• 생명과학회지
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• 제18권2호
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• pp.273-278
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• 2008

콜레스테롤 생합성 과정에 있어서 속도조절 단계 효소의 하나인 squalene synthase에 대한 저해물질의 탐색을 목적으로, 30종의 다양한 천연물을 대상으로 squalene synthase에 대해 저해효과를 검토한 결과 녹차추출물에서 비교적 저해활성이 높고 재현성이 있게 저해효과를 나타내는 것으로 확인되었다. 녹차에 함유되어 있는 squalene synaase에 대한 저해물질의 용매추출성을 검토한 결과 ethyl acetate와 n-butanol 층에 저해물질이 많이 함유되어 있는 것으로 확인되었으며 저해물질은 녹차의 polyphenol 화합물인 catechin에 의한 것으로 추정되었다. Catechin 표준용액의 각 농도에 따른 squalene synthase 저해작용을 살펴 본 결과, (-)-epigallocatechin gallate, (-)-epicatechin gallate, (-)-epigauocatechin, (-)-epicatechin, (+)-catechin의 순으로 저해활성이 강한 것으로 나타났으며 가장 강한 저해활성을 나타내는 (-)-epigallocatechin gallate의 $IC_{50}$값은 $90{\mu}M$이었다.

• 한국식품과학회지
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• 제35권2호
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• pp.297-301
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• 2003

동맥경화증과 같은 심혈관 질환을 야기시키는 주요 위험요인인 혈중 콜레스테롤의 수준을 낮추기 위하여 콜레스테롤 생합성 과정의 속도조절단계 효소의 하나인 squalene synthase의 활성을 저해하는 물질을 분리 정제하여, 물질의 이화학적 특성과 생물학적 특성을 검토하였다. Squalene synthase 저해물질은 acetone extraction, ethyl acetate extraction, silica gel column chromatography, sephadex LH-20 column chromatography, 결정화 등을 이용하여 분리 정제하여 YUF-01을 얻었다. 기기분석을 통하여 구조분석을 행한 결과 YUF-01은 분자량 368, 분자식 $C_{20}H_{21}O_6$으로 분석되었으며 243과 421 nm 에서 UV-VIS 흡광을 나타내었고 $^{13}C$ NMR spectrum과 $^1H$ NMR spectrum을 검토하였을 때 aromatic ketone 구조인 curcuminoid 계통의 curcumin과 일치하였다. Squalene synthase에 대한 curcumin의 $IC_{50}$ 값은 $100{\mu}M$이었으며, non-competitive inhibitor로 작용하였다.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.222-227
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• 2002

Squalene synthase catalyzes the reductive dimerization of two molecules of farnesyl diphosphate to form squalene at the final branch point of the cholesterol biosynthetic pathway. Due to the unique position of this enzyme in the pathway, its inhibitors may have advantages as antihypercholesterolemic agents. Therefore, selective inhibitors of squalene synthase do not prevent the formation of the essential branch products of the isoprene pathway, such as dolichol, coenzyme-Q, and prenylated proteins, as might be expected for inhibitors of enzymes earlier in the pathway; for example, lovastatin and mevalotin. The current study reports that CJ90002, a pentagalloylglucose isolated from Paeonia moutan SIM (Paeoniaceae), which is an important Chinese crude drug used in many traditional prescriptions, was a potent inhibitor of rat microsomal squalene synthase, and also a potent inhibitor of cholesterol biosynthesis in vitro. In addition, the intraperitoneal and oral administration of CJ90002 had a significant lowering effect on plasma cholesterol levels in hamsters.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1970-1975
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• 2007

Squalene synthase plays an important role in the cholesterol biosynthetic pathway. Inhibiting this enzyme in hypercholesterolemia can lower not only plasma cholesterol but also plasma triglyceride levels. A squalene synthase inhibitor was screened from Prunus mume fruit, and then purified via sequential processes of ethanol extraction, HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, and crystallization. The squalene synthase inhibitor was identified as chlorogenic acid with a molecular mass of 354 Da and a molecular formula of $C_{16}H_{18}O_9$ based on UV spectrophotometry, $^1H$ and $^{13}C$ NMRs, and mass spectrometry. Chlorogenic acid inhibited the squalene synthase of pig liver with an $IC_{50}$ level of 100 nM. Since chlorogenic acid was an effective inhibitor against the squalene synthase of an animal source, it may be a potential therapeutic agent for hypercholesterolemia.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1106-1112
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• 2007

This report provides the complete nucleotide sequences of the full-length cDNA encoding squalene synthase (SQS) and its genomic DNA sequence from a triterpene-producing fungus, Ganoderma lucidum. The cDNA of the squalene synthase (SQS) (GenBank Accession Number: DQ494674) was found to contain an open reading frame (ORF) of 1,404 bp encoding a 468-amino-acid polypeptide, whereas the SQS genomic DNA sequence (GenBank Accession Number: DQ494675) consisted of 1,984 bp and contained four exons and three introns. Only one gene copy was present in the G. lucidum genome. The deduced amino acid sequence of Ganoderma lucidum squalene synthase (GI-SQS) exhibited a high homology with other fungal squalene synthase genes and contained six conserved domains. A phylogenetic analysis revealed that G. lucidum SQS belonged to the fungi SQS group, and was more closely related to the SQS of U. maydis than to those of other fungi. A gene expression analysis showed that the expression level was relatively low in mycelia incubated for 12 days, increased after 14 to 20 days of incubation, and reached a relatively high level in the mushroom primordia. Functional complementation of GI-SQS in a SQS-deficient strain of Saccharomyces cerevisiae confirmed that the cloned cDNA encoded a squalene synthase.

