• Journal of Applied Biological Chemistry
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• 제50권3호
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• pp.109-114
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• 2007

Sar1p is a ras-related GTP-binding protein that functions in intracellular protein transport between the endoplasmic reticulum (ER) and the Golgi complex. The effector domain of Ras family proteins is highly conserved and this domain is functionally interchangeable in plant, yeast and mammalian Sar1. Using a recombinant Brassica sar1 protein (Bsar1p) harboring point mutations in its effector domain, we here investigated the ability of Sar1p to bind and hydrolyze GTP and to interact with the two sar1-specific regulators, GTPase activating protein (GAP) and guanine exchange factor (GEF). The T51A and T55A mutations impaired Bsar1p intrinsic GTP-binding and GDP-dissociation activity. In contrast, mutations in the switch domain of Bsar1 did not affect its intrinsic GTPase activity. Moreover, the P50A, P54A, and S56A mutations affected the interaction between Bsar1p and GAP. P54A mutant protein did not interact with two regulating proteins, GEF and GAP, even though the mutation didn't affect the intrinsic GTP-binding, nucleotide exchange or GTPase activity of Bsar1p.

• 대한임상검사과학회지
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• 제38권1호
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• pp.54-58
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• 2006

To find out the effectiveness of clinical examination for the diagnosis of respiratory tuberculosis, a 78 respiratory tuberculosis patient,s group was matched by sex and age with 78 control healthy subjects. In the result of blood chemistry, mean values of $123.5{\pm}62.04mg/dL$ in glucose, $429.01{\pm}150.77IU/L$ in LDH, and $44.51{\pm}43.76IU/L$ in ${\gamma}$-GTP, were higher than that of the controls (healthy subjects), and $3.51{\pm}0.68mg/dL$ in albumin was lower than that of the controls. In the result of the haematology examination, mean values of $12.52{\pm}3.27g/dL$ in hemoglobin, $36.72{\pm}7.28%$ in hematocrit, and $24.61{\pm}12.36%$ in lymphocyte, were lower than that of the controls, $9.23{\pm}5.25%$ in monocyte $78.30{\pm}37.35mm/hr$ in ESR, and $48.45{\pm}35.15U/L$ in ADA were higher than that of the controls. For the comparisons of the tuberculosis patients values from normal reference values, 22.2% in glucose, 22.4% in LDH, 25.0% in ${\gamma}$-GTP, 35.4% in albumin, 88% in ESR, and 88.6% in ADA, showed abnormal values. We concluded that the values of glucose, ${\gamma}$-GTP, albumin, WBC, RBC, hemoglobin, hematocrit, lymphocyte, monocyte, ADA, and the ESR were useful in tuberculosis diagnosis.

• 대한약리학회지
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• 제32권2호
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• pp.151-158
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• 1996

Following the subcutaneous administration of $R(-)N^6-(2-phenylisopropyl)adenosine(600\;nmol/kg/hr)$ to rats for 1 week using t$Alzet^{\circledR}$ mini-osmotic pumps, $A_1$ adenosine receptor functions were determined using $[^3H]DPCPX$ binding, $[^{35}S]GTP_{\gamma}S$ binding, and adenylyl cyclase assays. $A_1$ adenosine receptor binding and the inhibition of adenylyl cyclase activity by PIA was not altered in cerebrocortical membranes prepared from PIA-treated rats. However, there was a significant decrease in the $A_1$ adenosine receptor-mediated stimulation of $[^{35}S]GTP_{\gamma}S$ binding to cerebrocortical membranes prepared from PIA-treated rats(22.0% decrease in basal activity; 19.7% decrease in maximal activity). These results suggest that the desensitization of $A_1$ adenosine receptors following chronic administration involves agonist-induced uncoupling of the receptors from G proteins rather than alteration of $A_1$ adenosine receptor molecules. It is also suggested that the determination of stimulation of $[^{35}S]GTP_{\gamma}S$ binding to G proteins is a suitable tool in studying the receptor regulation including desensitization

• 미생물학회지
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• 제38권3호
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• pp.173-179
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• 2002

