• BMB Reports
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• 제30권6호
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• pp.403-409
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• 1997

Studies were undertaken to develop a competitive radioimmunoassay (RIA) and indirect antigen capture enzyme-linked immunosorbent assay (ELISA) for the determination of 5'-deoxy-5'-methylthioadenosine (MTA), which is formed from decarboxylated S-adenosylmethionine by spermidine and spermine synthase. Specific antiserum against MTA was raised in rabbits by immunization with MTA-BSA which was prepared by coupling BSA to oxidized MTA with periodate. Since MTA is oxidized easily to the sulfoxide, the sulfhydryl reagent, DTT. was added to the immunogen. For RIA, immunocomplexes were separated from free MTA by using ammonium sulfate precipitation. The antiserum showed almost no cross-reactivity with a variety of other nucleotides and riboses. But, the level of cross-reactivity of 5'-isobutylthioadenosine (SIBA) was high. These results showed the importance of hydrophobicity adjacent to the 5'-OH for determining antigenicity. The lower limit of detection by this assay was 100 fmol of MTA per tube. Using this assay. MTA levels were more easily and precisely determined in biological samples when compared with HPLC analysis. The RIA procedure is less time consuming. More than 24 analyses can be carried out in 2 h and required only a very small amount of sample ($20{\mu}l$ serum). In ELISA, biotin conjugated MTA-BSA was used as the labelled MTA. The sensitivity limit of this assay was lower than 100 pmol.

• 한국미생물·생명공학회지
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• 제26권6호
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• pp.558-561
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• 1998

식용버섯인 버들송이(Agrocybe cylindracea)로부터 새로운 생리활성물질을 탐색하던 중 버들송이 자실체의 methanol 추출물로부터 Diaion HP-20 column chromatography, ethyl acetate extraction 및 silica gel column chromatography를 행하여 AG 8을 분리하였다. 분리된 AG 8의 구조해석을 위하여 Mass, $^1$H 및 $^{13}$C NMR, irradiation실험 및 HMBC를 실시한 결과 분자량이 297, 분자식이 $C_{11}$ $H_{15}$$N_{5}$$O_3$S인 nucleoside계 화합물 5'-deoxy-5'-methylthioadenosine(MTA)으로 동정하였다. AG 8의 지질과산화 저해활성은 $IC_{50}$/ 값이 3.2 $\mu\textrm{g}$/$m\ell$ 이었으며 양성 대조구인 vitamin E보다 3배 정도 낮은 활성을 보여주었다. 본 화합물은 고등동물의 대사과정에 관여하는 효소 대사 조절물질로 고등동물을 비롯한 각종 생물체에 존재하는 것이 보고되었으나 담자균류로부터는 본 연구에 의하여 처음 분리되었다.

• BMB Reports
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• 제30권6호
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• pp.443-447
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• 1997

We have developed a novel method for assays of spermidine and spermine synthase (aminopropyltransferase) activities using antibody against 5'-deoxy-5'-methylthioadenosine (MTA). A new assay is reported here which is based on the observation that MTA is formed as a stoichiometric by-product of the spermidine and spermine synthases reactions. In order to determine MTA, a radioimmunoassay method with sensitivity and rapidity was used. (Lee and Cho, 1997). In this assay, adenine must be added in the reaction mixture, since it effectively inhibits the action of MTA phosphorylase by which MTA is metabolized. This assay is a improvement in term of sensitivity and time saving, compared to the currently used methods. It has a level of sensitivity (100 fmol) sufficient to monitor aminopropyltransferase activities in incubations containing as little as $10{\mu}g$ protein prepared from rat tissue homogenate. The results obtained showed that this method is particularly useful for cultured cells with low enzyme concentration. Moreover, this assay has the advantage which allows studies using alternative substrates (other amines). Spermidine synthase activity was high in rat liver, but low in rat kidney. The activity of spermine synthase was in most rat tissues very low as compared to that of spermidine synthase, but was high in brain.

• 한국미생물·생명공학회지
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• 제29권3호
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• pp.149-154
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• 2001

버섯유래 저분자 대사산물을 탐색하던 중 대전근교에서 채집한 젖비단 그물버섯(Suillus granulatus)으로 부터 9종의 화합물을 분리하였다. 젖비단 그물버섯을 메탄올로 추출한 후 용매분획하여 그 중 대산산물이 많이 함유된 chloro-form 층 및 ethyl acetate층 에 대하여 각각 silica gel 및 Sephadx LH-20 column chromatography를 수행하였다. 주요대사산물을 함유하고 있는 분획물을 TLC및 분취용 HPLC를 사용하여 정제한 결과 9종의 화합물을 분리하였다. 분리된 화합물의 화학구조를 규명하기 위하여 NMR 및 mass 분석을 수행하여쓰며 그 결과 이들의 화합물은 4-hydro-xyphenylacetic acid, 4-hydroxybenzaldhyde, 2, 5-dihydro-xybenzoic acid methyl ester, 5-deoxy-5 methylthioadeno- sine. indole 3-carboxlic methyl ester indole-3-carbox-aldehyde 1,3,5-trihydroxy 7-methylanthraquinone nicotinamide, 3-geranylgeranyl-4-hydroxybenzoic acid로 동정하였다.