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Pseudomonas syringae JP-MOK1으로부터 신규 phytase의 효소 정제 및 특성규명
최윤재 서울대학교 농업개발연구소 1999 농업생명과학연구 Vol.3 No.-
In animal feeds and nutrition, phytic acid(myo-inositol 1,2,3,4,5,6-hexakishydrogenphosphate) is the major storage form of phosphorus in plants such as cereal grains, legumes and oil seeds. But it has poor availability for monogastrics including pigs, poultry and humans due to the lack of digestive enzymes hydrolyzing the substrate. Phytate pass through the intestinal tract and is excreted in the feces. This causes envirionmental problems, so called, eutrophication, In addition, phytate forms insoluble complexes with nutritionally important metals such as iron, zinc, magnesium and calcium and also binds to proteins, thereby decreasing their bioavailability. In this study, a bacteria strain producing a phytase was isolated and identified as Pseudomonas syringae. Phytase enzyme was purified using ion exchange chromatography and its N-terminal amino acid sequence was determined as ADGYVLDV. Kinetic parameters was Km, 0.38mM and Vmax, 769U/mg. Specific activity of 649U/mg at 1mM Na-phytate in 50mM sodium acetate, pH5.6 and 40℃ was one of the highest known.
생쥐 유선에서의 Bcl-2 family 결합 단백질의 클로닝과 특성 규명
최윤재 서울대학교 농업개발연구소 2001 농업생명과학연구 Vol.5 No.-
We have screened mouse mammary gland cDNA library to search for A1 or BLK interacting protein using yeast two-hybrid system and obtained genes, mouse ING1 homolog (mINGh) and mouse DNA amplified in mammary carcinoma 1 (mDAM1), respectively. Cell death of HC11 cells, induced with serum starvation, was enhanced by mINGhs and the action of mINGhs was inhibited by A1 protien. mDAM1 also promoted cell death on the condition of serum starvation and transient coexpression of mDAM1 and BLK showed increased cell death compared to BLK expression alone in NMuMG cells. These results indicated that A1 can inhibit cell death not only via well known pathway related to Bcl-2 family but also through direct interacting with mINGh in the mammary epithelial cells and mDAM1 promotes mammary epithelial cell death and pro-apoptotic function of BLK.
신선유 생산을 위한 젖소내 유용 유전자원의 개발과 이용
최윤재 서울대학교 농업개발연구소 2000 농업생명과학연구 Vol.4 No.-
The purpose of this research was to obtain the selectively genes at the involution stage of bovine mammary gland, and to know their function whether these genes induce cell apoptosis or not. The bovine involution-induced cDNAs were isolated by subtractive hybridization method. We selected involution specific clones compared with lactation-specific clones using dot blot analysis. From this method we cloned bovine glycoprotein Ⅲ(clusterin), serum amyloid A3 protein, WDNM1 protein. Three clones were further confirmed to be specifically expressed in involution stage by Northern blot analysis. And we cloned full sequence these three cDNAs. Expression vectors for these cDNA containing full-coding region were constructed into pIRES, expression vector. These expression vectors were transfected into mammary epithelial cell line, HC11 cells. The transfectants were further confirmed by RT-PCR. To further characterize regulated expression of these genes ininvitro system, we treated death inducing agents in HC11. Finally, glycoproteinⅢ, serum amyloid A3 and WDNM1 recombinant proteins were produced in E. coil using pET-expression vectors system.
Hwang, Seongsoo,Choi, Eun Joo,You, Seungkwon,Choi, Yun-Jaie,Min, Kwan-Sik,Yoon, Jong-Taek Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.11
This study was performed to determine the developmental potentials of nuclear transfer (NT) embryos using life-span extended cells transfected with a foreign gene as donor cells. A life-span extended bovine embryonic fibroblast cell line was transfected with an expression vector in which the human type II collagen (BOMAR) and ear fibroblasts were used as a donor cell. Cytogenetic analysis was performed to analyze the chromosomal abnormality of donor cells. The fusion rate of 1.8 kV/cm for $15{\mu}sec$ given twice was significantly higher than that of other groups (p<0.05) and the embryos lysed were significantly higher after 1.8 kV/cm for $20{\mu}sec$ given once compared to other groups (p<0.01). The blastocyst development in the ear cell group was statistically significant compared to both BOMAR groups (p<0.01). Both BOMAR groups cultured more than 40 passages (>40 passages) had a lower number of chromosomes; however, fresh granulosa cell (GC) and BOMAR groups cultured less than 20 passages had normal chromosome numbers. Both >40 passages BOMAR groups had numerous obscure debris in metaphase spreads. The transfected foreign gene was expressed in all BOMAR groups, but not in the GC group. Based on these results, the lower developmental potential of NT embryos using life-span extended donor cells transfected with a foreign gene might be a cause of chromosomal abnormality in donor cells.
Min, Hae Ki,Choi, Yun Jaie,Cho, Kwang Keun,Ha, Jong Kyu,Woo, Jung Hee 한국미생물 · 생명공학회 1994 Journal of microbiology and biotechnology Vol.4 No.2
The β-1,4-endoglucanase gene from Actinomyces sp. 40 was cloned into Escherichia coli DH5α with pUC19. Chromosomal DNA from Actinomyces sp. 40 was cleaved with the restriction enzyme Sau3Al and ligated into pUC19 for the transformation of Escherichia coli DH5α. Positive clones of β-1,4-endoglucanase gene were detected as the clear zones on a medium supplemented with carboxymethylcellulose (CMC). This transformant possessed a single plasmid, designated pDS1, which contained the vector DNA and a 3.5 kilobase (kb) Sau3Al insertion fragment encoding endoglucanase. The size of the cloned fragment was reduced to 2.0 kb. The endoglucanase activity produced by the E. coli DH5a (pDS6) was higher than that of Actinomyces sp. 40 strain. The optimum pH and temperature of the cloned enzyme were pH 4.0∼5.0 and 55℃, respectively. The cloned enzyme was stable at 55℃ or below and in buffer ranging from pH 4.0 to 7.0. The enzyme degraded CMC but did not degrade xylan, cellobiose, and methyl-umbelliferylcellobiopyranoside (MUC).
Review : Microencapsulation of Live Probiotic Bacteria
( Chong Su Cho ),( Yun Jaie Choi ),( Cheol Heui Yun ),( Islam Mohammad Ariful ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.10
Scientific research regarding the use of live bacterial cells for therapeutic purposes has been rapidly growing over the years and has generated considerable interest to scientists and health professionals. Probiotics are defined as essential live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Owing to their considerable beneficial health effects, these microorganisms are increasingly incorporated into dairy products; however, many reports have demonstrated their poor survival and stability. Their survival in the gastrointestinal tract is also questionable. To overcome these problems, microencapsulation techniques are currently receiving considerable attention. This review describes the importance of live probiotic bacterial microencapsulation using an alginate microparticulate system and presents the potentiality of various coating polymers such as chitosan and polylysine for improving the stability of this microencapsulation.