查找使用阿拉丁产品的科研文献

Molecular determinants for the association of human hormone-sensitive lipase with lipid droplets

Peng Han,Xu Qikui,Zhang Ting,Zhu Jiakai,Pan Jinheng,Guan Xiaoyu,Feng Shan,Wu Jianping,Hu Qi

Lipid droplets (LDs) are the main cellular storage sites for triacylglycerols (TAGs), playing an important role in energy homeostasis and cell signaling. Hydrolysis of the stored TAGs begins with conversion of TAGs into diacylglycerols (DAGs) by adipose triglyceride lipase (ATGL), followed by hydrolysis of DAGs by hormone-sensitive lipase (HSL). Despite the central role of HSL in lipolysis, the molecular determinants for its LD association have remained elusive. Here, we report the cryo-EM structure of human HSL at 3.4 Å. Combining this with hydrogen-deuterium exchange mass spectrometry, biochemical and cellular assays, we identify residues 489-538, referred to as the “H-motif”, and the N-terminal 4-helix bundle of HSL as LD-binding motifs mediating direct interaction of HSL with LDs. LD binding mediated by the LD-binding motifs is independent of HSL phosphorylation catalyzed by the cAMP-dependent kinase PKA. Our findings provide insight into the LD binding mechanism of HSL, advancing our understanding of the regulation of lipolysis.

Green synthesis of tetra-substituted 2H-pyrans catalyzed by lipase in aqueous medium

Shenhan Xie,Yanyang Sun,Xu Yan,Yu Han,Chunyu Wang,Fengxi Li,Lei Wang,Zhi Wang

An efficient and environmental method was employed to synthesize multi-substituted 2H-pyran from methyl coumalate and β-keto esters or diketones. Porcine pancreas lipase (PPL) can catalyze this transformation in high yields (74–96%) in aqueous medium (H2O: DMSO = 2:1) under mild conditions (60 °C). The reported strategy exhibits high functional group compatibility and broad substrate scope. In addition, it provides access to a variety of tetra-substituted 2H-pyrans which are considered privileged scaffolds with diverse biological activities.

Efficient Synthesis of Tetrasubstituted Furans via Lipase-Catalyzed One-Pot Sequential Multicomponent Reaction

Yongqi Zeng,Yong Tang,Minglu Xu,Dantong Wang,Zhi Wang,Yin Gao,Lei Wang

Tetrasubstituted furans and their derivatives represent a versatile class of important heterocyclic frameworks widely distributed in natural products. These scaffolds also demonstrate significant potential in pharmaceutical chemistry, materials science, and organic synthesis methodologies. In this study, we successfully established a synergistic catalytic system utilizing benzoylacetonitriles, aldehydes, and benzoyl chlorides as substrates, facilitated by tributylphosphine and immobilized lipase (Novozym 435), to achieve efficient synthesis of cyano-containing tetrasubstituted furans. Under optimized conditions, we obtained a series of target products exhibiting exceptional substrate tolerance with good to excellent isolated yields ranging from 80% to 94%. Additionally, we proposed a reasonable reaction mechanism and verified it through controlled experiments. This methodology not only expands the synthetic utility of lipase in non-natural transformations but also establishes a paradigm of green chemistry for the construction of tetrasubstituted furans.

pH-Tunable gliadin–chitosan–lipase ternary complexes enabling efficient interfacial synthesis of phytosterol ester

Huanyu Zheng,Ji Zhang,Zhouliang Sun,Mengqi Wang,Yufei Zhang,Mingming Zheng

Nature employs non-catalytic scaffold proteins to achieve precise enzyme positioning and enhanced catalysis. However, mimicking this approach with food-grade macromolecular materials remains a significant challenge. Herein, we introduce a pH-tunable gliadin-chitosan matrix designed to act as a bioinspired scaffold. It spontaneously self-assembles with lipase into stable ternary complex, gliadin-chitosan-lipase (GCL), through robust hydrogen bonding and hydrophobic interactions (∆G_binding = −331.7 kJ‧mol −1 ) immobilize lipase AYS in an optimally active conformation. Upon addition to an oil-water mixture at pH 7, GCL particles adsorb at the interface, creating a highly efficient Pickering interfacial biocatalysis (PIB) system. When applied to the synthesis of sterol esters via interesterification with flaxseed oil, the GCL-stabllized PIB system achieved an 81.4 % yield within 6 h, a relative conversion rate of almost three times that of free lipase (31.8 %), and maintained 73.4 % of its initial activity after five consecutive cycles. Its compatibility extended to six commercial oils. Molecular dynamics results indicated that lipase acts as a regulatory element, suppressing global fluctuations to generate stable structures with high catalytic activity, thereby preparing the interface for biocatalysis. This work establishes a sustainable, scalable platform for functional lipid production and provides a blueprint for next-generation biomacromolecular enzyme carriers.

