University of Queensland, Centre for Nutrition and Food Sciences and LCAFS, Hartley Teakle Building, Brisbane, Qld 4072, Australia.
Biomacromolecules. 2010 Dec 13;11(12):3539-47. doi: 10.1021/bm1010189. Epub 2010 Nov 8.
Modeling the chain-length distributions (CLDs, the molecular weight distributions of individual branches) in a polymer system can be exploited to obtain information on the underlying (bio)synthesis mechanisms. Such a model is developed for starch (a highly branched glucose polymer), taking into account multiple isoforms of the three types of enzymatic mechanisms contributing directly to the CLD: propagation, branching, and debranching. The resulting CLD is given by two parameters and can thus be represented by a point in a two-dimensional phase diagram. The model implies that all native-starch amylopectin CLDs are confined to a line in this phase diagram, an inference supported by fitting data for a wide range of plants. This gives new ways to classify mutants and suggests useful directions for plant engineering (e.g., which isoforms could be targeted to give long branches, which are nutritionally desirable).
对聚合物系统中的链长分布（CLD，即各支链的分子量分布）进行建模，可以用来获取有关潜在（生物）合成机制的信息。该模型针对淀粉（一种高度支化的葡萄糖聚合物）进行了开发，考虑了三种直接影响 CLD 的酶机制的多个同工型：聚合、分支和去分支。所得的 CLD 由两个参数给出，因此可以用二维相图中的一个点来表示。该模型表明，所有天然淀粉支链淀粉的 CLD 都局限于该相图中的一条线上，这一推断得到了广泛的植物数据拟合的支持。这为突变体的分类提供了新的方法，并为植物工程学提供了有用的方向（例如，应该针对哪些同工型来获得营养上可取的长支链）。