• Journal of the Korean Wood Science and Technology
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• 제32권1호
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• pp.17-27
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• 2004

식용 임산자원인 산채류를 기능성 식품으로 개발하고자 산마늘을 비롯한 총 13종의 에탄올 조추출물에 대한 콜레스테롤 저하활성을 검정하였다. 즉, 콜레스테롤 생합성 과정 초기에 관여하는 3-hydroxy-3-methylglutaryl coenzyme A reductase(HMG-CoA reductase)와 후기에 관여하는 squalene synthase의 효소 활성을 조사한 결과 산마늘 잎 에탄올 추출물이 두 효소의 활성을 공히 70% 이상 저해하여 활성이 가장 우수한 것으로 나타났다. 그리고 이러한 콜레스테롤 저하활성과 관련이 있는 물질을 탐색하고자 산마늘로부터 물질 단리를 시도하여 디클로로메탄 가용부로부터 kaempferol과 quercetin을 단리하였다. 또한 유전자 레벨에서의 콜레스테롤 저하 활성을 조사하기 위해 단리물질과 분획물을 C100세포(햄스터 유래 HMG-CoA reductase 고발현 세포주)에 각각 5 ㎍/㎖과 10 ㎍/㎖로 24시간 처리하여 HMG-CoA reductase와 squalene synthase의 mRNA 발현 정도를 조사하였다. 그 결과 10 ㎍/㎖로 kaempferol과 quercetin을 처리한 경우 두 효소의 mRNA가 전혀 발현하지 않는 것으로 나타나 유전자 레벨에서의 콜레스테롤 생합성 저해 효과를 확인할 수 있었다. 이상의 결과 산마늘 잎 에탄올 추출물은 콜레스테롤 생합성에 관여하는 HMG-CoA reductase와 squalene synthase의 활성을 저해하며 이러한 활성 저해 효과는 kaempferol과 quercetin에 기인하는 것으로 사료되었다. 특히 kaempferol과 quercetin은 여러 식물의 성분으로서 이미 알려진 화합물이지만 콜레스테롤 저하활성이 있는 것으로 밝혀진 것은 이번이 처음으로 금후 이들 물질과 이들 물질을 함유하고 있는 식물 활용에 필요한 자료를 제공하였다고 사료된다.

• Food Science and Biotechnology
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• 제14권1호
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• pp.89-93
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• 2005

Squalene synthase (SQS) inhibitors were screened from various plants and food extracts. Effective SQS inhibitor was purified from fermented soybean paste using ethanol extraction, HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, and crystallization. Through UV spectrometry, $^1H$ NMR, $^{13}C$ NMR, and mass spectrometry, SQS inhibitor was identified as daidzein with molecular mass of 254 and molecular formula of $C_{15}H_{10}O_4$. Daidzein showed $IC_{50}$ value of 50 nmol/L against SQS, confirming its potential as therapeutic agent for hypercholesterolemia.

• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.441-451
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• 2016

Squalene is a linear triterpene formed via the MVA or MEP biosynthetic pathway and is widely distributed in bacteria, fungi, algae, plants, and animals. Metabolically, squalene is used not only as a precursor in the synthesis of complex secondary metabolites such as sterols, hormones, and vitamins, but also as a carbon source in aerobic and anaerobic fermentation in microorganisms. Owing to the increasing roles of squalene as an antioxidant, anticancer, and anti-inflammatory agent, the demand for this chemical is highly urgent. As a result, with the exception of traditional methods of the isolation of squalene from animals (shark liver oil) and plants, biotechnological methods using microorganisms as producers have afforded increased yield and productivity, but a reduction in progress. In this paper, we first review the biosynthetic routes of squalene and its typical derivatives, particularly the squalene synthase route. Second, typical biotechnological methods for the enhanced production of squalene using microbial cell factories are summarized and classified. Finally, the outline and discussion of the novel trend in the production of squalene with several updated events to 2015 are presented.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.116-120
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• 2004

The medicinal properties of Ganoderma lucidum have been recognized in China for many centuries. Active pharmaceutical components include triterpenes. To elucidate the molecular regulation of triterpene biosynthesis in this mushroom, a 57-base pair DNA fragment encoding the fourth conserved domain SQ-4 (SMGLFLQKTNIIRDYNEDL) of squalene synthase was synthesized and cloned into the expression vector pET-32a(＋). The recombinant fusion protein induced by IPTG (isopropyl-$\beta$-D-thiogalactopyranoside) was overexpressed in the Escherichia coli. Using the purified recombinant fusion protein of 20.9 kDa, a specific polyclonal antibody was obtained from immunized rabbit. Expression of squalene synthase at different development stages of Ganoderma lucidum was analyzed.

• Journal of Ginseng Research
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• 제34권2호
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• pp.98-103
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• 2010

The medicinal plant Panax ginseng (P. ginseng) contains various phytosterols and bioactive triterpene saponins (ginsenosides). Squalene synthase catalyzes the first committed step in ginsenoside biosynthesis. Transgenic plants of P. ginseng were generated by introducing the squalene synthase gene derived from P. ginseng. Adventitious roots of the transgenic ginseng grew best in B5 medium, and 2 g of inoculum secured an optimal growth rate. Two phytohormones, indolebutyric acid and 1-naphtalene acetic acid, increased root growth and decreased ginsenoside production. Treatment with two selected elicitors, chitosan and jasmonic acid, and a precursor of the isoprenoid pathway, mevalonic acid, enhanced ginsenoside production and retarded ginseng growth rate.