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101.
Cheon-Soon Bae Sung-Sang Hong Sang-Jeom Ahn Yang-Suk Jang Byung-Ki Hur 《Biotechnology and Bioprocess Engineering》2005,10(3):230-235
For the acellular pertussis vaccine with a high immunogenicity, the concentration, composition and characteristics of acellular
pertussis antigens are the crucial points to be considered. Nevertheless, it has not been proved yet whether or not the polymerization
degree, one of the characteristics of formalin-detoxified acellular pertussis antigens, has an influence on vaccine potency.
Thus, in the present study, the correlations among detoxification conditions of acellular pertussis bulks, their polymerization
degrees and their immunogenicities were examined. In addition, the relative importance of pertussis toxoid in vaccine immunogenicity
was also investigated. Results show that a lower lysine concentration during detoxification induces highly-polymerized antigens,
the immunogenicity has a great dependency on the polymerization degree of antigens, and also pertussis toxoid has a relatively
stronger influence on the immunogenicity than other antigens. Accordingly, in the aspect of the potency of detoxified acellular
pertussis vaccine, it can be demonstrated that the polymerization of antigens and its degree are the major factors affecting
the immunogenicity along with a relatively high content of pertussis toxoid. 相似文献
102.
Amino acid-sugar alcohol conjugates were synthesized by a commercial serine protease, Optimase M-440, in organic media. Optimase M-440 showed broad substrate specificity towards N-t-Boc-protected l-amino acids as acyl donors and sugar alcohols as nucleophiles. Among various solvents tested Optimase M-440 showed the highest activity in pyridine. The regioselective acylation of the primary –OH groups of sugar alcohols gave the amino acid conjugates in good yields without byproducts. 相似文献
103.
Byung-Ki Hur Dae-Won Cho Ho-Jung Kim Chun-Ik Park Hyung-Joon Suh 《Biotechnology and Bioprocess Engineering》2002,7(1):10-15
Environmental and medium factors were investigated as basic data for optimizing DHA production when usingThraustochytrium aureum. To study the effect of environmental conditions, the rotation speed and culture temperature were, changed. Plus the trend
of the growth characteristics, lipid content in the biomass, and DHA content in lipids were evaluated according to various
initial glucose concentrations. The biomass, lipid, and DHA analyses showed that the physiological characteristics ofT. aureum were closely related with the environmental and medium conditions, as in the case of other marine microorganisms. For example,
a low rotation speed of 50 rpm lowered the cell growth rate as well as the DHA content in the lipids. A low temperature had
a negative effect on the cell growth, yet a positive effect on the lipid content in the biomass. Different initial glucose
concentrations had no effect on the lipid content in the biomass or DHA content in the lipids, yet did affect the cell growth.
Accordingly, these results show that environmental and medium factors must be synthetically considered in order to optimize
DHA production when usingT. aureum. 相似文献
104.
Xuejun Cao XingYan Wu Tong Wu Keming Jin Byung Ki Hur 《Biotechnology and Bioprocess Engineering》2001,6(3):200-204
In this study, nanofiltration was applied to the concentration of the 6-aminopenicillinic acid (6-APA) from bioconverted penicillin
solution and also to its mother liquor. The 6-APA in the solution was concentrated from 0.211 mol/L to 0.746 mol/L by nanofiltration.
The final maximum concentration was 3.6 times higher than the initial concentration and the recovery yield was 97% to 99%
of the original 6-APA. The concentrated solution was crystallized with the yields of 88.9–90.2% and the purity of the crystallized
product was about 98%. The concentration of 6-APA in the mother liquor after crystallization was 0.014 mol/L and thus was
concentrated 20–30 fold by nanofiltration and crystallization. The recovery of 6-APA was over 98%. The salts contained in
the mother liquor, such as NH4Cl and KCl, could be removed by allowing them to permeate through the membrane. 相似文献
105.
106.
