Ritsema Tita, Smeekens Sjef C M
Molecular Plant Physiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
J Plant Physiol. 2003 Jul;160(7):811-20. doi: 10.1078/0176-1617-01029.
Fructans, or polyfructosylsucroses, are storage carbohydrates present in many higher plants. They are also considered healthy food ingredients. Engineering crops into high level production of specific fructan molecules is one of the mayor strategic research goals. Understanding the properties of fructosyltransferases is important, in order to direct the synthesis of fructans. In plants at least two fructosyltransferases are needed to synthesise fructans. One enzyme synthesises the fructan trisaccharide 1-kestose, the next enzyme uses 1-kestose for elongation and/or modification, producing longer fructans. The specificity of fructosyltransferases determines the type of glycosidic bond formed and the donor and acceptor substrates used. This enables the synthesis of many structurally diverse fructans. The production of these molecules in crops such as sugar beet and potato makes the commercial use of fructans feasible.
果聚糖，即多聚果糖基蔗糖，是许多高等植物中存在的储存性碳水化合物。它们也被视为健康的食品成分。将作物改造为能高水平生产特定果聚糖分子是主要的战略研究目标之一。了解果糖基转移酶的特性对于指导果聚糖的合成很重要。在植物中，合成果聚糖至少需要两种果糖基转移酶。一种酶合成果聚糖三糖1-蔗果三糖，另一种酶利用1-蔗果三糖进行延伸和/或修饰，产生更长的果聚糖。果糖基转移酶的特异性决定了所形成糖苷键的类型以及所使用的供体和受体底物。这使得能够合成许多结构多样的果聚糖。在甜菜和马铃薯等作物中生产这些分子使得果聚糖的商业应用成为可能。
