PROCESS BIOCHEMISTRY
·
2024
·
IF 3.7
Shaoyang Zhang,Guorong Zhu,Zhixiang Pan,Yi Wei,Zuoming Nie,Qing Sheng,Zhongyi Yang
L-threo-methylsulonylphenylserine (L-threo-MSPS) is a crucial intermediate in florphenicol and thiamphenicol synthesis. L-threo-MSPS can be synthesized from L-threonine and p-methylsulfonylbenzaldehyde (p-MSBA) chiral selectively under the catalyse of L-threonine transaldolase . However, the byproduct acetaldehyde formed during the reaction process severely hinders the biosynthesis of high-quality L-threo-MSPS. The accumulated acetaldehyde reacts with L-thero-MSPS and L-threonine to form N-derivatives, and the activity of L-threonine transaldolase decreases to 14.10% even when the concentration of acetaldehyde is as low as 0.5 g/L. The acetaldehyde could be removed by aeration, and the removal efficiency is closely related to the aeration conditions, which was described by the volumetric oxygen transfer coefficient k L a in this paper. Regular aeration through pipes cannot provide enough aeration efficiency, and filters or sintered rods were used to increase the k L a value during the reaction. The residual concentration of acetaldehyde depended on the balance between the formation and removal speed of acetaldehyde. When the optimal enzyme concentration was applied and the k L a value of 5.5 min -1 , the L-threo-MSPS concentration reached 293.28 mM in a 1-L reaction, and the highest conversion reached 90.03%. The need of coenzyme NAD + was cut off in this method, and only one enzyme was applied. Consequently, the reaction was simpler and easier to control.
研究领域:
生物化学
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制药工程
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Hang Su,Shuo Huang,Xin Gao,He Bai,Haopeng Zhang,Long Li,Lei Zhao,Hongyan Yue
Highly efficient recognition and detection of chiral molecules with similar structures are of great significance in the fields of medicine and biochemistry. In this study, strobili fibers of the plane tree were carbonized at high temperatures to prepare hollow chiral helical carbon tubes (HCT). Subsequently, l-threonine (l-Thr) was nanoassembled on the HCT surface (l-Thr@HCT) through hydrogen bonding and electrostatic interactions. Benefiting from the synergistic effect of conductive HCT with inherent chirality and l-Thr with abundant chiral sites, the electrode demonstrates a satisfied recognition efficiency of 3.20 for the cysteine (Cys) enantiomer. The l-Thr@HCT/GCE electrode exhibits a lower affinity toward l-Cys than d-Cys, thereby facilitating the diffusion of l-Cys to the electrode surface and exhibiting excellent selectivity for l-Cys. Under the optimal conditions, the electrode has a high sensitivity of 1.74 μA·mM–1 for l-Cys with a low detection limit of 8.58 μM (S/N = 3). Moreover, the electrode has good repeatability, reproducibility, and stability. This electrode will have a potential clinical application in chiral sensing.
研究领域:
生物医学工程
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分析化学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2025
·
IF 9
Xin Jin,Sumeng Wang,Yaping Gao,Qingsheng Qi,Quanfeng Liang
Background The industrial production of L-threonine faces challenges because of high production costs, especially those of substrates, meaning new production methods are needed. Methods Fur, a new global transcription factor related to L-threonine biosynthesis, was discovered in this study. Multidimensional regulation combined with global transcriptional machinery engineering was used to modify an Escherichia coli strain. Results: The most efficient mutant showed high titer (154.2 g/L), productivity (2.14 g/L/h), and yield (0.76 g/g) of L-threonine production. These three parameters indicated that these engineering strategies were economically feasible for developing high L-threonine-producing strains. We integrated the sucrose utilization gene cluster into the genome to further reduce the production cost of L-threonine. Using untreated cane molasses as the substrate, L-threonine was successfully produced with a titer of 92.46 g/L and a cost reduction of 48 %. Conclusion This research offers advantages for industrial scalability, and the resulting engineered bacterium holds significant industrial application potential.