발광 박테리아인 Photobacterium species의 lux 오페론에서 발견된 riboflavin 생합성에 관여하는 유전자들(ribI,II,III,IV)의 기능을 조사하였다. 대장균에서 이들 유전자가 포함된 재조합 플라스미드를 발현시켰을 때 상당량의riboflavin이 합성되는 것을 확인하였으며, 또한 이들 유전자들(ribI,II,III,IV)의 기능을 riboflavin에 대하여 종속 영양체인 대장균 돌연변이주(BSV 11,18)를 이용한 유전학적인 방법과 생화학적 방법으로 분석한 결과, 이들은 각각 riboflavin synthase, 3,4-dihydroxy-2-butanone 4-phosphate (DHBP) synthase, lumazine synthase, GTP cyclohydrolase II활성도를 갖는 단백질을 코드하는 것으로 밝혀졌다. 이는Photobacterium species의 riboflavin 유전자 체계가 riboflavin 생합성에 관여하는 모든 5개의 유전자들이 한 오페론에 존재하는 Bacillus subtilis와 주요 riboflavin 유전자들이 분리되어 있는 대장균과는 다른, 중간적인 형태를 갖는다는 것을 나타낸다.

• 대한원격탐사학회지
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• 제36권6_2호
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• pp.1567-1577
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• 2020

시가화 지역 토지피복분류는 도시계획 및 관리에 활용된다. 따라서, 시가화 지역에 대한 분류 정확도 향상 연구는 중요하다고 할 수 있다. 본 연구에서는 고해상도 위성영상인 KOMPSAT-3A을 기계학습 중 Support Vector Machine(SVM)과 Artificial Neural Network(ANN)을 기반으로 시가화지역 분류를 진행하였다. 훈련 데이터 구축과정에서 25 m 격자를 기반으로 훈련 지역을 구분하여 영상을 학습하였으며, 학습된 모델을 활용하여 테스트 지역을 분류하였다. 검증과정에서 250개의 GTP를 활용하여 오차 행렬을 통한 결과를 제시하였다. SVM 4가지 기법과 ANN 2가지 기법 중 SVM Polynomial Model이 가장 높은 정확도인 86%를 나타냈다. Ground Truth Points(GTP)를 활용하여 두 개의 모델을 비교하는 과정에서, SVM 모델은 전체적으로 ANN 모델보다 효과적으로 KOMPSAT-3A 영상을 분류하였다. 건물, 도로, 식생, 나대지 4가지 클래스 분류 중 건물이 가장 낮은 분류정확도를 보여주었으며, 이는 고층건물에 따른 건물 그림자에 의한 오분류가 주요 원인으로 나타났다.

• Molecules and Cells
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• 제27권5호
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• pp.583-589
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• 2009

GTP cyclohydrolase I (GTPCH) is a key enzyme in the de novo synthesis of tetrahydrobiopterin. Previously, the Drosophila melanogaster GTPCH gene has been shown to be expressed from two different promoters (P1 and P2). In our study, the 5'-flanking DNA regions required for P1 and P2 promoter activities were characterized using transient expression assay. The DNA regions between -98 and +31, and between -73 and +35 are required for efficient P1 and P2 promoter activities, respectively. The regions between -98 and -56 and between -73 and -41 may contain critical elements required for the expression of GTPCH in Drosophila. By aligning the nucleotide sequences in the P1 and P2 promoter regions of the Drosophila melanogaster and Drosophila virilrs GTPCH genes, several conserved elements including palindromic sequences in the regions critical for P1 and P2 promoter activities were identified. Western blot analysis of transgenic flies transformed using P1 or P2 promoter-lacZ fusion plasmids further revealed that P1 promoter expression is restricted to the late pupae and adult developmental stages but that the P2 promoter driven expression of GTPCH is constitutive throughout fly development. In addition, X-gal staining of the embryos and imaginal discs of transgenic flies suggests that the P2 promoter is active from stage 13 of embryo and is generally active in most regions of the imaginal discs at the larval stages.

• Journal of Nutrition and Health
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• 제31권8호
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• pp.1217-1225
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• 1998

This study was conducted to investigate the effects of shellfish on lipid metabolism in rats fed high fat supplements. Male sprague-dawley rats weighting approximately 165g were fed a basal diet, a high fat diet, or a high fat diet plus shellfish for 4 weeks. The shellfishes on the were oyster, hard-shelled mussel, little neck clam, and march clam. Alfter 4 weeks high fat diet, supplementation of 20% lard significantly increased plasma. GOT, GPT, ${\gamma}$-GTP , and liver triglyceride (TG). Plasma GOT, GPT, ${\gamma}$-GTP , triglyceride, and total cholestrerol levels were significantly lower in shellfish groups than in basal and high-fat groups regardless of high-fat supplementation (p<0.05). The total lipid and cholesterol content in liver showed similar results(p<0.05). There were no differences in glucose, HDL-cholesterol in plasma and total cholesterol and total lipid in liver between basal and high-fat supplemented diets. Liong chain fatty acids, specific components of shellfishes group, were exclusively higher than in basal and high-fat diets, and were most well-reflected in liver and plasma. From the above results, the hypolipidemic effects of shellfish were detected in the process of inducing hyperlipidemia by high-fat supplement.

