Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Japan.
J Biomater Sci Polym Ed. 2011;22(12):1551-61. doi: 10.1163/092050610X514557. Epub 2010 Aug 30.
Egg white lysozyme was chemically modified by PEGylated PAMAM 1st, 2nd and 3rd generation dendrons, which had 2, 4 and 8 PEG arms, respectively. The number of PEG chains introduced to the lysozyme molecule drastically increased with an increase in dendron generation, although the number of PEGylated PAMAM dendrons introduced decreased due to steric repulsion. The lytic activity of lysozyme to Micrococcus luteus cells was effectively inhibited by conjugating PEGylated PAMAM dendron to the lysozyme, indicating steric stabilization of PEG chains at the surface of lysozyme molecule. In addition, the enzymatic reaction of the lysozyme with oligosaccharide substrate was apparently accelerated by a substrate condensation effect due to the multi-armed structure of PEG.
蛋清溶菌酶首先通过 PEG 化的 PAMAM 第一代、第二代和第三代树枝状分子进行化学修饰，这些树枝状分子分别具有 2、4 和 8 个 PEG 臂。尽管由于空间位阻，引入到溶菌酶分子上的 PEG 化 PAMAM 树枝状分子的数量减少，但随着树枝状分子代的增加，引入到溶菌酶上的 PEG 链数量急剧增加。通过将 PEG 化 PAMAM 树枝状分子与溶菌酶结合，有效抑制了溶菌酶对微球菌细胞的裂解活性，表明 PEG 链在溶菌酶分子表面的空间稳定化。此外，由于 PEG 的多臂结构，溶菌酶与寡糖底物的酶反应明显由于底物缩合效应而加速。