研究领域:
生物工程
·
微生物学
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产品关联
DOI
PubMed
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2016
·Vol. 358
·期 18
·2923-2928
·
IF 6.453
Peiyuan Yao,Yunfeng Cui,Shanshan Yu,Yuncheng Du,Jinhui Feng,Qiaqing Wu,Dunming Zhu
An efficient multi-enzyme cascade reaction for the synthesis of ( R )- or ( S )-2-hydroxybutyric acid [( R )- or ( S )-2-HB] from l -threonine was developed by using recombinant Escherichia coli cells expressing separately or co-expressing l -threonine deaminase from Escherichia coli K-12 ( ilvA ), formate dehydrogenase (FDH) from Candida boidinii and l -lactate dehydrogenase ( l -LDH) from Oryctolagus cuniculus or d -lactate dehydrogenase ( d -LDH) from Staphylococcus epidermidis ATCC 12228. Up to 750 mM of l -threonine were completely transformed to ( R )- or ( S )-2-HB in optically pure form (>99% ee ) with high isolated yields. This one-pot multi-enzyme transformation provides a new practical method for the synthesis of these important optically pure compounds.
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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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 28
·期 4
·4262-4275
·
IF 3.056
Li Chao,Luo Miaomiao,Zhou Shihua,He Hanyue,Cao Jiashun,Luo Jingyang
l -Threonine and three kinds of conductive polymers were applied for anode modification in microbial fuel cells (MFCs) for decolorization of Congo red with simultaneous electricity generation. The description of modified anodes with FTIR, surface contact angle, and CV analysis showed that the anode surface was successfully grafted with functional groups, with improving wettability, as well as the increasing specific surface area and electrochemical activity. For l -threonine modification, the highest decolorization rate of 97% of the MFC, and meanwhile, the maximum current density of 155.8 mA/m 2 , was obtained at the modified concentration of 400 mg/L. For conductive polymer modifications, the poly (aniline-1,8-diaminonaphthalene) (short for PANDAN) owned the highest performance, with the current density 185 mA/m 2 , and the decolorization rate was 97%. Compared with l -threonine, the modifications by conductive polymers were more suitable for MFC decolorization due to their functional groups and unique conductivity. In addition, high-throughput sequencing analysis was conducted for the conductive polymers modified anodes to reveal their bioelectrochemical mechanisms.
研究领域:
环境科学
·
生物化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Zhenqiang Zhao,Jiajia You,Xuanping Shi,Rongshuai Zhu,Fengyu Yang,Meijuan Xu,Minglong Shao,Rongzhen Zhang,Youxi Zhao,Zhiming Rao
Exploring effective remodeling strategies to further improve the productivity of high-yield strains is the goal of biomanufacturing. However, the lack of insight into host-specific metabolic networks prevents timely identification of useful engineering targets. Here, multidimensional engineering strategies were implemented to optimize the global metabolic network for improving l-threonine production. First, the metabolic bottleneck for l-threonine synthesis was eliminated by synergistic utilization of NADH and an enhanced ATP supply. Carbon fluxes were redistributed into the TCA cycle by rationally regulating the GltA activity. Subsequently, the stress global response regulator UspA was identified to enhance l-threonine production by a transcriptomic analysis. Then, l-threonine productivity was improved by enhancing the host’s stress resistance and releasing the inhibitory reaction of glucose utilization. Eventually, the l-threonine yield of THRH16 reached 170.3 g/L and 3.78 g/L/h in a 5 L bioreactor, which is the highest production index reported. This study provides rational guidance for increasing the productivity of other chemicals.
