The Molecular Mechanism of Fluorescence Lifetime of Fluorescent Probes in Cell Membranes.

Fluorescence probes play crucial roles in unraveling the structure and dynamics of cell membranes including membrane fluidity, polarity, and lipid molecule ordering. The fluorescence lifetime of probes describes the average duration of time that a fluorescent molecule remains in an excited state before returning to the ground state, which is sensitive to environmental changes. However, the molecular mechanism and inherent properties to determine the fluorescence lifetimes remain unexplored and inadequately studied.

The Conformational Transitions and Dynamics of Lipase Regulated by Water-Oil Interfaces.

Structural dynamics and conformational transitions are crucial for the activities of enzymes. As one of the most widely used industrial biocatalysts, lipase could be activated by the water-oil interfaces. The interface activations were believed to be dominated by the close-to-open transitions of the lid subdomains.

Quantitative and direct serum albumin detection by label-free SERS using tunable hydroxyapatite nanostructure for prostate cancer detection.

With the aid of good biocompatibility and stability with hydroxyapatite (HAp) in protein separation and adsorption fields, we developed a novel extraction-isolation albumin analysis method by relying on the specific adsorption capacity of HAp, combining with surface-enhanced Raman spectroscopy (SERS) for prostate cancer screening. Two different nanostructures of HAp particles, including the HAp flower and HAp sphere, were synthesized with a hydrothermal method, and the targeted binding and extraction abilities of serum albumin of these two HAp particles were compared. By changing the morphology of the nanostructure, the albumin-adsorption capacity of HAp varied significantly.

Enzymatic synthesis of 2-phenethyl acetate in water catalyzed by an immobilized acyltransferase from .

Although water is an ideal green solvent for organic synthesis, it is difficult for most biocatalysts to carry out transesterification reactions in water because of the reversible hydrolysis reaction. 3D structural characteristics and the microenvironment of an enzyme has an important effect on its selectivity for the transesterification reaction over the hydrolysis reaction. A novel 2-phenethyl acetate synthesis technology was developed using acyltransferase (EC 3.

Phosphorylation Regulation on the Homo-Dimeric Binding of Transactive Response DNA-Binding Protein.

The dimerization of transactive response DNA-binding protein of 43 kDa (TDP-43) is crucial for the RNA metabolism, and the higher-order aggregation of TDP-43 would induce several neurodegenerative diseases. The dimerization and aggregation of TDP-43 are regulated by the phosphorylation on its N-terminal domain (NTD). Understanding the regulation mechanism of TDP-43 NTD dimerization is crucial for the preventing of harmful aggregation and the associated diseases.

Screening of perhydrolases to optimize glucose oxidase-perhydrolase-in situ chemical oxidation cascade reaction system and its application in melanin decolorization.

A novel glucose oxidase (GOD)-perhydrolase-in situ chemical oxidation (ISCO) cascade reaction system was designed, optimized, and verified the operation feasibility in this research. Among the determined four perhydrolases, acyltransferase from Mycobacterium smegmatis (MsAcT) displayed the highest specific activity for perhydrolysis reaction (76.4 U/mg) and the lowest K value to hydrogen peroxide (13.

Conceptual design of a high-speed electromagnetic switch for a modified flux-coupling-type SFCL and its application in renewable energy system.

The modified flux-coupling-type superconducting fault current (SFCL) is a high-efficient electrical auxiliary device, whose basic function is to suppress the short-circuit current by controlling the magnetic path through a high-speed switch. In this paper, the high-speed switch is based on electromagnetic repulsion mechanism, and its conceptual design is carried out to promote the application of the modified SFCL. Regarding that the switch which is consisting of a mobile copper disc, two fixed opening and closing coils, the computational method for the electromagnetic force is discussed, and also the dynamic mathematical model including circuit equation, magnetic field equation as well as mechanical motion equation is theoretically deduced.

Cell-bound lipases from Burkholderia sp. ZYB002: gene sequence analysis, expression, enzymatic characterization, and 3D structural model.

Background: The whole-cell lipase from Burkholderia cepacia has been used as a biocatalyst in organic synthesis. However, there is no report in the literature on the component or the gene sequence of the cell-bound lipase from this species. Qualitative analysis of the cell-bound lipase would help to illuminate the regulation mechanism of gene expression and further improve the yield of the cell-bound lipase by gene engineering.

[Screening for mutants with thermostabe lipase A from Burkholderia sp. ZYB002].

Objective: We improved the thermostability of LipA from Burkholderia cecapia ZYB002 by protein engineering technology to expand the application of lipase LipA.

