소 腎臟 Adenosine Deaminase Complexing Protein의 精製와 生物學的 性狀에 關한 硏究

김철호 인제대학교 1992 仁濟醫學 Vol.13 No.4

소의 신장 adenosine deaminase complexing protein을 순수 정제하였으며, 생물학적 성상에 관한 연구를 시도하였다. 그 결과 adenosine deaminase complexing protein은 adenosine의 농도에 따라 adenosine deaminase의 활성을 조절하는 역할을 할 것이라 사료된다. ADCP (adenosine deaminase complexing protein) was prepared and purified from bovine kidney. Its purification was done by the treatment of Triton X-100, followed by precipitation with sodium sulfate, ADA-Sepharose affinity chromatography and finally Sephadex G-100 gel filteration. The purified ADCP thus obtained is supposed to exist as a homodimer of molecular weight about 200 KD on SDS-polyacrylamide gel electrophoresis. The presence of ADCP caused a slight decrease in Km and Vmax value for adenosine, but the ADA (adenosine deaminase) binding with ADCP did not modify its behavior of optimal pH and temperature. No effects of varying metal ions, purine metabolites and its derivatives were observed on the activities of ADA in the presence of ADCP, except 6-chloropurine riboside inducing 27% decrease in activity and Fe2+ enhancing 29% of its activity. The binding of ADA with ADCP was optical at 1.7 : 1 molar ratio of ADA/ADCP with no effect of the addition of varying metal ions or purine metabolites except the guanosine and 2,6-diaminopurine, both causing aggravating complex with their concentration. The effect of ADCP on catalytic activity of ADA was studied. The slight elevation (up to 13%) of ADA catalytic activity was observed at the adenosine contents of 0.1∼0.2 mM and ADCP/ADA molar ratio of 1 : 1∼1 : 10, while the decrease in its activity was shown at the same range of adenosine contents, but ADCP/ADA molar ratio of 2 : 1∼10 : 1. The lower activities of ABA were also observed at lesser contents (0.01∼0.05 mM) of adenosine and the same molar ratio of ADCP/ADA. Thus it was shown that ADCP interacted with ADA. And the ADA activity tends to decrease at the physiological concentration of adenosine (about 0.01 mM). These results show that ADCP might play a role in the regulation of ADA activity.

방선균 J-144K가 생산하는 Adenosine Deaminase Inhibitor에 관한 연구

전홍기,김상웅,조영배,이인 부산대학교 유전공학연구소 1996 분자생물학 연구보 Vol.12 No.-

Adenosine deaminase의 새로운 저해제를 검색하기 위해 토양으로부터 adenosine deaminase 저해제를 생산하는 8균주의 방선균을 분리하였으며, 그중에서 저해활성이 가장 우수한 J-144K균주를 공시균주로 선정하였다. Adenosine deaminase 저해제 생산을 위한 최적배지 조성은 1.0% dextrose, 0.5% yeast extract, 0.5% peptone, 0.1% KH_2PO_4이었으며, 초적온도와 pH는 각각 30˚C와 7.0이었다. 이러한 조건에서 500ml용 진탕플라스크에 최적배지 100ml를 넣어 배양했을 경우 정지기인 배양 60시간째에 adenosine deaminade 저해활성이 가장 높게 나타났다. 분리균주 J-144K의 배양상등액으로부터 활성탄 흡착 및 유기용매 추출, Dowex 50 H^+ X-8 column chromatography, Dowex 1 Cl^- X-8 column chromatography, Sephadex G-15 gel filtration 등의 과정을 거쳐 adenosine deaminase 저해제를 정제한 결과, 3가지 종류의 저해제가 존재함을 알 수 있었다. In the screening of actinomycetes' culture filtrate for inhibitor of adenosine deaminase, a novel inhibitor was found in a cultured broth of strain J-144K. The optimum conditions for the adenosine deaminase inhibitor production from the isolated strain J-144K were evaluated. This strain showed the maximum yield of adenosine deaminase inhibitor when grown at pH 7.0 and 30˚C for 60 hours in the medium of 1.0% dextrose, 0.5% yeast extract, 0.5% peptone and 0.1 % KH_2PO_4 under the aerobic condition. Through the activated charcoal extraction, methanol fractionation, Dowex 50 H^+X-8 ion exchange column chromatography, Dowex Cl^- X-8 ion exchange column chromatography, and Sephadex G-15 gel filtration procedures, this inhibitor was purified with three materials.

