SINGLET OXYGEN AND PEROXYL RADICALS REGULATE CAROTENOID BIOSYNTHESIS IN PHAFFIA-RHODOZYMA
SINGLET OXYGEN AND PEROXYL RADICALS REGULATE CAROTENOID BIOSYNTHESIS IN PHAFFIA-RHODOZYMA
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DOI：
10.1074/jbc.270.31.18374
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发表时间：
1995-08-04
影响因子：
4.8
通讯作者：
JOHNSON, EA
中科院分区：
文献类型：
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作者：
SCHROEDER, WA;JOHNSON, EA
类胡萝卜素最近受到了相当大的关注，因为它们在延缓或预防诸如动脉硬化、癌症和衰老等退行性疾病方面具有潜力。在本研究中，我们发现活性氧单重态氧(O-1(2))和过氧基对红发夫酵母中类胡萝卜素的组成和生物合成有不同的影响。(1)0(2)与孟加拉玫瑰或α-三茂铁光化学生成诱导类胡萝卜素积累。相反，过氧化氢或过氧化氢产生的过氧基降低了虾青素的含量，增加了约4倍的β-胡萝卜素，提示了虾青素或抑制生物合成酶对最终产物的反馈调节，氧化胁迫过程中类胡萝卜素的C-14标记支持了最终产物调节的可能性。当百里香酚抑制类胡萝卜素的生成时，类胡萝卜素在6h内被8 mM的tBOOH漂白。经过氧化氢处理后，红发酵母菌中产生了一种以前未见报道的色素，其类胡萝卜素的质量为580Da，分子式为C40H5203。化学衍生化结合质量和吸收光谱初步鉴定为脱氢软黄质(3，1‘-二羟基2，3，3’，4‘-四氢-1’，2‘-二氢-β-二氢，psi-胡萝卜素-4-酮)。本研究首次报道了(1)0(2)在红发夫酵母中诱导虾青素的生物合成，虾青素可能的反馈控制，以及虾青素的氧化降解为新的色素。
Carotenoids have recently received considerable interest because of their potential in delaying or preventing degenerative diseases such as arteriosclerosis, cancer, and aging. In this study we show that the active oxygen species singlet oxygen (O-1(2)) and peroxyl radicals differently affect carotenoid composition and biosynthesis in the yeast Phaffia rhodozyma. Photochemical generation of (1)0(2) with rose bengal or alpha-terthienyl induced carotenoid accumulation. In contrast, peroxyl radicals derived from t-butylhydroperoxide (tBOOH) or H2O2 decreased the content of astaxanthin and increased beta-carotene by similar to 4-fold, suggesting end product feedback regulation by astaxanthin or inhibition of bio synthetic enzymes, C-14 labeling of carotenoids during oxidative stress supported the possibility of end product regulation. Carotenoids were bleached by 8 mM tBOOH within 6 h when carotenogenesis was inhibited by thymol. When treated with peroxides, a previously unreported pigment in P. rhodozyma was formed, The carotenoid had a mass of 580 Da and a molecular formula of C40H52O3. Chemical derivatizations combined with mass and absorbance spectroscopy tentatively identified the carotenoid as dehydroflexixanthin (3,1'-dihydroxy2,3,3 ',4'-tetradehydro 1',2'-dihydro beta,psi-carotene-4-one). This study provides the first report of induction of astaxanthin biosynthesis by (1)0(2), probable feedback control by astaxanthin, and the oxidative degradation of astaxanthin to novel pigments in P. rhodozyma.