Institut für Technische Chemie der Universität Essen, D-4300 Essen 1, Germany.
Biotechnol Bioeng. 1992 Mar 25;39(7):725-31. doi: 10.1002/bit.260390705.
Asymmetric ultrafiltration membranes suitable for covalent bonding of urease can be prepared from membranes based upon polyamide or polysulfone. Because the original membrane polymers are not chemically reactive, they have to be converted in such a way that known reactions for enzyme fixation can be used such as the diazo, the acyl-acid, the carbodiimide, and the methylbromide reaction. The enzyme was fixed within the porous substructure of the membrane. The amount of enzyme immobilized at the membrane dense skin was found to be negligible. The kinetics can be described according to the Michaelis-Menten model. Compared to the native urease, the activity of the membrane-bonded enzyme was very low. The reasons can be sought in the transmembrane transport and in the fixation procedure as well.
可通过聚酰胺或聚砜基膜制备适合共价键合脲酶的不对称超滤膜。由于原始膜聚合物没有化学反应性，因此必须进行转化，以便可以使用已知的酶固定反应，如重氮反应、酰基酸反应、碳二亚胺反应和溴甲基反应。酶被固定在膜的多孔亚结构内。在膜致密层中固定的酶量可以忽略不计。动力学可以根据米氏方程模型来描述。与天然脲酶相比，膜结合酶的活性非常低。原因可以在跨膜传输和固定过程中找到。
