State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
J Agric Food Chem. 2021 Dec 15;69(49):14951-14960. doi: 10.1021/acs.jafc.1c06531. Epub 2021 Nov 30.
Glycogen-like glucan (GnG), a hyperbranched glucose polymer, has been receiving increasing attention to generate synthetic polymers and nanoparticles. Importantly, different branching patterns strongly influence the functionality of GnG. To uncover ways of obtaining different GnG branching patterns, a series of GnG with radius from 22.03 to 27.06 nm were synthesized using sucrose phosphorylase, α-glucan phosphorylase (GP), and branching enzyme (BE). Adjusting the relative activity ratio of GP and BE (GP/BE) made the molecular weight (MW) distribution of intermediate GnG products follow two different paths. At a low GP/BE, the GnG developed from "small to large" during the synthetic process, with the MW increasing from 6.15 × 10 to 1.21 × 10 g/mol, and possessed a compact structure. By contrast, a high GP/BE caused the "large to small" model, with the MW reduction of GnG from 1.62 × 10 to 1.21 × 10 g/mol, and created a loose external structure. The higher GP activity promoted the elongation of external chains and restrained chain transfer by the BE to the inner zone of GnG, which would modulate the loose-tight structure of GnG. These findings provide new useful insights into the construction of structurally well-defined nanoparticles.
糖原样葡聚糖 (GnG) 是一种高度支化的葡萄糖聚合物，因其能够生成合成聚合物和纳米颗粒而受到越来越多的关注。重要的是，不同的支化模式强烈影响 GnG 的功能。为了揭示获得不同 GnG 支化模式的方法，我们使用蔗糖磷酸化酶、α-葡聚糖磷酸化酶 (GP) 和分支酶 (BE) 合成了一系列半径为 22.03 至 27.06nm 的 GnG。通过调整 GP 和 BE 的相对活性比 (GP/BE)，使中间 GnG 产物的分子量 (MW) 分布遵循两种不同的路径。在低 GP/BE 下，GnG 在合成过程中由“小变大”，MW 从 6.15×10 增加到 1.21×10g/mol，具有紧凑的结构。相比之下，高 GP/BE 会导致“大变小”的模型，MW 从 1.62×10 降低到 1.21×10g/mol，且会创造出一个疏松的外部结构。较高的 GP 活性促进了外部链的伸长，并通过 BE 抑制了链转移到 GnG 的内层，这会调节 GnG 的松散-紧密结构。这些发现为构建结构明确的纳米颗粒提供了新的有用见解。
