Phadtare Sumant, Vinod V P, Mukhopadhyay Kausik, Kumar Ashavani, Rao Mala, Chaudhari Raghunath V, Sastry Murali
Division of Materials Chemistry, National Chemical Laboratory, Pune 411 008, India.
Biotechnol Bioeng. 2004 Mar 20;85(6):629-37. doi: 10.1002/bit.10856.
Gold nanoparticles are excellent biocompatible surfaces for the immobilization of enzymes. However, separation of the gold nanoparticle-enzyme bioconjugate material from the reaction medium is often difficult. In this study, we investigate the assembly of the gold nanoparticles on the surface of the amine-functionalized zeolite microspheres in the formation of zeolite-gold nanoparticle "core-shell" structures and, thereafter, the use of this structure in immobilization of fungal protease. The assembly of gold nanoparticles on the zeolite surface occurs through the amine groups present in 3-aminopropyltrimethoxysilane (3-APTS). The fungal proteases bound to the massive "core-shell" structures were easily separated from the reaction medium by mild centrifugation and exhibited excellent reuse characteristics. The biocatalytic activity of fungal protease in the bioconjugate was marginally enhanced relative to the free enzyme in solution. The bioconjugate material also showed significantly enhanced pH and temperature stability and a shift in the optimum temperature of operation.
金纳米颗粒是用于固定化酶的优良生物相容性表面。然而，从反应介质中分离金纳米颗粒 - 酶生物共轭材料通常很困难。在本研究中，我们研究了金纳米颗粒在胺功能化沸石微球表面的组装，以形成沸石 - 金纳米颗粒“核壳”结构，然后将这种结构用于固定化真菌蛋白酶。金纳米颗粒在沸石表面的组装是通过3 - 氨丙基三甲氧基硅烷（3 - APTS）中存在的胺基发生的。与大量“核壳”结构结合的真菌蛋白酶通过温和离心很容易从反应介质中分离出来，并表现出优异的重复使用特性。相对于溶液中的游离酶，生物共轭物中真菌蛋白酶的生物催化活性略有增强。生物共轭材料还显示出显著增强的pH和温度稳定性以及最佳操作温度的偏移。
