http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Guise, Andrew D.,Chaudhuri, Julian B. The Korean Society for Biotechnology and Bioengine 2001 Biotechnology and Bioprocess Engineering Vol.6 No.6
The effects of several variables on the refolding of hen egg white lysozyme have been studied, Lysozyme was denatured in both urea, and guanidine hydrochloride(GuHCl), and batch refolded by dilution (100 to 1000 fold) into 0.1 M Tris-HCI, pH 8.2 mM EDTA 3 mM reduced glutathione and 0.3 mM oxidised glutathions. Refolding was found to be sensitive to temperature, with the highest refolding yield obtained at 50$\^{C}$. The apparent activation energy for lysozyme re-folding wasf ound to be 56kJ/mol, Refolding by dilution results in low concentrations of both de-naturant and reducing agent species. It was found that the residual concentrations obtained dur-ing dilution(100-fold dilution:[GuHCI]=0.06 mM, [DTT]=0.15 mM) were significant and could inhibit lysozyme refolding. This study has also shown that the initial protein concentration (1-10mg/mL) that is refolded is an important parameter. In the presence of residual GuHCl and DTT higher refolding yields were obtained when starting from higher initial lysozyme concentra-tions. This trend was reversed when residual denaturant components were removed from the re-folding buffer.
GENE TRANSFER BY MANIPULATION OF PRIMORDIAL GERM CELLS IN THE CHICKEN
Han, Jac Y.,Shoffner, R.N.,Guise, K.S. Asian Australasian Association of Animal Productio 1994 Animal Bioscience Vol.7 No.3
The primordial germ cells (PGCs) were transfected in vitro and expressed the exogenous RSVLTR/${\beta}G2$ plasmid, suggesting thaI PGC is a possible vector for direct gene transfer into the germ line. Transfection efficiency of cell suspensions containing PGCs was 1.5% by liposome mediated DNA transfection. By microinjection of the transfected PGCs into the host germinal crescent, PGCs migrated via blood vessel to the future gonad and these transfected PGCs resulted in the RSVLTR/${\beta}G2$ expression in the gonad. The results from the seeding of PGCs on the chorioallantoic membrane were insufficient to test the hypothesis that PGCs can penetrate or invade the chorioallantoic membrane for transport via the circulatory system.
STABLE TRANSFORMATION OF CULTURED CHICKEN CELLS
Han, J.Y.,Shin, Y.S.,Shoffner, R.N.,Guise, K.S. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.4
A plasmid vector, $RSVLTR/{\beta}G2$, containing lacZ gene under the control of the RSVLTR promoter were transfected into chicken embryo fibroblasts by three different transfection methods. Calcium phosphate, lipsome and DEAE-dextran techniques were applied for transfection of chicken cells. A histochemical assay with X-gal was used as a simple method for screening transfected cells. Plasmid $RSVLTR/{\beta}G2$ was expressed proficiently in the chicken embryo fibroblast. Calcium phosphate-DNA precipitate transfection resulted in the highest efficiency for transient expression of $RSVLTR/{\beta}G2$. Transfected cells formed colonies on the 9th day of incubation indicating stable transformation of the inserted plasmid.
닭 초기 배아의 유전자 미세주입과 유전자 발현에 관한 연구
한재용(J . Y . Han),(R . N . Shoffner),(K . S . Guise) 한국축산학회 1994 한국축산학회지 Vol.36 No.3
This study was carried out to examine the expression of marker genes and integration of plasmid DNA into the germ cells in young chicken embryos. The RSVLTR/βG2 plasmid contains the lacZ gene under the control of rous sarcoma virus (RSV) long terminal repeat(LTR) promoter. After a square window of 5㎜ per side was cut in the side of the egg with a dentistry drill, the transfection cocktail of calcium-phosphate or lipofectin with plasmid DNA was microinjected in the area of blastoderm and germinal crescent whose developmental stages were stage X and stage 6 to 8, respectively. Microinjected eggs were sealed, and the eggs were returned to the incubator with the $quot;window$quot; side up overnight. Microinjected embryos with plasmid DNA were screened with Xgal, and the marker gene was expressed in the brain, notochord and other parts of body of 1.5∼4.5 day old embryos, suggesting that developing stem cells in unincubated blastoderms or 1∼4 somite embryos can be transfected with plasmid vectors. The possibility of germ line integration with plasmid DNA by direct microinjection into early chicken embryos was determined. Transfection of stem cells for gonads in the blastoderm or germinal crescent with plasmid vectors was observed. Positive primordial germ cells in the gonad were not observed by plasmid DNA microinjection into unincubated or 24hr incubated embryos in this study. However, the expression of plasmid DNA with RSVLTR promoter in the early chicken embryonic cell shows the possibility of transgenic chicken production by direct microinjection with plasmid DNA. Also genetic manipulation of chicken production traits such as disease resistance, growth and production may he possible in the future.
Immobilization of commercial acid phosphatases from wheat germ and potato onto ion exchangers
Lima Frederico Alves,Martins Pedro Alves,Wilson Galvão de Morais Júnior,Ribeiro Eloízio Júlio,Guisán José Manuel,de Resende Miriam Maria 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.9
A very simple and fast immobilization technique based on ion exchange was investigated to improve the thermal stability of acid phosphatase from wheat germ and potato. Immobilization was not efficient for the DEAE-sepharose, and MANAE-agarose supports. On the other hand, Toyopearl DEAE-650s proved to be a promising support, with immobilization yield above 95% and recovery of activity above 85% for both enzymes. A second step was introduced in the immobilization protocol to improve the thermal stability of these biocatalysts. For this, oxidation and reduction of glycosidic chains of acid phosphatase were carried out, allowing the formation of aldehyde groups and subsequent interaction with the amine groups to further stabilize the different forms (free and immobilized). Both biocatalysts showed residual activity after 1 hour of inactivation at the temperature of 60 °C, a fact not observed for the free enzyme. The wheat germ acid phosphatase derivative was the most stable, with residual activity of 66.7% for the only immobilized derivative and 76.2% for the oxidized/reduced derivative. Also, the derivatives prepared by ion exchange adsorption on Toyopearl (TOYO), followed by oxidation/reduction and intramolecular crosslinking, were approximately 15 and 41 times more stable than the free enzyme from wheat germ.