and carboxylic acids via a phosphine mediated umpolung process. This approach efficiently produces a broad spectrum of thioesters from readily available carboxylic acids, including primary, secondary, and tertiary types, as well as bioactive molecules. The successful gram-scale reactions also validate its scalability and practical application.
研究领域:
有机化学
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药物化学
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DOI
高影响因子
Catalysts
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2018
·Vol. 8
·期 6
·249
·
IF 3.465
Nani Zhou,Le Shen,Zhen Dong,Jiahong Shen,Lihua Du,Xiping Luo
The preparation of thioesters through the lipase-catalysed transesterification reaction of thiols with vinyl carboxyl esters is described. The reactions were carried out by Lipase TL IM fromThermomyces lanuginosusas a catalyst and performed under a continuous flow microreactor. We first found that lipase TL IM can be used in the reaction of thioester synthesis with high efficiency. Various reaction parameters were investigated including substrate molar ratio, reaction time, and temperature. Maximum conversion (96%) was obtained under the optimal condition of a substrate molar ratio of 1:2 (4-methylbenzyl mercaptan:vinyl esters) at 50 °C for about 30 min. Compared with other methods, the salient features of this work include mild reaction conditions (50 °C), short reaction times (30 min), high yields, and environment-friendliness.Keywords:enzymatic synthesis;thioester synthesis;flow chemistry;microreactor
研究领域:
生物化学
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有机化学
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DOI
高影响因子
JOURNAL OF DAIRY SCIENCE
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2014
·
IF 2.55
Liang Li,Ying Ma
The effects of divalent metal ions (Ca 2+ , Mg 2+ , Fe 2+ , and Cu 2+ ) on the growth, β-oxidation system, and thioesterase activity of Lactococcus lactis were investigated. Different metal ions significantly influenced the growth of L. lactis : Ca 2+ and Fe 2+ accelerated growth, whereas Cu 2+ inhibited growth. Furthermore, Mg 2+ inhibited growth of L. lactis at a low concentration but stimulated growth of L. lactis at a high concentration. The divalent metal ions had significant effects on activity of the 4 key enzymes of the β-oxidation system (acyl-CoA dehydrogenase, enoyl-CoA hydratase, L-3-hydroxyacyl-CoA dehydrogenase, and thiolase) and thioesterase of L. lactis. The activity of acyl-CoA dehydrogenases increased markedly in the presence of Ca 2+ and Mg 2+ , whereas it decreased with 1 mmol/L Fe 2+ or 12 mmol/L Mg 2+ . All the metal ions could induce activity of enoyl-CoA hydratase. In addition, 12 mmol/L Mg 2+ significantly stimulated activity of L-3-hydroxyacyl-CoA dehydrogenase, and all metal ions could induce activity of thiolase, although thiolase activity decreased significantly when 0.05 mmol/L Cu 2+ was added into M17 broth. Inhibition of thioesterase activity by all 4 metal ions could be reversed by 2 mmol/L Ca 2+ . These results help us understand the effect of metal ions on the β-oxidation system and thioesterase activity of Lactococcus lactis .
研究领域:
微生物学
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生物化学
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DOI
PubMed
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
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2015
·Vol. 13
·期 26
·7323-7330
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IF 3.562
Kelu Yan,Daoshan Yang,Wei Wei,Jing Zhao,Yuanyuan Shuai,Laijin Tian,Hua Wang
A novel, efficient, and catalyst-free strategy has been initially developed for the construction of thioesters via the direct radical oxidative decarboxylation of α-keto acids with thiols, and the corresponding target products were obtained in moderate to good yields. It offers an alternative approach for the synthesis of useful diverse thioesters.