研究领域:
生物工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Sai Fang,Zhe Wang,Lanxin Xiao,Yan Meng,Yixuan Lei,Tianxin Liang,Yuhuan Chen,Xiaoshu Zhou,Gang Xu,Lirong Yang,Wenlong Zheng,Jianping Wu
l -threonine aldolase (LTA) catalyzes the synthesis of β -hydroxy- α -amino acids, which are important chiral intermediates widely used in the fields of pharmaceuticals and pesticides. However, the limited thermostability of LTA hinders its industrial application. Furthermore, the trade-off between thermostability and activity presents a challenge in the thermostability engineering of this enzyme. This study proposes a strategy to regulate the rigidity of LTA's V-shaped subunit by modifying its opening and hinge regions, distant from the active center, aiming to mitigate the trade-off. With LTA from Bacillus nealsonii as targeted enzyme, a total of 25 residues in these two regions were investigated by directed evolution. Finally, mutant G85A/M207L/A12C was obtained, showing significantly enhanced thermostability with a 20 °C increase in T 50 60 to 66 °C, and specific activity elevated by 34 % at the optimum temperature. Molecular dynamics simulations showed that the newly formed hydrophobicity and hydrogen bonds improved the thermostability and boosted proton transfer efficiency. This work enhances the thermostability of LTA while preventing the loss of activity. It opens new avenues for the thermostability engineering of other industrially relevant enzymes with active center located at the interface of subunits or domains.
研究领域:
生物化学
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酶工程
·
蛋白质工程
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DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2025
·Vol. 13
·期 36
·29994-30005
·
IF 9.5
Kuhang Liu,Rui Huo,Dongming Xu,Chengjun Liu,Lishun Bai,Yue Liu,Ying He,Feiyan Yu,Keli Bu,Zhi Chang
Aqueous zinc metal batteries (AZMBs) are promising for large-scale energy storage but suffer from Zn metal instability, dendritic growth, and parasitic reactions in conventional electrolytes, hindering commercialization. Here, we propose a synergistic strategy combining solvation engineering and surface adsorption using multifunctional L-threonine (L-Thr). We demonstrate that L-Thr regulates Zn2+ solvation by displacing H2O molecules to suppress water reactivity, disrupts the hydrogen-bond network of water clusters to reduce free water, and preferentially adsorbs on Zn(101) facets, forming a hydrophobic interface that homogenizes Zn2+ flux. These synergistic effects enable dendrite-free Zn deposition with minimal side reactions. Consequently, Zn//Cu half-cells achieve a Coulombic efficiency (CE) of 99.71% over 2000 cycles (2 mA cm−2, 1 mAh cm−2), while Zn//Zn symmetric cells exhibit exceptional stability for over 2500 hours (0.5 mA cm−2, 0.5 mAh cm−2). Remarkably, a Zn anode with 68.3% utilization operates stably for 240 hours. Moreover, a practical Zn//NH4V4O10 (Zn//NVO) pouch cell with lean anode capacity (N/P ratio = 2.94 : 1) and high cathode loading (12.03 mg cm−2) retains 85.4% capacity after 200 cycles, demonstrating its real-world applicability.
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DOI
高影响因子
BIOORGANIC & MEDICINAL CHEMISTRY
·
2022
·
IF 3.461
Baoqin Cai,Marco Bocola,Ameng Zhou,Fenshuai Sun,Qing Xu,Jiadong Yang,Tianran Shen,Zhaoqi Zhang,Lei Sun,Yaoyao Ji,Yong Koy Bong,Thomas Daussmann,Haibin Chen
l -Threonine aldolases (LTAs) employing pyridoxal phosphate (PLP) as cofactor can convert low-cost achiral substrates glycine and aldehyde directly into valuable β-hydroxy-α-amino acids such as (2 R ,3 S )-2-amino-3-hydroxy-3-(4-nitrophenyl) propanoic acid (( R,S )-AHNPA), which is utilized broadly as crucial chiral intermediates for bioactive compounds. However, LTAs’ stereospecificity towards the β carbon is rather moderate and their activity and stability at high substrate load is low, which limits their industrial application. Here, computer-aided directed evolution was applied to improve overall activity, selectivity and stability under desired process conditions of a l -threonine aldolase in the asymmetric synthesis of ( R,S )-AHNPA. Selectivity and stability determining regions were computationally identified for structure-guided directed evolution of LTA-variants under efficient biocatalytic process conditions using 40% ethanol as cosolvent. We applied molecular modeling to rationalize selectivity improvement and design focused libraries targeting the substrate binding pocket, and we also used MD simulations in nonaqueous process environment as an effective and promising method to predict potential unstable loop regions near the tetramer interface which are hot-spots for cosolvent resistance. An excellent LTA variant EM-ALDO031 with 18 mutations was obtained, which showed ∼ 30-fold stability improvement in 40% ethanol and diastereoselectivity ( de ) raised from 31.5% to 85% through a three-phase evolution campaign. Our fast and efficient data-driven methodology utilizing a combination of experimental and computational tools enabled us to evolve an aldolase variant to achieve the target of 90% conversion at up to 150 g/L substrate load in 40% ethanol, enabling the biocatalytic production of β-hydroxy-α-amino acids from cheap achiral precursors at multi-ton scale.
