Lee D D, Lee G K, Reilly P J, Lee Y Y
Biotechnol Bioeng. 1980 Jan;22(1):1-17. doi: 10.1002/bit.260220102.
Data reported here and previously indicate that when dextrin is hydrolyzed in the presence of immobilized glucoamylase, use of a larger average molecular weight substrate leads to lower overall rates of hydrolysis, while the maltose concentration during the bulk of the reaction and the maximum glucose concentration are lower than when the soluble form of the enzyme is employed under the same conditions. Computer simulation of the system demonstrated that all three observations were caused by pore diffusion limitation: the first by slow diffusion of substrate, the second by slow diffusion of intermediates, and the third by slow diffusion of glucose. Follow-up experiments with glucoamylase immobilized to particles of different sizes confirmed this finding, as results with the smallest beads were identical to those with soluble glucoamylase.
此处报告的数据以及之前的数据表明，当糊精在固定化糖化酶存在的情况下被水解时，使用平均分子量更大的底物会导致总体水解速率降低，而在反应主体阶段的麦芽糖浓度以及最大葡萄糖浓度低于在相同条件下使用酶的可溶形式时的浓度。对该系统进行计算机模拟表明，所有这三个观察结果均由孔扩散限制所致：第一个是由于底物扩散缓慢，第二个是由于中间体扩散缓慢，第三个是由于葡萄糖扩散缓慢。用固定在不同大小颗粒上的糖化酶进行的后续实验证实了这一发现，因为最小珠子的实验结果与可溶糖化酶的实验结果相同。
