• Journal of Microbiology and Biotechnology
• /
• 제24권7호
• /
• pp.998-1003
• /
• 2014

Aspartate aminotransferase (AST; E.C. 2.6.1.1), a vitamin B6-dependent enzyme, preferentially promotes the mutual transformation of aspartate and ${\alpha}$-ketoglutarate to oxaloacetate and glutamate. It plays a key role in amino acid metabolism and has been widely recommended as a biomarker of liver and heart damage. Our study aimed to evaluate the extensive preparation of AST and its application in quality control in clinical laboratories. We describe a scheme to express and purify the 6His-AST fusion protein. An optimized sequence coding AST was synthesized and transformed into Escherichia coli BL21 (DE3) strain for protein expression. Ideally, the fusion protein has a volumetric productivity achieving 900 mg/l cultures. After affinity chromatography, the enzyme activity of purified AST reached 150,000 U/L. Commutability assessment between the engineered AST and standard AST from Roche suggested that the engineered AST was the better candidate for the reference material. Moreover, the AST showed high stability during long-term storage at $-20^{\circ}C$. In conclusion, the highly soluble 6His-tagged AST can become a convenient tool for supplying a much better and cheaper standard or reference material for the clinical laboratory.

• 한국환경과학회지
• /
• 제22권7호
• /
• pp.855-862
• /
• 2013

Although antioxidant activities of Korean traditional fermented foods were reported by many researchers, study on antioxidant activity of microorganism originated from Korean traditional fermented foods was little. Therefore, we improved condition for antioxidant production by a bacterium isolated from home-made Chungkookjang. We selected a bacterial strain, which showed the highest antioxidative activity, from Chungkookjang and then named GJ. The selected GJ strain was identified as Bacillus methylotrophicus by alignment data of 16S rRNA gene nucleotide sequences. Improved medium compositions for DPPH radical scavenging activity were 0.25% sucrose, 1% peptone, 0.01% $MgSO_4{\cdot}7H_2O$ and initial pH 6.5, respectively. Optimal culture conditions were $30^{\circ}C$, 200 rpm and 4% inoculum volume, respectively. In improved conditions, DPPH radical scavenging activity of GJ reached to 91% in a short time. The strain GJ also possessed ACE inhibition and other antioxidative activities; ACE inhibition activity (49.4%), ABTS radical scavenging activity (99.8%), metal chelating activity (67.9%), SOD-like activity (36.5%) and reducing power ($A_{700}$ = 5.982) were observed, respectively. Therefore, our results suggest that B. methylotrophicus GJ strain may be potential candidate for functional foods, cosmetic products for anti-aging and medicine for diseases caused by oxidative stress.

• 대한의생명과학회지
• /
• 제26권1호
• /
• pp.28-36
• /
• 2020

High blood pressure (HTN) is a condition in which blood pressure is kept higher than normal. Blood pressure trait measures systolic blood pressure (SBP) which is the highest pressure and diastolic blood pressure (DBP) which is the lowest blood pressure. Pulse pressure (PP) is the difference between systolic and diastolic blood pressure. Hypertension is known as a disease caused by the interaction of the environment and genetic factors. To date, studies have been conducted to find genes associated with hypertension. Genome-Wide Association Study (GWAS) analysis using European data from the UK Biobank reported new 535 loci were associated with blood pressure trait. Among them, 12 genes have been reported to have a significant correlation with SBP, DBP and PP. In the study, 12 genes polymorphisms were extracted based on KARE (Korean association resource) and then we performed linear regression of blood pressure trait. As a result, 6 SNPs of the 3 genes (rs12355413 and rs11006736 of ARMC4, rs2290883, rs2290884 and rs11039014 of LRP4, rs7234941 of BCL2) showed statistically significant correlation (P<0.05) with blood pressure trait. Of the 3 genes, 6 SNPs in 2 genes (rs9651357, rs12355413, rs11006736, rs1889522 of ARMC4 and rs4987774, rs7234941 of BCL2) showed significant correlation with hypertension. These results suggest that genetic polymorphisms of ARMC4, LRP4 and BCL2 genes are associated with blood pressure traits and hypertension in Korean population. Moreover, we expected to help understand the pathogenesis of hypertension.

