• KSBB Journal
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• 제24권1호
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• pp.65-69
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• 2009

본 연구에서 탄소원이 고갈된 후 용존산소농도로 epothilone의 합성을 조절할 수 있음을 증명하였다. 선행연구로써, soluble starch를 탄소원으로 결정하였고, lactose와 yeast extract의 최적농도가 각각 4 g/L, 0 g/L임을 알 수 있었다. 탄소원이 고갈된 환경에서 산소농도가 낮을 경우 균체가 epothilone을 다량으로 합성하였다. 산소 공급을 조절할 수 없는 flask의 경우 배양이 진행되면서 균제농도가 증가하고 자연적으로 산소 농도도 감소하므로 epothilone이 합성되지만, 생물반응기의 경우 탄소원의 고갈 후 산소 농도를 최대한 낮게 유지시키는 것이 epothilone의 생산을 증가시켰다.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.135-137
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• 2008

The metabolic engineering of epothilones, as secondary metabolites, was investigated using Sorangium cellulosum to achieve the selective production of epothilone B, a potent anticancer agent. Thus, the propionyl-CoA synthetase gene (prpE) from Ralstonia solanacearum was heterologously expressed in S. cellulosum to increase the production of epothilone B. Propionyl-CoA synthetase converts propionate into propionyl-CoA, a potent precursor of epothilone B. The recombinant S. celluloslim containing the prpE gene exhibited a significant increase in the resolution of epothilones B/A, with an epothilone B to A ratio of 127 to 1, which was 100 times higher than that of the wild-type cells, demonstrating its potential use for the selective production of epothilone B.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1416-1422
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• 2008

Epothilone and its analogs are a potent new class of anticancer compounds produced by myxobacteria. Thus, in an effort to identify new myxobacterial strains producing epothilone and its analogs, cellulose-degrading myxobacteria were isolated from Korean soils, and 13 strains carrying epothilone biosynthetic gene homologs were screened using a polymerase chain reaction. A migration assay revealed that Sorangium cellulosum KYC3013, 3016, 3017, and 3018 all produced microtubule-stabilizing compounds, and an LC-MS/MS analysis showed that S. cellulosum KYC3013 synthesized epothilone A.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1653-1659
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• 2015

Epothilone, which is produced by the myxobacterium Sorangium cellulosum, contributes significant value in medicinal development. However, under submerged culture conditions, S. cellulosum will accumulate to form bacterial clumps, which hinder nutrient and metabolite transportation. Therefore, the production of epothilone by liquid fermentation is limited. In this study, diatomite-based porous ceramics were made from diatomite, paraffin, and poremaking agent (saw dust). Appropriate methods to modify the porous ceramics were also identified. After optimizing the preparation and modification conditions, we determined the optimal prescription to prepare high-performance porous ceramics. The structure of porous ceramics can provide a solid surface area where S. cellulosum can grow and metabolize to prevent the formation of bacterial clumps. S. cellulosum cells that do not form clumps will change their erratic metabolic behavior under submerged culture conditions. As a result, the unstable production of epothilone by this strain can be changed in the fermentation process, and the purpose of increasing epothilone production can be achieved. After 8 days of fermentation under optimized conditions, the epothilone yield reached 90.2 mg/l, which was increased four times compared with the fermentation without porous ceramics.

• 미생물학회지
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• 제47권2호
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• pp.170-173
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• 2011

국내에서 분리된 에포틸론 생산 점액세균 Sorangium cellulosum KYC3013의 에포틸론 생합성 유전자군(epoA~F, epoK)을 클로닝하였다. 이 유전자들이 암호화하고 있는 단백질들의 아미노산 서열을 다른 대륙 또는 나라에서 분리된 S. cellulosum SMP44, S. cellulosum So ce90, S. cellulosum So0157-2의 단백질들과 비교한 결과 서로 97.4-99.8% 동일하였다. 이러한 결과는 에포틸론 생합성 유전자들이 S. cellulosum 균주들 사이에서 잘 보존되어 있음을 보여주었다.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1208-1212
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• 2007

Production of extracellular epothilone B, one of the potent anticancer agents, by free and immobilized Sorangium cellulosum was studied using the repeated batch culture process. The concentration of alginate used in immobilization was directly related to the mass transfer rate of nutrients, mechanical stability, and the epothilone B production yield. With the optimized 3% (w/v) calcium alginate carrier, a prolonged repeated batch culture was investigated for the 5 repeated batches for 24 days. The maximum productivity of epothilone B obtained from the alginate-immobilized cells was 5.03 mg/l/day, which is 3 times higher than that of free cells (1.68 mg/l/day).