Hyun-Jin Kang Tuong Vy Thi Le Kyungmin Kim Jeonghwan Hur Kyeong Kyu Kim Hyun-Ju Park 《Journal of molecular biology》2014
Both G-quadruplex and Z-DNA can be formed in G-rich and repetitive sequences on genome, and their formation and biological functions are controlled by specific proteins. Z-DNA binding proteins, such as human ADAR1, have a highly conserved Z-DNA binding domain having selective affinity to Z-DNA. Here, our study identifies the Z-DNA binding domain of human ADAR1 (hZαADAR1) as a novel G-quadruplex binding protein that recognizes c-myc promoter G-quadruplex formed in NHEIII1 region and represses the gene expression. An electrophoretic migration shift assay shows the binding of hZαADAR1 to the intramolecular c-myc promoter G-quadruplex-forming DNA oligomer. To corroborate the binding of hZαADAR1 to the G-quadruplex, we conducted CD and NMR chemical shift perturbation analyses. CD results indicate that hZαADAR1 stabilizes the parallel-stranded conformation of the c-myc G-quadruplex. The NMR chemical shift perturbation data reveal that the G-quadruplex binding region in hZαADAR1 was almost identical with the Z-DNA binding region. Finally, promoter assay and Western blot analysis show that hZαADAR1 suppresses the c-myc expression promoted by NHEIII1 region containing the G-quadruplex-forming sequence. This finding suggests a novel function of Z-DNA binding protein as a regulator of G-quadruplex-mediated gene expression. 相似文献
107.
Hyuck Choi Byung-Chul Jeong Sung-Woong Hur Jung-Woo Kim Keun-Bae Lee Jeong-Tae Koh 《PloS one》2015,10(10)
Craniofacial bone defects are observed in a variety of clinical situations, and their reconstructions require coordinated coupling between angiogenesis and osteogenesis. In this study, we explored the effects of cartilage oligomeric matrix protein-angiopoietin 1 (COMP-Ang1), a synthetic and soluble variant of angiopoietin 1, on bone morphogenetic protein 2 (BMP2)-induced cranial bone regeneration, and recruitment and osteogenic differentiation of perivascular pericytes. A critical-size calvarial defect was created in the C57BL/6 mouse and COMP-Ang1 and/or BMP2 proteins were delivered into the defects with absorbable collagen sponges. After 3 weeks, bone regeneration was evaluated using micro-computed tomography and histologic examination. Pericyte recruitment into the defects was examined using immunofluorescence staining with anti-NG2 and anti-CD31 antibodies. In vitro recruitment and osteoblastic differentiation of pericyte cells were assessed with Boyden chamber assay, staining of calcified nodules, RT-PCR and Western blot analyses. Combined administration of COMP-Ang1 and BMP2 synergistically enhanced bone repair along with the increased population of CD31 (an endothelial cell marker) and NG2 (a specific marker of pericyte) positive cells. In vitro cultures of pericytes consistently showed that pericyte infiltration into the membrane pore of Boyden chamber was more enhanced by the combination treatment. In addition, the combination further increased the osteoblast-specific gene expression, including bone sialoprotein (BSP), osteocalcin (OCN) and osterix (OSX), phosphorylation of Smad/1/5/8, and mineralized nodule formation. COMP-Ang1 can enhance BMP2-induced cranial bone regeneration with increased pericyte recruitment. Combined delivery of the proteins might be a therapeutic strategy to repair cranial bone damage. 相似文献
108.
Kazuki Kato Sadeem Ahmad Zixiang Zhu Janet M. Young Xin Mu Sehoon Park Harmit S. Malik Sun Hur 《Molecular cell》2021,81(3):599-613.e8
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109.
110.
Cultures of water fern Azolla pinnata R. Br. exposed for 1 weekto either 30, 50 or 80 nl l-1 O3 showed significant reductionsin rates of growth and N2 fixation, and had fewer heterocysts.Although the levels of glutamine synthetase (GS) and glutamatedehydrogenase (GDH) activity were decreased by low concentrationsof O3 exposures (30 or 50 nl l-1), significant increases inlevels of the same enzymes were caused by higher concentrationsof O3 (80 nl l-1). Increased levels of total protein, polyamines(putrescine and spermidine), and the xanthophyll-cycle precursorof abscisic acid (ABA), violaxanthin, were also found with higherlevels of O3 (80 nl l-1). Levels of ABA itself were significantlyincreased by low level O3 fumigation (30 nl l-1) but significantlydecreased by exposure to 80 nl l-1 O3. This may indicate thathigher levels of atmospheric O3 inhibit the final stages ofABA biosynthesis from violaxanthin.Copyright 1994, 1999 AcademicPress Abscisic acid, nitrogen assimilation, nitrogen fixation, ozone pollution, polyamines, violaxanthin 相似文献