类胡萝卜素代谢途径中相关番茄红素环化酶的功能  

Functions of related lycopene cyclases in the metabolic pathway of carotenoids

作　　者：朱跃辉[1] 姜建国[1] 

机构地区：[1]华南理工大学食品与生物工程学院,广州510640

出　　处：《中国食品添加剂》2005年第5期40-43,共4页China Food Additives

基　　金：国家自然科学基金资助项目(20076020)

摘　　要：番茄红素环化是其生物合成途径中的一个关键分支点。自然界存在两类氨基酸序列不相关的番茄红素环化酶,其中单体型环化酶在成环的化学机理,底物特异性和活性,蛋白特征及氨基酸序列保守性等方面的存在相似性,包括G-细菌的番茄红素环化酶CrtY,蓝藻的CrtL,以及绿藻和植物的Lyc-B/E及相关的Ccs和Nsy。另一类异二聚体型番茄红素环化酶则存在于G+细菌,古生菌和真菌中,其催化机理和需要的辅因子尚待进一步证实。Cyclization of lycopene is a key branch point in the carotenoid biosynthetic pathway. There are two types of lycopene cyclases unrelated in their amino acid sequences in nature, one type of which is monomeric cyclase showing similaries in the chemical mechanism for formation of β-, ε-and k-ring, substrate specificity and enzymatic activity, protein characteristics and several well-conserved regions of amino acid sequence, the gram-negative bacterium （G^-） CrtY, cyanobacteria CrtL, chlorophyta and plant Lye-B/E, and also Ccs and Nsy related to plant Lyc-B are falling into this type of cyclase. The other one was found in G^＋ bacterium, archea and fungi and lack of the clarity of their catalytic mechanism and cofactor requirements.

关 键 词：番茄红素环化酶 环化机理 底物特异性 序列保守性 

分 类 号：Q75[生物学—分子生物学] R59[医药卫生—内科学]