• 한국미생물·생명공학회지
• /
• 제38권4호
• /
• pp.475-480
• /
• 2010

Actinomycetes are Gram-positive soil bacteria and one of the most important industrial microorganisms due to superior biosynthetic capabilities of many valuable secondary metabolites as well as production of various valuable bioconversion enzymes. Among them are cytochrome P450 hydroxylase (CYP), which are hemoproteins encoded by a super family of genes, are universally distributed in most of the organisms from all biological kingdoms. Actinomycetes are a rich source of soluble CYP enzymes, which play critical roles in the bioactivation and detoxification of a wide variety of metabolite biosynthesis and xenobiotic transformation. Cyclosporin A (CyA), one of the most commonly-prescribed immunosuppressive drugs, was previously reported to be hydroxylated at the position of 4th N-methyl leucine by a rare actinomycetes called Sebekia benihana, leading to display different biological activity spectrum such as loss of immunosuppressive activities yet retaining hair growth-stimulating side effect. In order to improve this regio-selective CyA hydroxylation in S. benihana, previously-identified several secondary metabolite up-regulatory genes from Streptomyces coelicolor and S. avermitilis were heterologously overexpressed in S. benihana using an $ermE^*$ promoter-containing Streptomyces integrative expression vector. Among tested, SCO4967 encoding a conserved hypothetical protein significantly stimulated region-specific CyA hydroxylation in S. benihana, implying that some common regulatory systems functioning in both biosynthesis and bioconversion of secondary metabolite might be present in different actinomycetes species.

• 한국미생물·생명공학회지
• /
• 제13권1호
• /
• pp.19-25
• /
• 1985

Saccharomyces cerevisiae HIS 5 유전자는 histidinol phosphate aminotransferase (EC: 2, 6, 1,9)를 code하는 아미노산 합성유전자이다. 이 유전자는 plasmid pSH 530에 cloning되어 E. coli와 Saccharomyces cerevisiae 숙주에서 promoter로서 전사하였다. HIS 5 유전자의 총염기 수는 736개이였고 5' 상류영역에는 긴 reading frame, directed repeat, 전사개시점, 그리고 Pribnow box염기배열이 있었다. 특히 HIS 5 유전자의 ATG 주변 염기배열은 -A-A-A-T-T-A-C-A-C-T-A-T-G-G-T-T-T-T-T-G-A-T-였으며 C block은 없었다.

• Journal of Applied Biological Chemistry
• /
• 제54권4호
• /
• pp.244-251
• /
• 2011

Galactinol and rafinose accumulation in plants is associated with stressful environmental conditions such as cold, heat, or dehydration by the action of galactinols synthase (GolS) in the raffinose family of oligosaccharides biosynthetic pathway from UDP-galactose. Moreover, several reports mentioned that GolS transcription is up regulated by various environmental stresses like cold, heat, dehydration. Therefore, to determine whether MoGolS1 was induced with the abiotic stress we analyzed the expression pattern of the gene under various abiotic stresses like heat, cold, abscisic acid, sucrose and salt concentration in the lemon balm plants grown in standard MS medium. The MoGolS1 gene was 981-bp in length encoding 326 amino acids in its sequence and shared 77 and 76% sequence similarity with Arabidopsis thaliana galactinol synthase4 (AtGolS4) and AtGolS1 genes respectively. The MoGolS1 gene was strongly expressed by the abiotic stress induced by sucrose, ABA or heat shock. It was also expressed in responses to cold, Identification and Functional Characterization of the GALACTINOL SYNTHASgene induction with various stresses may be possible for itscrucial function in abiotic stress tolerance in plants, providing a good engineering target for genetic engineering.

• 대한화장품학회:학술대회논문집
• /
• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
• /
• pp.192-202
• /
• 2003