Enhancing bio-catalytic activity and stability of lipase nanogel by functional ionic liquids modification

Bin Zou,Yan Yan,Jiaojiao Xia,Liming Zhang,Idowu Onyinye Adesanya

A novel integrated lipase nanogel based on functional ionic liquid modification and polymerization immobilization with improved stability was designed. Characterization before and after modification and polymerization was conducted using infrared spectroscopy, Circular dichroism spectroscopy, fluorescence spectroscopy, and scanning electron microscopy. It was shown that the modification of the ionic liquid influenced the catalytic behavior of lipase significantly due to the changed structure and surface properties of lipase. The enzymatic properties, including acid-base stability, thermal stability, organic solvents stability, and storage stability of CRL nanogel, were investigated in the p-nitrophenyl palmitate hydrolysis reaction (CRL, Lipase from Candida Rugosa ). The results indicated that CRL nanogel has a better pH, heat, and organic solvent tolerance after immobilization. After seven weeks of storage, the natural CRL gradually lost its enzymatic activity, and only 17.5±1.7 % of the catalytic activity remained, the residual activity of CRL nanogel was 97.3±1.8 %. It was indicated that the novel CRL nanogel was an excellent biocatalyst.

High Performance Medium- and Long-Chain Diester Electrical Insulating Oil Biosynthesized via Lipase Catalyzation

Liangxuan Ouyang,Feipeng Wang,Qiuhuang Han,Jian Li,Yang Xu,Yihua Qian,Massimo Pompili,Fabio Scatiggio,Campi Giorgio,Pawel Rozga,Yibo Ren

Green Synthesis of Spirooxindoles via Lipase-Catalyzed One-Pot Tandem Reaction in Aqueous Media

Yong Tang,Ciduo Wang,Hanqing Xie,Yuelin Xu,Chunyu Wang,Chuang Du,Zhi Wang,Lei Wang

The development of non-natural enzymatic catalysis is important for multicomponent tandem organic transformations. However, the delicate acting environments of biological enzymes still present some challenges in the synthesis of spirooxindole skeleton via enzymatic catalysis. To address these issues, a lipase-catalyzed method was developed for the synthesis of spirooxindole frameworks. Using easily available isatins, cycloketones, and malononitriles as substrates, mild reaction conditions, and a reasonable reaction time, moderate to good yields (67–92%) and excellent functional group tolerance were accomplished via this protocol. The related mechanism explanation is also speculated in this paper.Keywords:spirooxindoles;lipase catalysis;one-pot tandem process;green synthesis

Lipase-catalyzed synthesis of azido-functionalized aliphatic polyesters towards acid-degradable amphiphilic graft copolymers

Wan-Xia Wu,Na Wang,Bei-Yu Liu,Qing-Feng Deng,Xiao-Qi Yu

A series of novel aliphatic polyesters with azido functional groups were synthesized via the direct lipase-catalyzed polycondensation of dialkyl diester, diol and 2-azido-1,3-propanediol (azido glycerol) using immobilized lipase B from Candida antarctica (CALB). The effects of polymerization conditions including reaction time, temperature, enzyme amount, substrates and monomer feed ratio on the molecular weights of the products were studied. The polyesters with pendant azido groups were characterized by 1H NMR, 13C NMR, 2D NMR, FTIR, GPC and DSC. Alkyne end-functionalized poly(ethylene glycol) containing a cleavable acetal group was then grafted onto the polyester backbone by copper-catalyzed azide–alkyne cycloaddition (CuAAC, click chemistry). Using fluorescence spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM), these amphiphilic graft copolymers were found to readily self-assemble into nanosized micelles in aqueous solution with critical micelle concentrations between 0.70 and 1.97 mg L−1, and micelle sizes from 20–70 nm. The degradation of these polymers under acidic conditions was investigated by GPC and 1H NMR spectroscopy. Cell cytotoxicity tests indicated that the micelles had no apparent cytotoxicity to Bel-7402 cells, suggesting their potential as carriers for controlled drug delivery.