• 약학회지
• /
• 제49권2호
• /
• pp.147-150
• /
• 2005

Macrophage scavenger receptors (MSRs) induce microglial interaction with ${\beta}$-amyloid fibrils (fA${\beta}$) that are associated with Alzheimer's disease (AD). Although microglia are know n to have a dual effect on formation of plaque and clearance of fA${\beta}$ in the AD brain, receptor-mediated phagocytosis is a very important tool for preventing amyloid plaque via activated microglia in the early stage of AD. In the study, we examined whether ginsonoside Rg3 enhances the microglial Phagocytosis of A${\beta}$1-42 through Phagocytosis assay, gene expression (RT-PCR) and protein assay (western blots) for the cell responsiveness presented between Rg3-treated and non-treated groups. Fluro-labeled Ac-LDL and E.coli particles were used as control proteins for phagocytosis. In previous studies, this was a particularly interesting property of Rg3 in the stimulation and phagocytosis of macrophages in the periphery. We report here that ginsenoside Rg3 increased the expression of type-A MSR (MSR-A) in microglia and thus accelerated the phagocytosis with an effective degradation of engulfed fA${\beta}$. This result suggests that Rg3 may play an important role in removing fA${\beta}$ by enhancing the receptor-mediated phagocytosis. In addition, Rg3 could be a potential candidate for balancing the rate of production of fA${\beta}$ in AD brain.

• 미생물학회지
• /
• 제50권4호
• /
• pp.327-333
• /
• 2014

산성 배지에서 성장하며 mannanase를 생산하는 균으로 분리된 Bacillus sp. YB-1401과 B. amyloliquefaciens YB-1402로부터 mannanase 유전자를 각각 클로닝하고 그 염기서열을 분석한 결과 2개 유전자는 동일하게 360 아미노산으로 구성된 단백질을 코드하며 1,080 뉴클레오티드로 구성되어 있다. 아미노산 잔기 배열의 유사성을 분석한 결과 이들 mannanases는 서로 4개의 잔기가 다르며 glycosyl hydrolase family 26에 속하는 mannanase와 상동성이 높았다. 재조합 대장균이 생산하는 YB-1402 유래의 His-tagged mannanase (HtMAN1402)가 YB-1401 유래의 His-tagged mannanase (HtMAN1401)에 비해 열안정성과 산성 pH에서 안정성이 높았다. 특히 HtMAN1402는 pH 3.0에서 4시간 방치 후에도 약 50% 이상의 잔존활성을 보여 사료첨가용 효소로 사용되기에 적합한 특성을 보였다. 또한 이들 효소는 $Ca^{2+}$ 이온에 의해 열안정성이 증가하는 것으로 확인되었다.

• 한국환경과학회지
• /
• 제19권10호
• /
• pp.1307-1314
• /
• 2010

This study was conducted to isolate and characterize a novel feather-degrading bacterium producing keratinase activity. A strain K9 was isolated from soil at poultry farm and identified as Xanthomonas sp. K9 by phenotypic characters and 16S rRNA gene analysis. The cultural conditions for the keratinase production were 0.3% fructose, 0.1% gelatin, 0.04% $K_2HPO_4$, 0.06% $KH_2PO_4$, 0.05% NaCl and 0.01% $FeSO_4$ with an initial pH 8.0 at $30^{\circ}C$ and 200 rpm. In an optimized medium containing 0.1% chicken feather, production yield of keratinase was approximately 8-fold higher than the yield in basal medium. The strain K9 effectively degraded chicken feather meal (67%) and duck feather (54%), whereas human nail and human hair showed relatively low degradation rates (13-22%). Total free amino acid concentration in the cell-free supernatant was about 25.799 mg/l. Feather hydrolysate produced by the strain K9 stimulated growth of red pepper, indicating Xanthomonas sp. K9 could be not only used to increase the nutritional value of chicken feather but also a potential candidate for the development of natural fertilizer applicable to crop plant soil.