• Journal of Microbiology and Biotechnology
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• 제16권4호
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• pp.519-523
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• 2006

To improve epothilones production and the ratio of epothilone B/A, carbon sources were investigated in flask culture of Sorangium cellulosum. Depending on the initial concentration, starch significantly enhanced cell growth, but the maximum epothilones productivity and the maximum epothilones production (0.3 mg/l day and 2.6 mg/l at 15 g/l starch, respectively) were relatively low compared with cell growth. On the other hand, addition of glycerol did not stimulate cell growth, but epothilone production was increased from 2.81 mg/l to 7.59 mg/l. Addition of glycerol to culture medium resulted in more significant enhancement of the production of epothilone A, whereas epothilone B levels were relatively constant. Furthermore, when sodium propionate was added as a precursor of methylmalonyl-CoA, it resulted in increase of both total epothilones production and epothilone B/A resolution. Maximum epothilone A and B concentrations reached 10.9 mg/l and 8.58 mg/l, respectively, at 5 mM sodium propionate.

• 식물병연구
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• 제24권3호
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• pp.213-220
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• 2018

섬유소 분해 점액세균인 Sorangium cellulosum 균주들 중 Botrytis cinerea에 길항력을 갖는다고 보고한 4균주(Antagonistic to Botrytis, AB 계열)와 Colletotrichum acutatum에 길항력을 갖는다고 보고한 2균주(Antagonistic to Colletotrichum, AC 계열)를 5가지(A-E)의 S. cellulosum 아종(subspecies)으로 분류하였다. 분류 기준 유전자인 xynB1, bglA2, groEL1 세 유전자의 유전자 유무 및 염기서열 분석을 통해 AB 계열은 아종 C, AC 계열은 아종 D로 분류하였다. 또한, 배양추출물을 고효율 액체크로마토그래피(HPLC)로 분석한 아종 분류 결과 AB 계열 4균주는 머무름시간 20-22.5분에 유사한 특징 피크가 나타난 반면, AC 계열인 2균주는 특징 피크가 없으므로 AB 계열은 아종 C, AC 계열은 아종 D임을 재확인하였다. AB 계열 4균주들의 배양여액을 사용하여 방울토마토에 전처리 후 B. cinerea를 접종한 생물검정으로 방제가와 크로마토그램 특징 피크의 상대 면적값과의 상관분석 결과, 피크 면적이 큰 균주일수록 방제가도 높은 양의 상관관계($R^2=0.9652$)를 확인하였다. 아종 분류 결과 AB 계열은 아종 C의 대표 생리활성 물질의 파생물인 epothilone D로 추정되어, 이를 표준시료로 HPLC 분석한 결과 epothilone D의 머무름시간은 9.9분이었던 반면, KYC 3270 특성 피크의 머무름시간은 11.581분으로 달랐다. 따라서 우리는 AB 계열이 분비하는 생리활성 물질은 epothilone의 파생물인 7-ketone epothilone D로 추정하였다.

• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.1972-1984
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• 2013

Microtubules play an important role in intracellular transport, mobility, and particularly mitosis. Paclitaxel (Taxol$^{TM}$) and paclitaxel-like compounds have been shown to be anti-tumor agents useful for various human tumors. Paclitaxel-like compounds operate by stabilizing microtubules through interface binding at the interface between two ${\beta}$-tubulin monomers in adjacent protofilaments. In this paper we present the elucidation of the structural features of paclitaxel and paclitaxel-like compounds (e.g., epothilones) with microtubule stabilizing activities, and relate their activities to spatial and chemical features of the molecules. CATALYST program was used to generate three-dimensional quantitative structure activity relationships (3D-QSARs) resulting in 3D pharmacophore models of epothilone- and paclitaxel-derivatives. Pharmacophore models were generated from diverse conformers of these compounds resulting in a high correlation between experimental and predicted biological activities (r = 0.83 and 0.91 for epothilone and paclitaxel derivatives, respectively). On the basis of biological activities of the training sets, five- and four-feature pharmacophore hypotheses were generated in the epothilone and paclitaxel series. The validation of generated hypotheses was achieved by using twelve epothilones and ten paclitaxels, respectively, which are not in the training sets. The clustering (grouping) and merging techniques were used in order to supplement spatial restrictions of each of hypothesis and to develop more comprehensive models. This approach may be of use in developing novel inhibitor candidates as well as contributing a better understanding of structural characters of many compounds useful as anticancer agents targeting microtubules.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6535-6539
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• 2015

This study was designed to assess, whether a new chemotherapeutic microtubule inhibitor, Epothilone B (EpoB, Patupilone), can induce DNA damage in normal ovarian cells (MM14.Ov), and to evaluate if such damage could be repaired. The changes were compared with the effect of paclitaxel (PTX) commonly employed in the clinic. The alkaline comet assay technique and TUNEL assay were used. The kinetics of DNA damage formation and the level of apoptotic cells were determined after treatment with IC50 concentrations of EpoB and PTX. It was observed that PTX generated significantly higher apoptotic and genotoxic changes than EpoB. The peak was observed after 48 h of treatment when the DNA damage had a maximal level. The DNA damage induced by both tested drugs was almost completely repaired. As EpoB in normal cells causes less damage to DNA it might be a promising anticancer drug with potential for the treatment of ovarian tumors.