研究领域:
有机化学
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合成化学
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产品关联
DOI
PubMed
高影响因子
Nature Communications
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2025
·Vol. 16
·期 1
·1-11
·
IF 15.7
Xia Yanni,Shao Tong,Sun Yue,Wang Jianuo,Gu Chaoyuan,Zhang Chengjian,Zhang Xinghong
The precise placement of thioester bonds into sequence-controlled polymers remains a grand challenge. Here, we demonstrate the versatile synthesis of sequence-controlled polymers from the step polymerization of cyclic thioanhydrides ( A ), diacrylates ( B ), and diols/diamines ( C ). In addition to easily accessible diverse monomers, the method is metal-free/catalyst-free, atom-economical, and wide in monomer scope, yielding 107 polymers with >90% yields and weight-average molecular weights of up to 175.4 kDa. The obtained polymers contain ABAC -type repeating units and precisely distributed in-chain thioester and ester (and amide) groups. The chemoselectivity of the polymerization is revealed by density functional theory calculations. The polymer library exhibits considerably tunable performance: glass-transition temperatures of −36–72 °C, melting temperatures of 43–133 °C, degradability, thermoplastics/elastomers, and thioester-based functions. This study furnishes a facile method to precisely incorporate thioester bonds into sequence-controlled polymers.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
METABOLIC ENGINEERING
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2020
·
IF 7.263
Xi Deng,Liuqing Chen,Mohan Hei,Tiangang Liu,Yan Feng,Guang-Yu Yang
Medium-chain fatty acids (C6–C10) have attracted much attention recently for their unique properties compared to their long-chain counterparts, including low melting points and relatively higher carbon conversion yield. Thioesterase enzymes , which can catalyze the hydrolysis of acyl-ACP (acyl carrier protein) to release free fatty acids (FAs), regulate both overall FA yields and acyl chain length distributions in bacterial and yeast fermentation cultures. These enzymes typically prefer longer chain substrates. Herein, seeking to increase bacterial production of MCFAs, we conducted structure-guided mutational screening of multiple residues in the substrate-binding pocket of the E. coli thioesterase enzyme ‘TesA. Confirming our hypothesis that enhancing substrate selectivity for medium-chain acyl substrates would promote overall MCFA production, we found that replacement of residues lining the bottom of the pocket with more hydrophobic residues strongly promoted the C8 substrate selectivity of ‘TesA. Specifically, two rounds of saturation mutagenesis led to the identification of the ‘TesA RD−2 variant that exhibited a 133-fold increase in selectivity for the C8-ACP substrate as compared to C16-ACP substrate. Moreover, the recombinant expression of this variant in an E. coli strain with a blocked β -oxidation pathway led to a 1030% increase in the in vivo octanoic acid (C8) production titer. When this strain was fermented in a 5-L fed-batch bioreactor , it produced 2.7 g/L of free C8 (45%, molar fraction) and 7.9 g/L of total free FAs, which is the highest-to-date free C8 titer to date reported using the E. coli type II fatty acid synthetic pathway. Thus, reshaping the substrate binding pocket of a bacterial thioesterase enzyme by manipulating the hydrophobicity of multiple residues altered the substrate selectivity and therefore fatty acid product distributions in cells. Our study demonstrates the relevance of this strategy for increasing titers of industrially attractive MCFAs as fermentation products.
研究领域:
生物化学
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合成生物学
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代谢工程
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DOI
PubMed
高影响因子
Journal of Sulfur Chemistry
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2022
·
IF 2.325
Qingqiang Tian,Lili Wang,Yahui Li
A new and convenient copper-catalyzed synthesis of alkyl sulfides has been accomplished using S-alkyl butanethioate as a thiol source. This catalytic protocol displayed a good functional groups tolerance and high efficiency. Both secondary and primary alkyl iodides can be used in this procedure. In addition, this method features operational simplicity and a wide substrate range, providing a complementary method for alkyl sulfide synthesis without requiring toxic thiols and noble metals.
研究领域:
有机化学
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合成化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2020
·
IF 4.335
Shimin Xie,Lebin Su,Min Mo,Wang Zhou,Yongbo Zhou,Jianyu Dong
An alternative thioesterification reaction via copper-catalyzed oxidative coupling of readily available aroylhydrazides with disulfides is developed, in which oxidative expulsion of N2 overcomes the activation barrier between the carboxylic acid derivatives and the products. The reaction produces various thioesters in good to excellent yields with good functional group tolerance. In the reaction, stable and easily available aroylhydrazides are used as acyl sources and the relatively odorless disulfides are used as S sources. Mechanistic investigations demonstrate that the reaction of copper salt and oxidant (NH4)2S2O8 allows for achievement of tandem processes, including deprotonation, free-radical-mediated denitrogenation, and C–S bond formation.