Actinomycins에 의한 Adenosine Deaminase의 억제

김경자,조성진 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.3

Adenosine deaminase inhibitor was extracted from culture broth of Streptomyces sp. strain V-8 with ethylacetate. The ethylacetate extract showed the characteristic UV absorption spectrum of actinomycins at 40~450 nm. The ethylacetate extract was compared with respect to inhibitory behavior against adenosine deaminase from calf intestinal mucosa with acinomycin D, -C complex and actinomycin V. The K_i values for actnomycin D, -C complex, and actinomycin V against adenosine deaminase were determined to be 9.9×10 exp (-6) M, 9.6×10 exp (-6) M and 9.3×10 exp (-6) M, respectively. The K_i value for the ethylacetate extract of culture broth against adenosine deaminase was determined to be 5.7×10 exp (-6) M. The kinetic paramenters of actionmycin D, -C complex, -V and ethylacetate extract of culture broth for adenosine deaminase were as follows: I_50=1.5×10 exp (-5) M (actinomycin D), 2.7×10 exp (-5) M (actinomycin C complex), 3.5×10 exp (-5) M (actinomycin V), 8.9×10 exp (-6) M (ethylacetate extract of culture broth). The adenosine deaminase was inhibited noncompetitively by ethylacetate extract of culture broth as well as by actinomycine D, -C complex and actinomycin V.

Streptomyces sp. T-256의 세포의 Adenosine Deaminase의 성질

윤용균,이인,장태식 인제대학교 1994 仁濟醫學 Vol.15 No.4

Purine nucleotide의 대사계에 관련하는 aminohydrolase 가운데 adenosine deaminase는 동물 기원이 대부분이다. 미생물 기원의 효소에 대한 연구보고는 희소하며 특별히 세포외 효소로서의 adenosine deaminase 산생 미생물에 대한 보고는 극히 미진하다. 그러므로 본 실험은 미생물 기원 가운데서 Streptomyces T-256이 산생하는 세포의 adenosine deaminase의 효소학적인 성질에 대해서 검토하였다. Some properties of an extracellular adenosine deaminase produced from Streptomyces sp. Y-256 were examined after 30-80% of ammonium sulfate fractionation. The optimun pH and temperature for the stability of this enzyme were found to be near 7.0 and 40℃, respectively. The enzyme was stable in 0.05 M of potassium phosphate buffer. As results of examination for the enzyme activity to various pHs, the enzyme was generally highest in its activity near pH 7.0 but inactivated completely near pH 4.5 and pH 8.5. The enzyme activity to tempertures was highest near 37℃ andcompletely disappeared near 60℃. Of metal ions used 1 mM of Mg2+ increased slightly the enzyme activity, but 1 mM of α,α'-dipyridyl, NaCN and α-phenanthyoline, including 10mM of ethylendiaminetetraacetic acid, monoiodoacetate, pentachlorophenol and p-chloromercuric benzoate completely inhibited the enzyme activity.

방선균이 산생하는 세포외 Adenosine Deaminase의 특징

윤용균,이인,장태식 인제대학교 1993 仁濟醫學 Vol.14 No.2

Purine nucleotide의 대사계에 관련하는 aminohydrolase가운데 adenosine을 탈아미노화하여 inosine으로의 전환을 촉매하는 adenosine deaminase는 동물기원이 대부분이다. 따라서 미생물기원의 효소에 대한 연구보고는 희소하며 특별히 세포내 효소가 아닌 세포의 효소로서의 adenosine deaminase 산생 미생물에 대한 보고는 극히 미진하다. 그러므로 본 실험은 미생물 기원 가운데서 방선균이 산생하는 세포외 adenosine deaminase의 효소학적인 특성에 대해서 검토하였다. Some properties of an extracellular adenosine deaminase produced from Streptomyces sp. Y-225 were examined after 30∼80% of ammonium sulfate fractionation. The optimum pH and temperature for the stability of this enzyme were found to be near 7.0 and 40C, respectively. The enzyme was more stable in 0.05M of potassium phosphate buffer than 0.05M of tris-HCI buffer. As results of examination for the enzyme activity to various pHs, the enzyme was generally highest in its activity near pH 7.0 but inactivated completely near pH 4.0 and pH 8.5 The enzyme activity to tempertures was highest near 37℃ and completely disappeared near 60℃. Of metal ions used, 1 mM of Ba2+ increased slightly the enzyme activity, but 1 mM of Hg2+ and Ag2+ markedly inactivated the enzyme activity. I mM of α, α'-dipyridyl, NaCN and o -phenanthroline, including 10mM of ethylenediaminetetraacetic acid, monoiodoacetate, pentachlorophenol and p-chloromercuric benzoate completely inhibited the enzyme activity, but 0. lmM of NaF, NaN3 and monoiodoacetate slightly increased the enzyme activity.

