• Applied Biological Chemistry
• /
• 제41권1호
• /
• pp.47-52
• /
• 1998

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) 환원효소는 식물의 병원균 방어물질 (phytoalexin), 광합성 색소 (the phytol of chlorophyll), 성장 호르몬 (abscisic acid와 gibberellin 등) 및 스테롤 (phytosterol) 등의 생합성에 관여하는 주효소이다. 암조건 하에서 발아 후 4일째의 벼 유묘 microsome을 재료로 비이온성 detergent 인 Brij W-1 (final 0.4%)을 사용하여 가용화 시킨 후, DEAE-Sephadex A-50 크로마토그래피 칼럼과 hexaneagarose를 matrix로 기질인 HMG-CoA를 결합시켜 제조한 친화성 크로마토그래피 칼럼을 이용하여 세포막 결합효소인 HMG-CoA 환원효소를 정제하였다. 정제된 HMG-CoA 환원효소의 최종 회수율은 7.14% 였고, 분자량은 10% SDS-PAGE에서 55 kDa이였다 HMG-CoA 환원효소의 최적 반응 온도는 $37^{\circ}C$, 최적 반응 pH는 6.9였고, 기질인 HMG- CoA에 대한 HMG-CoA 환원효소의 $K_m$ 및 $V_{max}$ 값은 $180\;{\mu}M$과 107 pmol/mg, 수소공여체인 NADPH에 대한 $K_m$과 $V_{max}$값은 $810\;{\mu}M$과 32.1 pmol/min/mg이였다.

• Mycobiology
• /
• 제50권2호
• /
• pp.121-131
• /
• 2022

The rare edible and medicinal fungus Antrodia cinnamomea has a substantial potential for development. In this study, Illumina HiSeq 2000 was used to sequence its transcriptome. The results were assembled de novo, and 66,589 unigenes with an N50 of 4413 bp were obtained. Compared with public databases, 6,061, 3,257, and 2,807 unigenes were annotated to the Non-Redundant, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes databases, respectively. The genes related to terpene biosynthesis in the mycelia of A. cinnamomea were analyzed, and acetyl CoA synthase (ACS2 and ACS4), hydroxymethylglutaryl CoA reductase (HMGR), farnesyl transferase (FTase), and squalene synthase (SQS) were found to be upregulated in XZJ (twig of C. camphora) and NZJ (twig of C. kanehirae). Moreover, ACS5 and 2,3-oxidized squalene cyclase (OCS) were highly expressed in NZJ, while heme IX farnesyl transferase (IX-FIT) and ACS3 were significantly expressed in XZJ. The differential expression of ACS1, ACS2, HMGR, IX-FIT, SQS, and OCS was confirmed by real-time quantitative reverse transcription PCR. This study provides a new concept for the additional exploration of the molecular regulatory mechanism of terpenoid biosynthesis and data for the biotechnology of terpenoid production.

• BMB Reports
• /
• 제46권4호
• /
• pp.207-212
• /
• 2013

The main purpose of this study is to examine the effect of caffeine on lipid accumulation in human hepatoma HepG2 cells. Significant decreases in the accumulation of hepatic lipids, such as triglyceride (TG), and cholesterol were observed when HepG2 cells were treated with caffeine as indicated. Caffeine decreased the mRNA level of lipogenesis-associated genes (SREBP1c, SREBP2, FAS, SCD1, HMGR and LDLR). In contrast, mRNA level of CD36, which is responsible for lipid uptake and catabolism, was increased. Next, the effect of caffeine on AMP-activated protein kinase (AMPK) signaling pathway was examined. Phosphorylation of AMPK and acetyl-CoA carboxylase were evidently increased when the cells were treated with caffeine as indicated for 24 h. These effects were all reversed in the presence of compound C, an AMPK inhibitor. In summary, these data indicate that caffeine effectively depleted TG and cholesterol levels by inhibition of lipogenesis and stimulation of lipolysis through modulating AMPK-SREBP signaling pathways.

• Molecules and Cells
• /
• 제22권3호
• /
• pp.269-274
• /
• 2006

In order to characterize saikosaponin biosynthesis in Bupleurum falcatum, the expression of five isoprenoid pathway genes and their relationship to saikosaponin accumulation in the hairy roots were analyzed. The hairy roots exhibited a rapid accumulation of saikosaponins when incubated in a root culture medium (3XRCM). Homology-based RT-PCR was used to isolate core fragments of five genes, HMGR, IPPI, FPS, SS, and OSC, from the hairy roots. The deduced amino acid sequences exhibited amino acid identities of more than 85% to previously reported genes. Using the fragments as probes, the expression of these five genes in the hairy roots during incubation in 3XRCM medium was examined. Expression of all five genes in the hairy roots increased soon after incubation. In particular, the SS and OSC genes were coordinately induced at 8 days of incubation, and their expression persisted throughout the incubation period. A quantitative HPLC analysis showed that the saikosaponin content of the hairy root culture also began to increase at 8 days of culture. The correlation between SS transcript level and saikosaponin content in the hairy roots suggests that transcriptional regulation plays a regulatory role in saikosaponin biosynthesis.