• 대한한방내과학회지
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• 제21권1호
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• pp.108-115
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• 2000

Objective : To investigate the hepatoprotective effects of Gami-oryungsan on the liver damage induced by bromobenzene. Method : The development of fibrosis and acute liver injury was examined by the chemical analysis of AST, AL T, ${\gamma}$-GTP . and epoxide hydrolase glutathione S-transferase glutathione peroxidase enzyme activity, lipidoperoxide levels, glutathione levels were measured and oberved. Results : The increasing levels of lipidoperoxide was decreased proportionally according to dose of extract GO. Epoxide hydrolase glutathioneS-transferase glutathione peroxidase enzyme activity highly increased in GO pre-acupunctured group compared with the group treated with only bromobenzene. The increase of serum AST, AL T, ${\gamma}$-GTP enzyme activity of mice by bromobenzene was inhibited by the administration of GO. Lipidoperoxide levels in rat's liver decreased compared to the case of bromobenzene-treated group. The levels of Glutathione decreased by bromo benzene were increased highly in GO pre-acupunctured group. Conclusion : These results suggest that GO extract recovers the damage of liver due to bromobenzene intoxication by decreasing the lipid peroxidation AST AL T ${\gamma}$-GTP enzyme activity and increasing epoxide hydrolase glutathioneS-transferase glutathione peroxidase enzyme activity, glutathione levels.

• BMB Reports
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• 제41권7호
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• pp.555-560
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• 2008

The interaction of the rod GTP binding protein, Transducin ($G_t$), with bleached Rhodopsin ($R^*$) was investigated by measuring radiolabeled guanine nucleotide binding to and release from soluble and/or membrane-bound Gt by reconstituting $G_t$ containing bound GDP ($G_t$-GDP) or the hydrolysis-resistant GTP analog guanylyl imidodiphosphate ($G_t$-p[NH]ppG) with $R^*$ under physiological conditions. Release of GDP and p[NH]ppG from $G_t$ occurred to the same extent and with the same light sensitivity both in the presence and absence of added GTP. Significant amounts of $G_t$ without bound nucleotide ($G_{t^-}$) were generated. When ROS containing bleached rhodopsin ($R^*$) were centrifuged in low ionic strength buffer, $G_{t^-}$ remained associated with the membrane fraction, whereas $G_t$-GDP remained in the soluble fraction. These results suggest that $G_t$-GDP and $G_t$-p[NH]ppG have similar affinities for $R^*$. The results also suggest that $G_{t^-}$, rather than $G_t$-GDP, is the moiety which exhibits tight, "light-induced" binding to rhodopsin.

• 한국미생물·생명공학회지
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• 제40권3호
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• pp.274-277
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• 2012

본 연구에서는 다제내성을 보이는 인체 병원균의 하나인 S. aureus에서 유래된 FtsZ 단백질의 유전자를 클로닝하고 대장균에 형질전환하여 재조합 단백질을 만들고, in vitro 상에서 폴리머 형성 활성을 측정하였다. Bradford 방법을 이용하여 SA FtsZ단백질의 농도를 측정한 후, SA FtsZ단백질의 폴리머 형성 활성을 확인하기 위해 형광계를 이용하여 excitation 방향과 $90^{\circ}$의 방향에서 산란되는 빛의 양을 측정하는 방법을 사용하였을 때에 대조군에서는 빛이 산란되지 않았고, SA FtsZ 단백질에 GTP와 $Mg^{2+}$를 처리한 실험군에서만 빛이 산란되는 현상을 관찰하였다. 1분여의 시간이 지난 이후에는 다시 산란되는 빛이 줄어드는 것을 볼 수 있는데, 이것은 SA FtsZ 단백질의 아미노말단 도메인의 GTPase 활성에 의해서 GTP가 분해되어서 SA FtsZ 단백질의 폴리머가 단량체로 분해되었기 때문이라고 예측된다. 본 연구를 통하여 확립된 SA FtsZ 활성 측정 방법은 향후 SA FtsZ 단백질의 폴리머 형성을 저해하는 방식으로 S. aureus를 표적으로 하는 항생제 후보물질 도출을 위한 스크리닝 방법으로 사용될 수 있을 것이다.