Method: On the basis of B-factor value of lipase LipA, series of potential mutation hotspots were selected for iterative saturation mutagenesis and the corresponding small mutation gene libraries were then constructed to screen the hyperthermal variants.

Results: From the above mutation libraries, we obtained a series of mutants whose enzyme half-life at 55 degrees C increased by 1.

[Cloning, expression and characterization of a lipase gene, lipC24, from Burkholderia sp. ZYB002].

Objective: We cloned a lipase gene, lipC24, from Burkholderia sp. ZYB002 and characterized the recombinant lipase LipC24.

Method: Based on the known genomic DNA sequence from Burkholderia cecapia JK321, we designed a pair of specific primers for the lipC24 gene and then obtained the full length of lipC24 gene.

Construction of Aspergillus niger lipase mutants with oil-water interface independence.

Based on previous bioinformational analytical results [Shu ZY, et al. Biotechnol Prog 2009;25:409-16], four A. niger lipase (ANL) mutants, ANL-Ser84Gly, ANL-Asp99Pro, ANL-Lys108Glu and ANL-EαH (obtained by replacing the lid domain of ANL with the corresponding domain from A.

Production and characteristics of the whole-cell lipase from organic solvent tolerant Burkholderia sp. ZYB002.

The thermostable and organic solvent tolerant whole-cell lipase (WCL) was produced by Burkholderia sp. ZYB002 with broad spectrum organic solvent tolerance. The production medium of the WCL was primarily optimized, which resulted in the maximum activity of 22.

[Construction of Aspergillus niger lipase mutants with oil-water interface independence].

Based on previous bioinformational analysis results, two Aspergillus niger lipase (ANL) mutants, ANL-Ser84Gly and ANL-Asp99Pro were constructed to screen ANL mutants with oil-water interface independence. ANL-Ser84Gly still displayed a pronounced interfacial activation, while ANL-Asp99Pro displayed no interfacial activation. The specific activity of ANL-Ser84Gly towards p-nitrophenyl palmitate (-myristate, -laurate and -decanoate) decreased by 29.

A rapid and efficient method for directed screening of lipase-producing Burkholderia cepacia complex strains with organic solvent tolerance from rhizosphere.

Lipase from Burkholderia cepacia strain is one of the most versatile biocatalysts and is used widely in many biotechnological application fields including detergent additives, the resolution of racemic compounds, etc. Based on the known whole genomic information of B. cepacia strain, both ampicillin and kanamycin were added to the TB-T medium to screen B.

Aspergillus niger lipase: Heterologous expression in Pichia pastoris, molecular modeling prediction and the importance of the hinge domains at both sides of the lid domain to interfacial activation.

Aspergillus niger lipase (ANL) is an important biocatalyst in the food processing industry. However, there is no report of its detailed three-dimensional structure because of difficulties in crystallization. In this article, based on experimental data and bioinformational analysis results, the structural features of ANL were simulated.

Expressed sequence tag analysis of marine fungus Schizochytrium producing docosahexaenoic acid.

To investigate docosahexaenoic acid (DHA, C22:6n-3) biosynthesis pathway in marine fungus Schizochytrium sp. FJU-512, a cDNA library of the fungus was constructed and analyzed. The titers of primary library were up to 5.

[Cloning and expression of two elongase genes involved in the biosynthesis of docosahexaenoic acid in Thraustochytrium sp. FJN-10].

Docosahexaenoic acid (DHA C22:6n-3), a typical long chain polyunsaturated fatty acids (PUFAs) has many positive effects on diseases such as artherosclerosis, hypertriglyceridemia, hypertension and cancers. Marine fungi, especially Thraustochytrium spp. producing much DHA can serve as model organisms for explaining the mechanism on the biosynthesis of PUFA.

Aspergillus niger lipase: gene cloning, over-expression in Escherichia coli and in vitro refolding.

From the N-terminal amino acid sequence of the lipase from Aspergillus niger F044, a potential homologous gene A84689 to the lipanl (the gene encoding the lipase from Aspergillus niger F044) was identified. A pair of primers were designed according to the nucleotide sequence of A84689, and the lipanl was cloned by PCR. Nucleotide sequencing revealed that the lipanl has an ORF of 1,044 bp, containing three introns.

[Purification and characterization of a lipase from Aspergillus niger F044].

A lipase from Aspergillus niger F044 was purified to homogeneity using ammonium sulfate precipitation, dialysis, DEAE-Sepharose Fast Flow anion exchange chromatography and Sephadex G-75 gel filtration chromatography. This purification protocol resulted in a 73.71-fold purification of lipase with 33.