The wrinkles correspond to the most obvious expression of skin ageing and are manifested by changes on the organization and dermal structure. In the extracellular matrix, decreased quantities of collagens and glycosaminoglycans as well as a deterioration of the fibrillary network is noted, result in a reduction of dermal thickness. In addition, the activity of the collagenases increases in contrast to the synthesis of collagen fibers. Nor are cells spared during the aging process. We thus studied and compared the contractile capacity as well as the synthesis capacity of normal human fibroblasts and human fibroblasts obtained from biopsies of forehead wrinkles. The capacity of the fibroblasts to be adhered to the collagen network and to maintain a three-dimensional structure of dermis was studied on a model of equivalent dermis. The metabolic activity was studied by evaluating the capacities of synthesis of collagen I, main component of dermis. Human fibroblasts resulting from the forehead wrinkle contract less the gel of collagen than the normal human fibroblasts and present an activity of biosynthesis of collagen I less important than normal human fibroblasts. These results show that fibroblasts with aging present a deceleration of their metabolic activity and lose their capacity of adhesion to collagen fibers thus limiting the possibility of organizing the dermal tissue. We investigated the potential of an active ingredient able to compensate for the reduction of the metabolic activity and to restore the contractile capacity of fibroblasts obtained from forehead wrinkles. This effect was compared with a reference molecule: the vitamin C.

• 원예과학기술지
• /
• 제30권2호
• /
• pp.107-122
• /
• 2012

식물에서 화색은 종자를 퍼트리기 위해 꽃가루 매개충과 초식동물을 유인하는데 매우 중요한 도구이다. 사람에게 화색은 다채로운 시각적 다양성으로 큰 심미적 가치를 지님으로써 화훼산업의 발전은 새롭고 다양한 매력을 지닌 화색을 생산하는 방향으로 꾸준히 발전되어 왔다. 카로티노이드 성분은 화색 중에서 적색, 홍색, 황색을 나타내는 천연색소로서 이러한 카로티노이드 생합성 경로는 생명공학 기술을 이용하여 화색을 변화시키려는 대사공학의 주된 대상으로 여겨져 왔다. 본 총설에서는 카로티노이드 생합성 대사관련 유전자 발현 조절에 의한 색소 표현형의 변화를 소개하고자 하며, 최근 카로티노이드의 생합성을 넘어 절단과 축적 조절이 화색 변경을 위한 대표적인 기작으로 보고됨에 따라 다양한 화색만큼이나 다양한 조절 기작에 대한 현재까지의 지식을 총 동원하여 원하는 화색을 지닌 인공적인 꽃(engineered flower)을 생산하기 위한 전략을 종합해서 제시하고자 하였다.

• 식물조직배양학회지
• /
• 제24권5호
• /
• pp.279-284
• /
• 1997

Hyoscyamus muticus의 phytoalexin으로 알려진 solavetivone, lubimin, rishitin 생합성에 결정적 역할을 담당하는 isoprenoid pathway의 첫 분지효소인 vetispiradiene synthase의 유도특성과 solavetivone, lubimin phytoalexin 생합성과의 관련성을 구명하기 위하여 H. muticus 현탁세포배양 및 모상근배양에 Rhizoctonia solani 추출액을 elicitor로 처리하였다. Elicitor을 처리하지 않은 현탁세포 및 모상근배양에서는 효소활성, 효소단백질 및 solavetivone, lubimin등이 전혀 검출되지 않았으나, elicitor을 처리한 세포에서는 효소활성이 급속히 유도되어 처리 12시간 후에 최고의 활성을 보였으며 그 후 점점 감소하였다. 효소활성의 정도는 면역반응을 이용하여 측정한 효소 단백질의 함량과 밀접한 상관관계를 보였으며, phytoalexin 총 함량은 모상근배양에서 2배이상 높았다. 특히 solavetivone 및 lubimin 생합성은 현탁 및 모상근배양에서 서로 다른 특이성을 보였는데, 현탁배양에서는 lubimin을, 모상근배양에서는 solavetivone을 선택적으로 다량 생산하였다.

• Journal of Plant Biotechnology
• /
• 제37권4호
• /
• pp.388-393
• /
• 2010

감자의 괴경에 비타민 A의 전구물질인 베타 카로텐 또는 항산화활성이 높으나 일반식물에서는 합성되지 않는 astaxanthin과 같은 케토형 카로티노이드의 집적을 위한 연구가 최근 활발하게 진행되고 있다. 현재까지의 연구 결과를 요약하여 보면 $\beta$-carotene의 함량이 $47\;{\mu}g/g$ dry weight으로 대조구에 비하여 3,600배 까지 증가한 결과가 보고되었다. 또한, 해양 미생물로부터 분리한 $\beta$-carotene ketolase 유전자를 도입한 감자의 괴경에서 astaxanthin 등의 케토형 카로티노이드의 함량이 최고 $14\;{\mu}g/g$ dry weight 까지 증가하여 감자의 색깔이 붉은 색으로 변하였다고 보고하였다. 따라서 본 논문에서는 이들 형질전환 감자의 생산을 위하여 도입한 유전자의 종류, 대사공학적 전략, 문제점 및 향후 연구 방향 등에 관하여 논하고자 하였다.

