Frontiers of Chemical Science and Engineering
·
2020
·Vol. 14
·期 5
·868-879
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IF 3.552
Shen Jiang-Wei,Cai Xue,Dou Bao-Juan,Qi Feng-Yu,Zhang Xiao-Jian,Liu Zhi-Qiang,Zheng Yu-Guo
A lipase from Sporisorium reilianum SRZ2 (SRL) with 73% amino acid sequence identity to Candida antarctica lipase B (CALB) was cloned and overexpressed in Pichia pastoris . The recombinant SRL showed a preference for short-chain p -nitrophenyl esters. It achieved maximum activity at pH 8.0 and 65°C for p -nitrophenyl hexanoate (C6) with K m and k cat / K m values of 0.14 mmol·L −1 and 1712 min −1 · mmol · L −1 at 30°C, respectively. SRL displayed excellent thermostability and pH stability, retaining more than 79% of its initial activity after incubation at 60°C for 72 h and 75% at pH 3 to 11 for 72 h. It also maintained most of its activity in the presence of inhibitors and detergents except sodium dodecyl sulfate, and it tolerated organic solvents. SRL was covalently immobilized and successfully used for ethyl hexanoate synthesis in cyclohexane or in a solvent-free system with a high conversion yield (> 95%). Furthermore, high conversion yield was also achieved for the synthesis of various short-chain flavor esters when high substrate concentrations of 2 mol · L −1 were applied. This study indicated that a CALB-type lipase from S. reilianum SRZ2 showed great potential in organic ester synthesis.
研究领域:
生物化学
·
酶工程
·
食品科学
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DOI
高影响因子
Engineering
·
2022
·
IF 12.834
Xue Cai,Jiang-Wei Shen,Yu Qiang,Jing Hua,Zhang-Qi Ma,Zhi-Qiang Liu,Yu-Guo Zheng
Lipase-catalyzed stereoselective resolution of cis -(±)-dimethyl 1-acetylpiperidine-2,3-dicarboxylate ( cis -(±)-1) is an attractive route for the synthesis of ( S,S )-2,8-diazobicyclo[4.3.0]nonane, an important chiral intermediate of the fluoroquinolone antibiotic, moxifloxacin. In our previous study, a lipase from Sporisorium reilianum (SRL) was identified to possess excellent thermostability and pH stability. However, the low enzymatic activity of the SRL is a challenge that must be addressed. A rational design was initially employed for SRL tailoring according to the engineered Candida antarctica lipase B (CALB), resulting in a beneficial variant called SRL-I194N/V195L. Subsequently, two key amino acid residues in loop 6, L145 and L154, which might modulate the lid conformation between open and closed, were identified. A tetra-site variant, SRL-I194N/V195L/L145V/L154G (V13), with a significantly enhanced activity of 87.8 U∙mg −1 was obtained; this value was 2195-fold higher than that of wild-type SRL. Variant V13 was used to prepare optically pure (2 S ,3 R )-dimethyl 1-acetylpiperidine-2,3-dicarboxylate ((2 S ,3 R )-1), resolving 1 mol∙L −1 cis -(±)-1 with a conversion of 49.9% in 2 h and absolute stereoselectivity ( E > 200). Excellent stability with a half-life of 92.5 h was also observed at 50 °C. Overall, the study findings reveal a lipase with high activity toward cis -(±)-1 at an industrial level and may offer a general strategy for enhancing the enzyme activity of other lipases and other classes of enzymes with a lid moiety.
研究领域:
生物化学
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生物技术
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酶学
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药物化学
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有机化学
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DOI
高影响因子
CHEMISTRY & BIODIVERSITY
·
2026
·Vol. 23
·期 7
·e71476
·
IF 2.9
Changchang Gao,Zefeng Xia,Chengwei Xu,LeiFang Zhang,Chengjie Tong,Chunyu Niu,Boyi Fan,Yan Chen,Yin Chen
Sporisorium reilianum ( S. reilianum ) is an agricultural pathogen that causes disease and reduces yield in sorghum and maize crops. However, head smut-infected sorghum and maize have been traditionally utilized for edible and medicinal purposes in some regions. In this study, the structure and immunostimulatory potency of a new slightly branched β-glucan WM-0.25(P) obtained from the S. reilianum -infected sorghum head smut were explored. WM-0.25(P) was a β-glucan with a molecular weight of 69.67 kDa and was composed of β-1,6-D-Glcp as the main chain and β-1,3-D-Glcp as the side chain. There was approximately one branch for every 11 sugars on the main chain. WM-0.25(P) triggered morphological alterations, enhanced phagocytic activity, and upregulated the expression of surface molecules, while promoting the production of ROS, NO, and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β) in RAW264.7 macrophages. The function blocking antibodies to toll-like receptor revealed that TLR4 mainly participated in the recognition and immunostimulatory function of WM-0.25(P). Simultaneously, WM-0.25(P) modulated macrophage inflammatory response mainly through activation of the TLR4/MyD88/NF-κB signaling pathway. The results indicated that WM-0.25(P), with a low branching degree derived from S. reilianum -infected sorghum head smut, exerted moderate immunomodulatory effects on macrophages. Further in vivo studies are warranted to evaluate its translational potential. Graphical This β-glucan (69.67 kDa) from S. reilianum -infected sorghum has a β-1,6 backbone with β-1,3 branches. It moderately activates RAW264.7 macrophages via TLR4/MyD88/NF-κB, promoting cytokine/ROS/NO production and phagocytosis.
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PubMed
高影响因子
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