Kang Guo-Zhang, Wang Yong-Hua, Guo Tian-Cai, Zhu Yun-Ji, Guan Chun-Yun
National Engineering Research Centre for Wheat, Henan Agricultural Unerversity, Zhengzhou 450002, China.
Yi Chuan. 2006 Jan;28(1):110-6.
Starch, the most common form of stored carbon in plants, is both the major food source for mankind and important raw material for many industries. It is composed of two types of alpha-1,4-linked glucan polymer: essentially unbranched amylose and regularly branched amylopectin, and synthesized in photosynthetic and non-photosynthetic organs. Starch is synthesized via four committed enzyme steps: ADP-Glc pyrophosphorylase, which synthesizes sugar nucleotide precursors; starch synthase, which extends the alpha-1,4-linked glucan chains using ADP-Glc; starch-branching enzymes, which introduce alpha-1,6 branch points to form amylopectin; and starch debranching enzymes, which hydrolyze alpha-1,6 branches in glucans. In this paper, recent advances in biochemical characterizations and gene engineering concerning these enzymes were reviewed, and the achievements in gene engineering involved in manipulation of starch amount and quality were also cited.
淀粉是植物中储存碳的最常见形式，既是人类的主要食物来源，也是许多行业的重要原材料。它由两种α-1,4-连接的葡聚糖聚合物组成：基本无分支的直链淀粉和规则分支的支链淀粉，并在光合和非光合器官中合成。淀粉通过四个关键酶步骤合成：合成糖核苷酸前体的ADP-葡萄糖焦磷酸化酶；利用ADP-葡萄糖延伸α-1,4-连接的葡聚糖链的淀粉合酶；引入α-1,6分支点以形成支链淀粉的淀粉分支酶；以及水解葡聚糖中α-1,6分支的淀粉脱支酶。本文综述了这些酶在生化特性和基因工程方面的最新进展，并列举了在淀粉数量和质量操纵方面基因工程的成果。