곁사슬형 Polyethylene Glycol을 가진 Adenosine Deaminase 거대분자 결합체의 생화학적 특성

서선복,이순용 인제대학교 1995 仁濟醫學 Vol.16 No.4

혈색소, 홀몬 및 효소들과 같은 단백질은 질병 치료에 흔히 이용되고 있으나 이들은 생체 내로 투여하였을 때 치료제로서의 안정성과 항원성이 문제가 되어 그 효능을 기대하기 힘든 경우가 적지 않다. 저자들은 이러한 결점을 개선해 보고자 그 첫 단계로 비항원성 합성 고분자 화합물인 곁사슬형 polyethylene glycol(PEG)을 단백질의 실험모델로 사용한 효소 adenosine deaminase(ADA)에 결합시켜 이 복합체(PEG-ADA)의 물리적 및 생화학적 성질에 대하여 조사하였다. 연구 결과 곁 사슬형 PEG-ADA는 PEG로 인해 ADA가 변형되었지만, 효소활성이 유지되고 있었으며 단백질 분해효소에 대해서도 안정되어 있음을 보여 주었다. The enzyme is usually limited to use as a therpeutics because of its own instability and antigenicity. Adenosine deaminase(ADA), which was selected as a model of enzymes in this study, was modified by a pendant-type polyethylene glycol(PEG) in order to reduce the nzyme's own disadvantages, and the authors studied about the biochemical characteristics of the pendant type PEG-ADA conjugate to elucidate whether this conjugate could be a more improved and effective therapeutic enzyme haying stability and non-antigenicity. Calf adenosine deaminase was modified with pendant-type polyethylene glycol using cyanuric chloride as a coupler. The covalent attachmant of PEG to ADA altered the kinetic profile of the enzyme in which the value of Km for adenosine was decreased. The Km value of the ADA and PEG-ADA10 were 30 μM, 25 μM against adenosine, respectively. But the PEG-ADA20 exhibited reasonable retention of catvlytic activity with an increased Km, which was 50 μM against adenosine. The ADA and PEG-ADA showed optimum in acidic direction. The ADA and PEG-ADA had same temperture optima of 50℃. Thermal inactivation at the temperature above optima was essentially the same between the native and modified enzymes. PEG appeared to have no effect of stabilizing enzymes on high temperature. This suggested that PEG attachment caused some destabilization of the adenosine deaminase structure. PEG-ADA also demonstrated a resistance to the proteolytic digestion by trypsin and chymotrypsin. The electrophoretic mobility in polyacrylamide gels of PEG -ADA was reduced as compared to the native enzyme. The unmodified enzymes showed single band, whereas the modified ones formed a mumber of bands throughout the gels. The decreased electrophoretic mobility of PEG-ADA might be due to a charge-shielding effect of the hydrophilic PEG shell surrounding the enzyme. In addition, the increased size of the adducts might serve to retard migration in the polyacrylmide gels. The alteration of the pH dependance and the dramatically decreased mobility in polyacrylamide gel electrophoresis of the PEG-enzyme pointed up the effect of PEG modification on the apparent charge of the enzyme molecules. It was believed to be due to a change in conformation dictated by the charge of the PEG-enzyme or imposed by the covalent attachment of PEG to the enzyme. These results showed that the biochemical properties of adenosine deaminase were altered after chemical modification by pendant type PEG. The preparation of PEG-ADA retained the enzyme activity and had resistance against proteolytic enzymes. The authors concluded that the pendant-type PEG-ADA might be available in the medical field in the future.

