Conversion of beta-carotene into astaxanthin: Two separate enzymes or a bifunctional hydroxylase-ketolase protein?
Conversion of beta-carotene into astaxanthin: Two separate enzymes or a bifunctional hydroxylase-ketolase protein?
复制标题
DOI：
10.1186/1475-2859-7-3
复制
发表时间：
2008-02-20
影响因子：
6.4
通讯作者：
Barredo JL
中科院分区：
文献类型：
--
作者：
Martín JF;Gudiña E;Barredo JL
虾青素是一种在动物营养和人类健康方面具有重要意义的叶黄素。该保健分子在保健品行业的市场前景十分广阔。虾青素由几种细菌、藻类和植物通过两种酶的顺序作用从β-胡萝卜素合成：β-胡萝卜素3，3 '-羟化酶，其在β-胡萝卜素的两个β-紫罗兰酮环中的每一个的3（和3'）位引入羟基，以及β-胡萝卜素酮醇酶，其在β-紫罗兰酮环的碳4和4'处引入酮基。虾青素也由酵母样担子菌Xanthophyllomyces dendrorhous产生。两个研究小组同时克隆了一个与β-胡萝卜素转化为虾青素有关的基因crtS。X.卷枝毛霉中的树状突变体和表达分析揭示，CrtS酶是P-450单加氧酶家族的β-胡萝卜素羟化酶，其将β-胡萝卜素转化为羟基化衍生物β-隐黄素和玉米黄质，但它在该真菌中不形成虾青素或酮醇化中间体。已提出CrtS蛋白具有双功能β-胡萝卜素羟化酶-酮醇酶活性。支持和反对这一假设的证据进行了详细的分析，在这篇评论。
Astaxanthin is a xanthophyll of great interest in animal nutrition and human health. The market prospect in the nutraceutics industries for this health-protective molecule is very promising. Astaxanthin is synthesized by several bacteria, algae and plants from β-carotene by the sequential action of two enzymes: a β-carotene, 3,3'-hydroxylase that introduces an hydroxyl group at the 3 (and 3') positions of each of the two β-ionone rings of β-carotene, and a β-carotene ketolase that introduces keto groups at carbons 4 and 4' of the β-ionone rings. Astaxanthin is also produced by the yeast-like basidiomycete Xanthophyllomyces dendrorhous. A gene crtS involved in the conversion of β-carotene to astaxanthin has been cloned simultaneously by two research groups. Complementation studies of X. dendrorhous mutants and expression analysis in Mucor circinelloides reveals that the CrtS enzyme is a β-carotene hydroxylase of the P-450 monooxygenase family that converts β-carotene to the hydroxylated derivatives β-cryptoxanthin and zeaxanthin, but it does not form astaxanthin or the ketolated intermediates in this fungus. A bifunctional β-carotene hydroxylase-ketolase activity has been proposed for the CrtS protein. The evidence for and against this hypothesis is analyzed in detail in this review.
登录
查看更多内容
影响因子：
2.6
作者：
GOLUBEV, WI
通讯作者：
GOLUBEV, WI
影响因子：
2.1
作者：
Breitenbach, J;Misawa, N;Sandmann, G
通讯作者：
Sandmann, G
影响因子：
5
作者：
Choi, Seon-Kang;Matsuda, Satoru;Misawa, Norihiko
通讯作者：
Misawa, Norihiko
影响因子：
3.2
作者：
Hannibal, L;Lorquin, J;Giraud, E
通讯作者：
Giraud, E
影响因子：
3.8
作者：
ANDREWES, AG;PHAFF, HJ;STARR, MP
通讯作者：
STARR, MP