Our work here, for the first time, reported the use of chitosan-mediated biomimetic silica nanoparticles in enzyme immobilization. In order to make clear the relationship among silicification process, silica nanoparticle structure and immobilized enzyme activity, a mechanism of chitosan-mediated silicification using sodium silicate as the silica source was primarily evaluated. Chitosan was demonstrated effectively to promote the silicification not only in accelerating the aggregation rate of sodium silicate, but also in templating the formation of silica nanoparticles.
View Article and Find Full Text PDFNovel hybrid magnetic cross-linked enzyme aggregates of phenylalanine ammonia lyase (HM-PAL-CLEAs) were developed by co-aggregation of enzyme aggregates with magnetite nanoparticles and subsequent crosslinking with glutaraldehyde. The HM-PAL-CLEAs can be easily separated from the reaction mixture by using an external magnetic field. Analysis by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) indicated that PAL-CLEAs were inlayed in nanoparticle aggregates.
View Article and Find Full Text PDFBioresour Technol
January 2012
A unique method that applied a multilayer-immobilization strategy was developed to prepare nanofibrous enzymes for biosynthesis. LiCl co-electrospun with polyurethane nanofibers enabled strong physical adsorption of bovine serum albumin (BSA), forming the first layer of protein on the nanofibers; lipase AK was subsequently crosslinked to BSA as an outer layer of enzyme. The content of LiCl in nanofibers was found to be a sensitive factor affecting the activity and stability of the immobilized lipase.
View Article and Find Full Text PDFBiotechnol Lett
September 2011
TiO(2) nanofibers with uniform diameter about 125 nm were prepared based on sol-gel process and electrospinning technology. Protex 6L, an industrial alkaline protease, was covalently immobilized on TiO(2) nanofiber through γ-aminopropyltriethoxysilane modification and glutaraldehyde crosslinking. With 2 (v/v)% glutaraldehyde as crosslinker, the enzyme loading is about 201 mg (g nanofiber membrane)(-1), and the specific activity of the immobilized Protex 6L is 2.
View Article and Find Full Text PDFZhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi
June 2010
Objective: To study the changes of T-Lymphocyte and activated T-Lymphocyte subsets in influenza A (H1N1) virus patients.
Methods: The percentages of the subsets of Lymphocyte were detected by flow cytometry in influenza A (H1N1) virus patients (n = 144) and normal controls (n = 41). Furthermore, the subsets of T-Lymphocyte and activated T-lymphocyte were analyzed in 83 among those patients before and after treatment.
LiCl is a kosmotrope that generally promotes protein salvation in aqueous solutions. Herein we report that LiCl embedded in electrospun polymeric nanofibers interestingly induced an abnormal protein adsorption and substantially augmented the adsorption capacity of the fibers. As a result, equilibrium protein loadings reached over 64% (w/w) of the dry mass of fibers, 9-fold higher than that observed in the absence of the salt.
View Article and Find Full Text PDFCofactor-dependent biotransformations often require consumption of a secondary substrate for cofactor regeneration. Alternatively, two synthetic reactions may be coupled together through cofactor regeneration cycles. Simultaneous production of value-added products from glycerol and xylose was realized in this work through an enzymatic NAD(H) regeneration cycle involving two enzymes.
View Article and Find Full Text PDFZhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi
February 2010
Objective: To investigate the expression of CD95 and special marker for activation of peripheral blood lymphocytes in patients with hand foot and mouth disease (HFMD) and its significance.
Methods: Immunofluorescent two-color flow cytometry was used to study the expression of CD95 and HLA-DR on lymphocytes in 58 patients with HFMD and 34 normal controls.
Results: Expression of CD3+ T cells was significantly lower in patients (63.