Adenosine Deaminase를 생성하는 방선균의 특성

이인,윤용균,정관일 인제대학교 1992 仁濟醫學 Vol.13 No.1

Purine nucleotide의 대사계에 관련하는 aminohydrolase가운데adenosine을 탈아미노화 시켜 inosine으로의 전환을 촉매하는 adenosine deaminase는 동물기원이 대부분이다. 따라서 미생물기원의 효소에 대한 연구보고는 희소하며 특별히 세포내 효소가 아닌 세포의 효소로서의 adenosine deaminase산생 미생물에 대한 보고는 극히 미진하다. 그러므로 본 실험연구는 세포의 adenosine deaminase를 산생하는 방선균을 검색하고 그 분류학적 특성을 검토하는데 그 목표를 두었다. An actinomycete able to produce an extracellular adenosine deaminase catalyzing the conversion of adenosine to inosine by the deamination was isolated from sold samples. Examinations were made through the microscopic observation of shape, color of aerial and substrate mycelium, presence of soluble pigments, and assimilation of sugars. As the results obtained, the isolate showed good growth on the known test-media used for the classification of actinomycetes, and did simply branched-aerial hyphae with white color In general. The spore-bearing hyphae of isolate possessed spore chain and the color of substrate was brown, or yellow. Soluble pigments were also produced. The isolate produced the melanin pigment on peptone-yeast extractiron agar and presented high level of activity in gelatin liquefaction and nitrate reduction. From the above charactenstics and the presence of L,L-diaminopimelic acid as component of cell wall, she was identified genus Streptomyces and named Streptomyces sp. Y-225.

소아에서 결핵에 의한 흉수와 마이코플라즈마 폐렴에 의한 흉수 감별을 위한 흉수 Adenosine Deaminase의 유용성

최재형,허원경,백혜성,오재원,이하백 대한 소아알레르기 호흡기학회 2012 Allergy Asthma & Respiratory Disease Vol.22 No.4

Purpose:Determination of adenosine deaminase (ADA) in pleural fluid has been suggested as another tool to establish early diagnosis of tuberculous pleural effusion. However, there are few studies concerning its usefulness in children. The objective of this study was to evaluate the utility of the determination of ADA level in pleural fluid for the differential diagnosis between tuberculous pleural effusion (TPE) and Mycoplasma pneumonia with pleural effusion (MP) in children. Methods:We retrospectively reviewed the clinical records of 13 TPE patients and 21 MP patients with pleural effusion. Also, we analyzed ADA levels, and clinical, biochemical, microbiologic and cytologic findings in the pleural fluid. Results:The pleural fluid of all the subjects revealed exudative rather than transudate characteristics. The mean ADA level in the TPE group was significantly higher than that in the MP group (106.27±43.71 IU/L vs. 65.28±26.27 IU/L, P=0.003). The area under the curve in receiver operating characteristic analysis was 0.810. With a cut-off level for ADA of 60 U/L, the sensitivity, specificity, positive predictive value, and negative predictive value were 92.3%, 61.9%, 60.0%, and 92.9%, respectively. As many as 38.9% of patients with MP were false-positive with this ADA cut-off setting. Conclusion:Although the measurement of ADA activity in pleural fluid can help TPE diagnosis, we should consider that some cases of MP with pleural effusion showed high ADA activities. Accordingly, the utility of the ADA level in pleural fluid for the differentiation of TPE from MP declines and additional relevant studies are required. 목 적:흉막 액에서 adenosine deaminase (ADA) 활성도 측정은 결핵성 흉수의 진단에 유용한 검사로 제시되어왔다. 하지만 소아에서 ADA의 유용성에 대한 연구는 많지 않은 실정이다. 본 연구는 소아 부폐렴성 흉수에서 결핵성 흉수와 Mycoplasma pneumoniae 폐렴에 의한 흉수의 감별 진단을 위한 ADA 측정의 유용성을 알아보기 위해 본 연구를 시행하였다. 방 법:결핵성 흉수 환자 13례, 흉수를 동반한 M. pneumoniae 폐렴 환자 21례를 대상으로 임상 소견, 흉수의 생화학적, 미생물학적 및 혈액학적 검사, ADA치 등을 후향적으로 비교 분석하였다. 결 과:결핵성 흉수 환자 군의 ADA는 흉수를 동반한 M. pneumoniae 폐렴 환자 군의 ADA에 비해 통계적으로 유의하게 증가되어 있었다(106.27±43.71 IU/L vs. 65.28± 26.27 IU/L; P=0.003). 이들 측정값에 대한 receiver operating characteristic (ROC) 곡선 분석을 시행하였고 흉수 ADA 60 IU/L 이상일 때, 민감도, 특이도, 양성 예측도, 음성 예측도는 각각 92.3%, 61.9 %, 60.0%와 92.9%였다(ROC 곡선하 면적, 0.810; P=0.003). 흉수를 동반한 M. pneumoniae 폐렴 환자 군에서 ADA 60 IU/L 이상인 환자는 8명(38.1%)이었다. 결 론:흉수 내 ADA 증가는 결핵성 흉수의 진단에 도움이 될 수 있지만, 흉수를 동반한 마이코프라즈마 폐렴 환자에서도 ADA가 증가할 수 있으므로 두 질환을 감별하는데 유용성이 떨어진다 따라서 합당한 추가적인 검사가 더 필요하다.