研究领域:
生物化学
·
酶工程
·
计算生物学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Li-Chao Wang,Lian Xu,Bing-Mei Su,Xin-Qi Xu,Juan Lin
L- threo -4-methylsulfonylphenylserine ethyl ester [(2 S , 3 R )- 1d ], a key building block of florfenicol which synthesized by esterification using ethanol and L- threo -4-methylsulfonylphenylserine [(2 S , 3 R )- 1b ] as substrates. L-threonine aldolase (LTA) is a promising biocatalyst for producing (2 S , 3 R )- 1b through a one-step process taking 4-Methylsulphonyl benzaldehyde ( 1a ) and glycine as substrates under the mild condition. However, the moderate C β -stereoselective blocked the industrial application of LTA. To address this issue, rational design by combination with prereaction state molecular dynamics (MD) simulation and per-residue energy decomposition algorithm are employed to engineer LTA for enhancing C β -stereoselective. As a result, a triple mutant N16A/E98S/Y314R (Mu3) is screened out to produce (2 S , 3 R )- 1b with 93.7% de and 90.2% conversion under the 300 mM 1a substrate loading. Furthermore, esterification is applied to synthesize (2 S , 3 R )- 1d with over 99% chiral purity and 99% product purity. The success of this study provides new insights for the rational design of LTA with improved C β -stereoselectivity and proves a chemo-enzymatic route for green synthesis of (2 S , 3 R )- 1d .
研究领域:
生物催化
·
酶工程
·
绿色化学
·
药物合成
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2015
·
IF 2.037
Xiaofen Ren,Chunying Zhu,Youguang Ma
Densities and viscosities of glycine, l-alanine, l-valine, l-threonine, and l-arginine in aqueous solutions of (0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) mol·kg–1 mannitol have been measured in the temperature range of (293.15 to 323.15) K under atmospheric pressure; then the measured densities and viscosities of experimental systems were correlated. These data were further used to calculate the apparent molar volumes (Vφ), the limiting partial molar volumes (Vφ0), the limiting partial molar volumes of transfer (ΔtrVφ0), the viscosity B-coefficients, and the free energies of activation per mole of solvent (Δμ10≠) and solute (Δμ20≠). The results were interpreted through solute–solute interaction and solute–solvent interaction on the basis of the cosphere overlap model and transition state theory.
研究领域:
生物化学
·
物理化学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2020
·
IF 7.539
Lian Xu,Li-Chao Wang,Bing-Mei Su,Xin-Qi Xu,Juan Lin
L-threonine transaldolase (PsLTTA) could asymmetric synthesize β-hydroxy-α-amino acids (HAAs) with excellent stereoselectivity, while the poor yield limited its further application. Here we provided a combinatorial strategy to improve HAAs production, by directed evolution of PsLTTA towards enhanced activity and introducing an acetaldehyde elimination system to avoid acetaldehyde over-accumulation. A novel high throughput screening (HTS) method for evaluating PsLTTA activity was developed and applied for directed evolution of PsLTTA. Subsequently, we co-expressed alcohol dehydrogenase and formate dehydrogenase to construct an acetaldehyde elimination system to remove acetaldehyde inhibition. Moreover, the above positive strategies were integrated. As a result, the (2S,3R)- p -methylsulfonyl phenylserine yield reached 154.0 mM and with 94.6% de value, the highest productivity and stereoselectivity of (2S,3R)-HAAs reported by enzymatic synthesis so far. Taken together, our studies provided an efficient and green route for chiral synthesis of (2S,3R)-HAAs, which might contribute to the industrialization production of these useful building blocks.
研究领域:
生物化学
·
生物技术
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
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