강낭콩 현탁배양세포에서 추출된 Enzyme Pool의 C27 Brassinosteroids 합성능력
Ability for Biosynthesis of C27 Brassinosteroids by an Enzyme Pool Prepared from Cultured Cells of Phaseolus vulgaris
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초록
강낭콩 현탁 배양세포로부터 얻어진 효소원을 이용한 효소 변환 실험을 통하여 동 세포내에 cholesterol → cholestanol과 6-deoxo-28-norteasterone ↔ 6-deoxo-28-nor-3- dehydroteasterone ↔ 6-deoxo-28-nortyphasterol → 6-deoxo- 28-norcastasterone → 28-norcastasterone의 생합성과정이 존재함을 확인하였다. 이 결과는 비록 cholestanol에서 6- deoxo-28-norcathasterone을 경유하여 6-deoxo-28-norteasterone로의 변환은 확인하지 못하였지만 동 세포에는 cholesterol에서부터 6-deoxo-28-nor형 brassinosteroids를 경유하여 28-norcastasterone을 생합성하는 모든 효소들이 포함되어 있음을 시사하는 것으로서, 동 세포에는 상기의 생합성과정, 즉 C27 brassinosteroids의 the late C-6 oxidation 과 정이 작용하고 있음을 나타내는 결과라 하겠다. 또한 얻어진 효소원은 S-adenosyl-methionine과 NADPH의 존재 하에 28-norcastasterone을 castasterone으로 변환시켜, 강낭콩 세포내의 C28 활성형 brassinosteroid인 castasterone의 생합성에 C27 brassinosteroids 생합성과정이 중요한 경로중 하나임을 알 수 있었다. 이러한 결과들은 이미 본 연구실에서 밝힌 토마토에 있어 C27 brassinosteroids 생합성과정이 토마토의 활성형 brassinosteroid인 castasterone의 함량조절에 관여한다는 결과와 함께 토마토 이외의 식물들에 있어서도 C27 brassinosteroids 생합성에 의한 활성형 C28 brassinosteroid(s)의 함량조절에 일어나고 있음을 처음으로 밝힌 중요한 결과라 하겠다.
Abstract
A cell-free enzyme solution prepared from suspension cultured cells of Phaseolus vulgaris successfully mediated conversions of cholesterol cholestanol and 6-deoxo-28-norteasterone 6-deoxo-28-nor- 3-dehydroteasterone 6-deoxo-28-nortyphasterol 6-deoxo-28-norcastasterone 28-norcastasterone. Although conversion of cholestanol to 6-deoxo-28-norteasterone intermediated by 6-deoxo-28-norcathasterone was not demonstrated, this strongly suggests that a complete set of biosynthetic enzymes catalyzing reactions from cholesterol to 28-norcastasterone via 6-deoxo-28-nor type brassinosteroids is endogenously present in the cells, which demonstrates that a C27 brassinosteroids biosynthetic pathway, namely the late C-6 oxidation for C27 brassinosteroids, is operative in the cells. Additionally, the enzyme solution mediated conversion of 28- norcastasterone to castasterone in the presence of S-adenosyl-methionine and NADPH, providing that the C27 brassinosteroids biosynthesis is an important route to generate castasterone in the cells. Together with our previous finding that castasterone can be biosynthesized by the same biosynthetic pathway in tomato, this study demonstrates that the C27 brassinosteroids biosynthesis is a common alternative process to maintain endogenous level of castasterone, an active C28 brassinosteroid, in plants.
참고문헌 (15)
- Bajguz A, "The chemical characteristic and distribution of brassinosteroids in plants", 62, pp.1027~1046 (2003)
- Bishop GJ, "Current Highlights of Molecular Aspects on their Synthesis", Metabolism, 2001, pp.42, 114~120
- Bradford MM, "A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding", pp.248~254 (1976)
- Clouse SD, "Brassinosteroids", pp.1~25 (2002)
- Diener AC, "Sterol methyltransferase 1 controls the level of cholesterol in plants", 12, pp.853~870 (2000)
- Fujioka S, "Natural Occurrence of Brassinosteroids in the Plant Kingdom", brassi(steroids), pp.21~45 (1999), Springer-Verlag
- Kelly SL, "Purification and reconstitution of activity of Saccharomyces cerevisiae P450 61", 377, pp.217~220 (1995)
- Kim TW, "Novel biosynthetic pathway of castasterone from cholesterol in tomato", 135, pp.1231~42 (2004)
- Nakajima N, "Biosynthesis of cholestanol in higher plants", 60, pp.275~279 (2002)
- Sakurai A, "Physiological Actions of Brassinosteroids", pp.137~161 (1999), Springer-Verlag
- Shi J, "Identification and characterization of an S-adenosyl-L-methionine 24 -sterol-C-methyltransferase cDNA from soybean", 271, pp.9384~9389 (1996)
- Yokota T, "biosynthesis and function of brassinosteroids", 2, pp.137~143 (1997)
- Yokota T, "Biochemistry and molecular biology of plants", brassi(steroids), pp.901~911 (2000)
- Yokota T, "Identification of brassinosteroids that appear to be derived from campestrol and cholesterol in tomato shoots", 38, pp.1291~1294 (1997)
- Yokota T, "Roots and shoots of tomato produce 6-deoxo-28-norcathasterone possible precursors of 28-norcastasterone", 58, pp.233~238 (2001)