亲水性交联聚合物载体的合成表征及其固定化α-淀粉酶

Synthesis and Properties of Hydrophilic Copolymer Support for α-amylase

选用丙烯酰胺(AM)、N-羟基琥珀酰亚胺为单体(NHS),以N,N/-亚甲基双丙烯酰胺(MBAA)为交联剂,以乙醇水溶液为制孔剂条件下进行反相悬浮聚合,得到珠状共聚物载体,该载体是一种新的酶载体形式,在国内外的相关文献中均未见报道.用红外光谱、扫描电子显微镜测定其结构和表观活性.结果表明,在固定单体配比[W(AM)/W(NHS)=10∶1]和致孔剂用量的情况下,测得交联剂用量为4%时,交联聚合物载体的溶胀性最好(287.5%);交联剂用量为5%时,交联聚合物载体固定化α-淀粉酶表现出高的表观活性(522.53U/g).测得固定化酶载体表现出良好的操作稳定性.比较固定化酶和游离态酶的最适反应温度发现,固定化酶的最适反应温度(70℃)比游离态酶高20℃;固定化酶的最适反应pH值范围较游离态酶广.

Reactive, macroporous and beaded acrylamide （ AM ） -N -hydroxysuccinimide （NHS） -N, N＇-methylene-bis acrylamide （MBAA） copolymers cartier of widely varying densities were synthesized with solution of ethanol as porogenic agent by inverse suspension copolymerization. This cartier has not been reported until now in the literature. The support structure and pore distribution were characterized by Fourier transform infrared spectroscopy and scanning electron microscope. At fixed conditions of monomer [ W（ AM）/W（NHS） = 1： 10] and porogenic agent, immobilized enzyme swelling property of 287.5% was obtained with a polymer with ω =4% crosslinking agent; immobilized enzyme activity of 522.53 U/g was obtained with a polymer with ω= 5% crosslinking agent. The activity of the immobilized enzyme reached a relatively steady value after the immobilized enzyme was used for 4 times. The effects of hydrolyzation condition such as pH, temperature on apparent activity of the immobilized enzyme were investigated. The results showed that the properties of immobilized enzyme were markedly better than that of free enzyme. The appropriate temperature of hydrolyzation of immobilized enzyme was 20 ℃ over that of free enzyme; while the appropriate pH of immobilized enzyme was wider.