講演情報
[20p-A305-22]Effects of temperature and rpm on the enzyme activity of the “floatable” enzyme devices
〇(DC)Nay San Lin1, Kota Hirayama1, Shinji Koide1, Shigeki Mayama2 (1.Tokyo Univ. of Science, 2.Tokyo Diatomology Lab.)
キーワード：
Enzyme immobilization、Floatability、Effects of temperature and rpm
Immobilization of enzymes on support materials has various advantages such as better reusability, thermal stability, and so on. However, it also has disadvantages. One of these advantages is that the immobilized enzymes do not have free mobility to react to substrates and the enzyme activity is weaker, compared to native enzymes. Hence, in our study, “floatability” of enzyme devices was focused by changing temperature and rpm. We have fabricated enzyme devices using five types of SiO2 materials: diatom frustules collected from Chiba prefecture and cultured in our laboratory, mesoporous silica, diatomaceous earth (DE) 1 (white), DE 2 (red), and glass beads as support materials. The utilized enzyme used for the enzyme devices is papain, a commercially available plant enzyme derived from Papaya. The SiO2 materials were silanized with Carboxyethylsilanetriol, disodium salt, 25% in water (COOH) and the papain molecules were chemically crosslinked to them using N-hydroxysuccinimide (NHS) and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (WSC). Then, the enzyme activity of the fabricated enzyme devices was analyzed using a Duetta spectrometer (Horiba Ltd., Kyoto, Japan) by focusing on the 405 nm absorption wavelength of the substrate, Bz-L-Arg-pNA · HCl [L-BAPA]. The enzyme reaction experiments were performed in three temperatures: room temperature, 37 ºC and 60 ºC. At higher temperature, the enzyme devices showed better performances. However, when the rpm value was varied, no remarkable changes were observed in the enzyme activity. This might be due to the use of small amount of SiO2 materials in fabricating the enzyme devices. In all conditions, the enzyme devices with frustules showed higher enzyme activity than those with other SiO2 materials since the cultured frustules have higher floatability than other SiO2 materials.