• Journal of Microbiology and Biotechnology
• /
• 제16권4호
• /
• pp.556-561
• /
• 2006

The HOX genes coding homeodomain proteins have been suggested as a candidate molecular switch that determines the fates of cells during embryonic development and patterning. It is believed that a set of differentiation-specific HOX genes enter into a turn-on state during tissue differentiation, in contrast to stem cell-specific HOX genes that enter into a turn-off state. However, comprehensive data of expression profiles of HOX genes in human embryonic stem cells (hESC) and differentiated embryonic tissues are not available. In this study, we investigated the expression patterns of all 39 HOX genes in hESC and human fetal tissues and analyzed the relationships between hESC and each tissue. Of the 39 genes, 18 HOX genes were expressed in stem cells, and diverse expression patterning was observed in human fetal tissues when compared with stem cells. These results indicate that HOX genes could be main targets for switching of stem cell differentiation into tissues.

• 한국한의학연구원논문집
• /
• 제8권1호
• /
• pp.109-126
• /
• 2002

The herbal extract (YMT_02) is a modified herbal extracts from Yukmijihwangtang (YMJ) to promote memory-enhancing. The YMJ extracts has been widely used as an anti-aging herbal medicine for hundred years in Asian countries. The purpose of this study is to; 1) quantitatively evaluate the memory-enhancing effect of YMT_02 by hehavior task, 2) identify candidate genes responsible for enhancing memory by cDNA microarray and 3) assess the anti-oxidant effect of YMT_02 on PC12 cell. Memory retention abilities are addressed by passive avoidance task with Sprague-Dawley (SD) male rat. Before the training session, the rats are subdivided into four groups and administrated with YMT_02, Ginkgo biloba, Soya lecithin and normal saline for 10 days. The retention test was performed. 24 hours after the training session. The retention time of the YMT_02 group was significantly (p<0.05) delayed $({\sim}100%)$, whereas Ginkgo biloba and Soya lecithin treatment delayed 20% and 10% respectively. The hippocampi of YMT_02 and control group were dissected and mRNA was further purified. After synthesizing cDNA using oligo-dT primer, the cDNA were applied and mRNA was further purified. After synthesizing cDNA using oligo-dT primer, the cDNA were applied to Incyte rat GEMTM 2 cDNA microarray. The microarray results show that prealbumin(transthyretin), phosphotidy lethanolamine N-methyltransferase, and PEP-19 are expressed abundantly in the YMT_02 treated group. Especially, PEP-19 is a neuron-specific protein, which inhibits apoptotic processes in neuronal cell. On the other hand, transcripts of RAB15, glutamate receptor subunit 2 and CDK 108 are abundant in control group. Besides, neuronal genes involved in neuronal death or neurodegeneration such as neuronal-pentraxin and spectrin are abundantly expressed in control group. Additionally, the YMT_02 shows an anti oxidative effect in the PC12 cell. The list of differentially expressed genes may implicate further insight on the action and mechanism behind the memory-enhancing effect of herbal extracts YMT_02, for example, anti-apoptotic, anti-oxidative, and neuroprotective effects.

• 한국수정란이식학회지
• /
• 제18권3호
• /
• pp.227-235
• /
• 2003

한우의 mt DNA cytochrome oxidase subunit I, II, 및 III complex지역의 유전적 다형현상을 제한효소를 이용하여 검출하였다. PCR primer 6종에 대하여 20가지 제한효소를 처리하였으며, Pst I, Pvu II, Rsa I, Eco RI, Bgl II, and Msp I 제한효소를 사용하여 유전적 변이를 검출하였다. 검출된 변이체와 한우의 성장과의 관련성을 조사한 결과 cytochrome oxidase subunit III complex 지역의 유전염기서열을 근거로 제작한 primer Mt9 좌위에서 제한효소 PvuII를 이용한 절단형과 체중형질 인 WT15(P<0.05) 및 WT18(P<0.01)에서 고도의 유의성이 관찰되었다. 아울러 , Mt9-Pvu II(P=0.07), Mt6-Bgl II(P=0.05), and Mt8-Rsa I(P=0.05) 좌위 또한 WT9, WTl5, and WT15에서 각각 통계적 유의성이 관찰되었다. 따라서 본 결과는 cytochrome oxidase subunit III complex segments가 candidate gene으로서 기초적 유전정 보 제공은 물론 유전적 개량을 위해 사용될 수 있을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
• /
• 제26권6호
• /
• pp.1067-1076
• /
• 2016

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30℃ and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0℃ and good stability at temperatures below 35℃. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30℃. Its activity was slightly affected by some metal ions such as K⁺, Ca²⁺, and Na⁺. The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.