Control of reaction with immobilized enzyme using polymeric gel

1.测定了聚N-异丙基丙烯酰胺（NIPA）凝胶在聚乙二醇（PEG 200、1000、6000、20000和50000）+水混合物中的溶胀行为，以及凝胶内外PEG的浓度。扩展的Flory-Huggins公式能够关联凝胶在PEG+水混合物中的溶胀行为。测定了含有二氧化硅粒子的水溶液中NIPA凝胶的溶解度和NIPA凝胶内外的浓度。通过约5 nm筛目尺寸的NIPA凝胶完全排除二氧化硅颗粒（5 nm）。讨论了NIPA凝胶筛孔尺寸与分离效率的关系。效率值随PEG分子量的增加而增加，随筛目尺寸的减小而增加。并讨论了PEG分子大小与效率的关系。当筛孔大小与PEG分子大小相对应时，我们发现约20%的PEG分子可以渗透到凝胶中。另一方面，在Xi<3.3nm的范围内完全排除大于PEG 6000的PEG分子。测定了含酶（葡糖淀粉酶）的NIPA凝胶在淀粉+水混合物中的溶胀行为和NIPA凝胶外葡萄糖的浓度。葡萄糖浓度随温度的升高而降低，这是因为NIPA凝胶体积随温度的升高而减小。从这个结果，我们发现，它是可能的控制固定化酶反应，通过使用NIPA凝胶。

1. Swelling behaviors of poly (N-isopropylacrylamide) (NIPA) gelinpoly (ethylene glycol) (PEG200,1000,6000,20000 and 50000) +water mixtures and concentrations of PEG inside and outside the NIPA gel were measured. An extended Flory-Huggins formula was able to correlate the swelling behavior of the gel in PEG+water mixtures.2. Volumes of NIPA gel and concentrations inside and outside NIPA gel in aqueous solution containing silica particles were measured. The silica particle (5nm) was excluded perfectly by about 5nm mesh size of NIPA gel. Relationship between mesh size of NIPA gel and separation efficiency was discussed. The values of efficiency increased with increasing of the molecular weight of PEGs and increased with decreasing of mesh size. Relationship between molecular sizes of PEGs and efficiency was also discussed. When mesh sizes are correspond to molecular sizes of PEGs, we found that about 20% amount of PEG molecules can penetrate into the gel. On the other hand, PEGs molecules larger than PEG6000 were perfectly excluded in the range ; xi<3.3nm.3. Swelling behaviors of NIPA gel containing enzyme (glucoamylase) in starch+water mixtures and concentrations of glucose outside the NIPA gel were measured. The concentration of glucose decreased with increasing of temperature because the volume of NIPA gel decreased with increasing of temperature. From this results, we found that it is possible to control immobilized enzyme reaction by using NIPA gel.