Kinetics of Intracellular Adenosine Deaminase to Substrate Analogs and Inhibitors in Aspergillus oryzae

최혜선,Choi, Hye-Seon The Microbiological Society of Korea 1994 미생물학회지 Vol.32 No.1

Adenosine deaminase (ADA)의 여러 기질과 억제물질의 반응 속도론적 상수가 Aspergillusoryzae의 세포내 효소인 ADA의 활성자리에 어떻게 부착하고 어떤 요인을 필요로 하는지를 알기위해 측적되어졌다. kcat/$K_m$값에 의하면 조사된 기질로 작용하는 화합물 중에 3'-deoxyadenosine이 가장 좋은 기질로 작용하는 것으로 밝혀졌다. 몇 개의 유사체가 억제물질로 조사되었는데 purine riboside가 $3.7{\times}10^{-5}$M의 값 $K_i$값을 가지고 가장 강한 억베물질로 나타났다. Adenine은 기질로도 억제물질로도 작용을 못하므로 adenine의 N-9 위치의 ribose가 효소에 부착하는데 중요하다는 것을 시사하고 있다. 또 ADA는 6-chloropurine riboside(6-CPR)의 dechlorination을 촉매화하여 inosine과 Cl이온을 생성한다. 6-CPR의 ADA에 대한 기질 특이성은 정상 기질인 adenine의 0.86%로 측정되었다. ADA의 경쟁적 억제물질인 purine riboside는 비슷한 $K_i$값을 가지고 dechlorination도 억제하므로 deamination과 dechlorination 반응은 효소의 부착자리를 공유하고 있다고 생각되어진다. SH기에 작용하는 화합물중 수은제인 p-chloromercuribenzoate(PCMB), mersalyl acid, $HgCl_2$는 효소의 deamination 반응을 억제했다. Mersalyl acid에 의해 활성이 억제된 ADA는 thiol reagent인 dithiothreitol이나 2-mercaptoethanol에 의해 활성이 회복되지만 PCMB에 의해 억제된 효소는 회복되지 않았다. 각 수은제들이 억제물질로 작용할 때 $K_i$값과 억제양상이 측정되었는데 모두 경쟁적 방해를 보였다. $K_i$값은 10mM 인산완충용액에서 측정한 것이 100 mM 인산완충용액에서 측정한 것보다 훨씬 낮아 인산기가 기질이 아니어도 효소의 부착에 큰 영향을 미치는 것을 보여주고 있다. Kinetic parameters of various substrates and inhibitors were measured to elucidate the binding requirements of the active site of intracellular adenosine deaminase (ADA) in Aspergillus oryzae. 3'-Deoxyadenosine was the best substrate according to the value of relative kcat/$K_m$. Purine riboside was found to be the strongest inhibitor with the $K_i$ value of $3.7{\times}10^{-5}$M. Adenine acted neither as a substrate nor as an inhibitor, suggesting the presence of ribose at N-9 of adenosine was crucial to binding. ADA also catalyzed the dechlorination of 6-chloropurine riboside, generating inosine and chloride ions. Substrate specificity of 6-chloropurine riboside was 0.86% of adenosine. Purine riboside, a competitive inhibitor of ADA, inhibit the dechlorination with similar $K_i$ value, suggesting that the same binding site was involved in deamination and dechlorination. Among the sulfhydryl group reagents, mercurials, pchloromercuribenzoate (PCMB), mersalyl acid and $HgCl_2$ inactivated the enzyme. Mersalyl acid-inactivated ADA was reactivated by thiol reagents, but PCMB-inactivated enzyme was not. When ADA was treated with the mercurial reagents, the inhibition constants and inhibition patterns were determined. Each inhibition was competitive with substrate. The $K_i$ values of these mercurial reagents were lower in 10 mM phosphate buffer than in 100 mM phosphate buffer, showing phosphate dependency.