A reverse micelle strategy for fabricating magnetic lipase-immobilized nanoparticles with robust enzymatic activity

Yi Shixiong,Dai Fangyin,Zhao Cunyi,Si Yang

Enzyme-immobilized nanoparticles that are both catalysis effective and recyclable would have wide applications ranging from bioengineering and food industry to environmental fields; however, creating such materials has proven extremely challenging. Herein, we present a scalable methodology to create Candida rugosa lipase-immobilized magnetic nanoparticles (L-MNPs) by the combination of nonionic reverse micelle method and Fe 3 O 4 nanoparticles. Our approach causes the naturally abundant and sustainable Candida rugose lipase to ordered-assemble into nanoparticles with high catalytic activity and durability. The resultant L-MNPs exhibit the integrated properties of high porosity, large surface area, fractal dimension, robust enzymatic activity, good durability, and high magnetic saturation (59 emu g −1 ), which can effectively catalyze pentyl valerate esterification and be easily separated by an external magnet in 60 second. The fabrication of such fascinating L-MNPs may provide new insights for developing functional enzyme-immobilized materials towards various applications.

Encapsulation of Fe3O4 and Lipase in a Squarate Metal–Organic Framework for Nonaqueous Catalysis

Bo Xie,Chaonan Jin,Wei Jin,Hao Chen,Yahui Zhang,Zewei Wang,Hongde An

Enzyme immobilization in metal–organic frameworks (MOFs) has emerged as a promising strategy to enhance the stability and reusability of biocatalysts. However, maintaining high enzymatic activity, especially in nonaqueous media, remains a challenge. Herein, we report a facile one-pot in situ encapsulation strategy to coincorporate Fe3O4 nanoparticles and lipase within the cavities of NKMOF-101. The synthesized Fe3O4/lip@NKMOF-101-Ni composite was thoroughly characterized, which confirmed the successful encapsulation of both components. The incorporated Fe3O4 nanoparticles not only endowed the biocomposite with magnetic susceptibility for facile separation but also surprisingly acted as an activity enhancer. In the esterification reaction conducted in a nonaqueous system, the Fe3O4/lip@NKMOF-101-Ni composite demonstrated significantly enhanced catalytic activity, achieving an approximately 6-fold increase compared to free lipase. Furthermore, the magnetic biocomposite exhibited excellent operational stability, retaining over 80% of its original activity after five consecutive uses and could be efficiently recycled. This work presents a novel and effective approach for constructing robust and highly active enzyme-MOF composites for advanced applications in nonaqueous biocatalysis.

Inactivation Kinetic Analysis of Lipase and Lipoxygenase in Rice Bran Through Cold Plasma Treatment

Xueyuan Lin,Wencheng Yang,Yuting Wang,Yi Chen,Chang Li

As an emerging technology for the preservation and sterilization of agricultural products, cold plasma has demonstrated significant potential. This study aimed to investigate the effects of dielectric barrier discharge (DBD) cold plasma on the activities of lipase and lipoxygenase in rice bran and to establish a kinetic model for enzyme inactivation to characterize the action of plasma on these two enzymes. Rice bran samples were treated with DBD plasma at various voltages (35–55 kV) for different durations (0–20 min). The results indicated that both voltage and treatment time had significant effects on the inactivation of lipase and lipoxygenase, reducing them by 91.51% and 96.43%, respectively. Four kinetic models, log-linear, Weibull, Logistic, and Peleg, were applied to fit the experimental data, and corresponding model parameters were calculated. The analysis revealed that the Logistic model best described lipase inactivation, while the Weibull model was most suitable for lipoxygenase. Under identical treatment conditions, lipase exhibited relatively high stability, whereas lipoxygenase has a stronger adaptability under more severe conditions.

Lipase immobilized on novel ceramic supporter with Ni activation for efficient cinnamyl acetate synthesis

Zhongjie Wu,Wei Qi,Mengfan Wang,Rongxin Su,Zhimin He

The metal ceramic powder (MCP) was used for lipase immobilization. The MCP containing Ni 2+ (Ni-MCP) exhibited the best affinity to lipase . The effects of heating rate, lipase concentration and immobilization time on immobilized lipase (Ni-MCP-lipase) activity were measured. Under the optimal preparation conditions (heating rate: 1   °C/min, lipase concentration: 9   mg/mL, immobilization time: 8   h), Ni-MCP-lipase could obtain 1.4   U/g and 216% of activity yield. The Ni-MCP-lipase, with improved thermal stability and storage stability, had optimal pH value of 6.0 and optimal temperature of 40   °C. The characterizations clarified the effect of heating rate on Ni-MCP-lipase activity, and confirmed that lipase had been efficiently immobilized on Ni-MCP surface. Finally, cinnamyl acetate synthesis demonstrated that Ni-MCP-lipase had improved efficiency compared with free lipase. Under the optimal reaction conditions (Ni-MCP-lipase loading: 3   g; reaction temperature: 35   °C; acetic acid/cinnamyl alcohol: 2:1 in 15.0   mL reaction system), the cinnamyl acetate yield would reach 62.56%.