Nada Sharif S, Gilbert Robert G
Joint International Research Laboratory of Agriculture and Agri-Product Safety, College of Agriculture, Yangzhou University, Yangzhou, Jiangsu 225009, China.
Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072, Australia.
ACS Omega. 2017 Aug 31;2(8):5221-5227. doi: 10.1021/acsomega.7b00922.
Glycogen and starch are complex branched polymers of glucose that serve as units of glucose storage in animals and plants, respectively. Changes in the structure of these molecules have been linked to changes in their respective functional properties. Enzymatic models of starch synthesis have provided valuable insights into the biosynthetic origins of starch structure and functional properties but have not successfully been applied to glycogen despite the structural similarities between the two polymers. Modifications to biosynthetic models of starch structure were tested for applicability to glycogen. Mathematical evidence is provided showing the necessity (which has hitherto been in doubt) of considering the effects of catabolic (degradative) enzymes in biosynthesis-based approaches that seek to accurately describe the molecular weight distributions of individual chains of glycogen formed in vivo through glycogenesis. This finding also provides future direction for inferring the dependence of enzyme activities on substrate chain length from in vivo data.
糖原和淀粉是葡萄糖的复杂分支聚合物，分别作为动物和植物中葡萄糖的储存单元。这些分子结构的变化与它们各自的功能特性变化有关。淀粉合成的酶模型为淀粉结构和功能特性的生物合成起源提供了有价值的见解，但尽管这两种聚合物在结构上有相似之处，却尚未成功应用于糖原。对淀粉结构的生物合成模型进行了修改，以测试其对糖原的适用性。提供了数学证据，表明在基于生物合成的方法中考虑分解代谢（降解）酶的影响的必要性（迄今为止一直存在疑问），这些方法旨在准确描述通过糖原生成在体内形成的糖原单链的分子量分布。这一发现也为从体内数据推断酶活性对底物链长度的依赖性提供了未来的方向。