研究领域:
有机化学
·
催化反应
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2021
·
IF 7.46
Yang Mei,Chenxi Li,Si Yang,Wenliang Chen,Rong Liu,Kexin Xu
Since mercury is one of the most toxic heavy metals in water, its detection is critical for environmental protection. Various biosensors based on T-Hg 2+ -T sensing strategies have been developed; however, their mechanisms are highly dependent on the buffer conditions and are not suitable for the rapid high-throughput analysis of many complex water samples. In this work, a self-assembled biosensor for the high-throughput detection of Hg 2+ based on a cleavable PS-RNA-modified probe and homogeneous photochemical chemiluminescence assay was developed. In the presence of Hg 2+ , the probe was cleaved, and the singlet oxygen channel was destroyed, which decreased the fluorescence signal. This biosensor is highly selective for Hg 2+ , with a limit of detection of 1.4 nM (S/N = 3) in a linear range of 5 nM - 5 μM (R 2 = 0.991). The recoveries of standard addition methods in different water samples indicate that this feasible, simple method is a promising tool to monitor mercury ions in environmental applications.
研究领域:
环境科学
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分析化学
·
生物技术
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DOI
高影响因子
Nature Chemical Biology
·
2025
·
IF 13.7
Yao Shunyu,Xie Shengling,Liu Run-Zhou,Huang Zilei,Zhang Lihan
Modular polyketide synthases biosynthesize structurally diverse natural products by a set of catalytic domains that operate in an assembly line fashion. Although extensive research has focused on the rational reprogramming of modular polyketide synthases, little has been attempted to introduce noncanonical catalytic reactions on the assembly line. Here, we demonstrate the insertion of a thioester reductase domain, which can generate a terminal alcohol group instead of the canonical carboxylic acid, onto the assembly line polyketide synthases. We show that the didomain insertion of the acyl carrier protein and thioester reductase pair is generally effective for engineering of various polyketide synthase pathways. As a proof of concept, stereoselective and stereodivergent bioproduction of non-natural diols, namely, 1,3-butanediols and 2-methyl-1,3-butanediols, is achieved by harnessing the modularity of polyketide synthases. Our study expands the catalytic versatility of modular polyketide synthases and paves the way toward biosynthesis of designer alcohols.
研究领域:
合成生物学
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生物化学
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2016
·Vol. 41
·期 1
·271-277
·
IF 3.277
Daoyi Jiang,Qingquan Xue,Zhixiong Liu,Jin Han,Xuedong Wu
Novel nanocomposite (NC) hydrogels based on thiol/acetyl thioester groups chelating with silver nanoparticles (AgNPs) were designed and prepared. The AgNPs acted as both cross-linkers to produce stable NC hydrogels and antimicrobials to prevent the algal adhesion on the surface of hydrogels. The amount of AgNPs embedded in the NC hydrogels had a great influence on the mechanical properties of the NC hydrogels. When the feed molar ratio of the silver element to the sulfur element (Ag/S) approached 0.9, the hydrogels showed the highest mechanical properties. The dynamic nature of the interactions between the AgNPs and thiol/acetyl thioester groups endowed these NC hydrogels with interesting rapid mechanical recovery properties. The NC hydrogels containing thiol groups showed better self-recovery performance than the hydrogels with acetyl thioester groups. In addition, the NC hydrogels with AgNPs exhibited good anti-algal performance for Phaeodactylum tricornutum and Chlorella. When the Ag/S ratio exceeded 0.9, there were almost no algae on the surface of the NC hydrogels. Consequently, these hybrid hydrogels have promising applications in marine antifouling coating and the interfaces of biomaterials.
研究领域:
材料科学
·
生物学
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产品关联
DOI
高影响因子
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