• BMB Reports
• /
• 제40권5호
• /
• pp.625-635
• /
• 2007

The enzyme squalene synthase (EC 2.5.1.21) catalyzes a reductive dimerization of two farnesyl diphosphate (FPP) molecules into squalene, a key precursor for the sterol and triterpene biosynthesis. A full-length cDNA encoding squalene synthase (designated as TcSqS) was isolated from Taxus cuspidata, a kind of important medicinal plants producing potent anti-cancer drug, taxol. The full-length cDNA of TcSqS was 1765 bp and contained a 1230 bp open reading frame (ORF) encoding a polypeptide of 409 amino acids. Bioinformatic analysis revealed that the deduced TcSqS protein had high similarity with other plant squalene synthases and a predicted crystal structure similar to other class I isoprenoid biosynthetic enzymes. Southern blot analysis revealed that there was one copy of TcSqS gene in the genome of T. cuspidata. Semi-quantitative RT-PCR analysis and northern blotting analysis showed that TcSqS expressed constitutively in all tested tissues, with the highest expression in roots. The promoter region of TcSqS was also isolated by genomic walking and analysis showed that several cis-acting elements were present in the promoter region. The results of treatment experiments by different signaling components including methyl-jasmonate, salicylic acid and gibberellin revealed that the TcSqS expression level of treated cells had a prominent diversity to that of control, which was consistent with the prediction results of TcSqS promoter region in the PlantCARE database.

• Journal of Applied Biological Chemistry
• /
• 제59권3호
• /
• pp.215-220
• /
• 2016

식물의 이차생장의 결과로 생산되는 바이오매스의 대부분은 식물의 이차세포벽에 축적된다. 식물의 이차세포벽은 크게 셀룰로스, 헤미셀룰로스, 리그닌이라는 3가지 물질로 구성되며 이들 중 페놀성 복합 화학 물질인 리그닌은 셀룰로스나 헤미셀룰로스와 달리 알코올 발효과정의 저해 물질로이다. 따라서, 식물의 이차세포벽 생합성의 과정을 조절함으로 전체 바이오매스의 생산량과 조성을 바이오 에너지 생산을 위해 최적 조건으로 조절함으로써 바이오 에탄올 생산을 최대화할 수 있을 것이다. 본 연구에서는 애기장대 유래 MYB7 유전자를 CaMV35S 프로모터 조절 하에서 과별현되게 한 식물체와 식물의 전사조절에서 하위 특정 유전자의 발현을 저해시키는 것으로 잘 알려진 SRDX 융합 단백질 즉, MYB7-SRDX 과발현체를 제작하여 그 특성을 조사하였다. 그 결과 MYB7 전사조절 인자가 리그닌의 생합성을 억제 조절한다는 결과를 관찰하였다. 이는 MYB7 전사조절인자를 이용하면 바이오 에탄올 발효과정에 저해 물질로 작용하는 리그닌을 경감시킬 수 있는 기초 자료로 사용할 수 있을 것이다.

• Journal of Applied Biological Chemistry
• /
• 제52권3호
• /
• pp.93-102
• /
• 2009

Polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have significantly beneficial effects on health in relation to cardiovascular, immune, and inflammatory conditions and they are involved in determining the biophysical properties of membranes as well as being precursors for signaling molecules. PUFA biosynthesis is catalyzed by sequential desaturation and fatty acyl elongation reactions. This aerobic biosynthetic pathway was thought to be taxonomically conserved, but an alternative anaerobic pathway for the biosynthesis of PUFA is now known to contain analogous polyketide synthases (PKS). Certain fish oil can be a rich source of PUFA although processed marine oil is generally undesirable as food ingredients because of the associated objectionable flavors that are difficult and cost-prohibitive to remove. Oil-seed plants contain only the 18-carbon polyunsaturated fatty acid alpha-linolenic acid, which is not converted in the human body to EPA and DHA. It is now possible to engineer common oilseeds which can produce EPA and DHA and this has been the focus of a number of academic and industrial research groups. Recent advances and future prospects in the production of EPA and DHA in oilseed crops are discussed here.