결핵성 및 비결핵성 흉막삼출액에서 TNF-$\alpha$ 농도의 진단적 의의

나현주,박석채,강광원,박형관,김영철,최인선,박경옥,Na, Hyun-Joo,Park, Seog-Chea,Kang, Kwang-Won,Park, Hyeong-Kwan,Kim, Young-Chul,Choi, In-Seon,Park, Kyung-Ok 대한결핵및호흡기학회 1997 Tuberculosis and Respiratory Diseases Vol.44 No.3

연구배경 : 결핵성 흉막염의 감별 진단 목적으로 널리 이용되고 있는 검사는 adenosine deaminase와 INF-$\gamma$를 세포성 면역에 또다른 중요한 매개체로 알려진 TNF-$\alpha$의 진단적 의의를 조사하고, 현재 임상에서 유용한 지표로 사용되고 있는 adenosine deaminase와의 감별력을 비교하고자 본 연구를 시행하였다. 방 법 : 삼출성 흉막염 80예(결핵성 : 39예, 암성 : 31예, 부폐렴흉막염 : 10예)를 대상으로 흉수의 기본적인 세포조성, 화학 검사와 더불어 ADA와 TNF-$\alpha$(Medgenix IRMA kit)를 측정하였다. 결 과 : 흉수내 ADA농도는 결핵성 흉막염에서 $48.7{\pm}32.7U/L$로 비결핵성 흉막염 $26.0{\pm}41.3U/L$에 비해 유의한 차이로 높았고(p < 0.05), TNF-$\alpha$치 또한 결핵성 흉막염에서 $184.1{\pm}214.2pg/mL$로 비결핵성 흉막삼출액 $44.1{\pm}114.2pg/mL$에 비해 유의하게 높았다(p < 0.01). ROC 곡선을 이용하여 ADA와 TNF-$\alpha$의 감별력을 가장 높일 수 있는 기준치를 정하였을 때, ADA는 30U/ml, TNF-$\alpha$는 15pg/ml로 측정되었고, 각각의 기준치를 이용하여 감수성과 특이도를 구하였을때, ADA는 감수성 66.7%, 특이도 85.0%, TNF-$\alpha$는 감수성 69.2% 특이도 87.1%를 보였다. 두 검사의 민감도와 특이도를 비교하기 위한 ROC 곡선에서, ROC 곡선아래의 면적(area under curve)은 ADA와 TNF-$\alpha$사이에 유의한 차이가 없었다(ADA 0.83, TNF-$\alpha$ 0.82). 다중회귀분석(multiple stepwise regression)에서 ADA가 가장 유용한 지표로 계산되었으나 TNF-$\alpha$의 추가가 분별력에 더 이상의 기여함은 없었다. 결 론 : 결핵성 흉막염과 비결핵성 흉막염을 감별 진단하는데 ADA와 함께 TNF-$\alpha$도 유용한 지표로 이용될 수 있으나 두가지 검사를 함께 시행함에 따른 진단에 있어서의 잇점은 없었다. Objectives : The differentiation of tuberculous effusion from the other causes of exudative pleural effusion remained difficult even with aids of biochemical analyses and pleural biopsy. As the pathophysiology of tuberculous pleural effusion is an enhanced cell mediated immunity, Adenosine deaminase(ADA) and various eytokines including Inteferon-$\gamma$, tumor necrosis factor alpha(TNF-$\alpha$) are considered as useful diagnostic tools in differentiating exudative pleural effusion. The author would like to demonstrate the diagnostic usefulness of TNF-$\alpha$ in the differentiation of exudative pleural effusion, and compared the discriminating ability of TNF-$\alpha$ with ADA. Methods : Pleural fluids obtained from 80 patients (tuberculous : 39, malignant : 31, parapneumonic : 10) with exudate pleural effusions were processed for cell counts and biochemical analysis including ADA and TNF-$\alpha$. Results : Tuberculous pleural fluid showed higher levels of ADA and TNF-$\alpha$, $48.7{\pm}32.7U/L$ and $184.1{\pm}214.2pg/mL$ than that of non-tuberculous effusion $26.0{\pm}41.3U/L$ and $44.1{\pm}114.2pg/mL$, respectively (ADA, TNF-$\alpha$, p < 0.05, p < 0.01). Receiver operating characteristics(ROC) curves were generated for ADA and TNF-$\alpha$ and the best cut-off value for adenosine deaminase and TNF-$\alpha$were considered as 30U/L and 15pg/ml, respectively. Comparing the area under the ROC curves, there was no significant difference between ADA and TNF-$\alpha$. Conclusion : For the differential diagnosis of tuberculous pleural effusion from the other causes of exudative pleural effusions, TNF-$\alpha$ as well as ADA was considered as useful diagnostic method. However adding TNF-$\alpha$ to ADA has no further diagnotic benefit than ADA alone.