Department of Chemistry and Chemical Processing Technologies, Vocational School of Technical Sciences, Iğdır University, 76000, Iğdır, Turkey.
Department of Food Engineering, Faculty of Engineering, Iğdır University, 76000, Iğdır, Turkey.
Appl Biochem Biotechnol. 2020 Oct;192(2):432-442. doi: 10.1007/s12010-020-03337-3. Epub 2020 May 11.
Tyrosinase (T3824, Sigma) enzymes were immobilized onto SnO: Sb thin films (ATO-TF) which were synthesized in laboratory conditions by spray pyrolysis technique. Immobilization of tyrosinase onto SnO: Sb thin film (ATO-TF) was confirmed by scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). The optimum pH of the immobilized tyrosinase (tyrosinase-ATO-TF) was 6.0, and the optimum temperature was found to be 30 °C. In the presence of catechol substrate of immobilized enzymes, Km and Vmax values were determined as 0.34 mM and 312.5 U/cm min, respectively. The thermal stabilities of the immobilized tyrosinase at 4 °C and 30 °C were investigated for 20, 40, and 60 min. At these temperatures and time intervals, the immobilized tyrosinase was found to be highly stable. The pH stability of the immobilized tyrosinase enzymes was incubated for 24, 48, 72, and 96 h at 4 °C temperature. The enzyme activity was determined under optimum conditions, and the activity of the immobilized tyrosinase enzymes exhibited various values for the range of pH 3.0-8.0. The storage stability of the immobilized tyrosinase enzymes at 4 °C was investigated, and 45.72% of the initial activity was maintained at the end of the seventh day. Furthermore, the reusability of the immobilized tyrosinase enzymes has been examined. The immobilized tyrosinase enzymes can be used 3 times and survived their 50% of initial activity. The ATO-TF can be used as alternative support materials for the immobilization of tyrosinase enzymes.
酪氨酸酶（T3824，西格玛）酶被固定到 SnO: Sb 薄膜（ATO-TF）上，该薄膜是通过喷雾热解技术在实验室条件下合成的。通过扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）证实了酪氨酸酶固定到 SnO: Sb 薄膜（ATO-TF）上。固定化酪氨酸酶（tyrosinase-ATO-TF）的最适 pH 值为 6.0，最适温度为 30°C。在固定化酶的儿茶酚底物存在下，Km 和 Vmax 值分别确定为 0.34 mM 和 312.5 U/cm min。在 4°C 和 30°C 下研究了固定化酪氨酸酶的热稳定性，时间分别为 20、40 和 60 min。在这些温度和时间间隔下，固定化酪氨酸酶表现出高度的稳定性。在 4°C 下孵育 24、48、72 和 96 h，研究了固定化酪氨酸酶的 pH 稳定性。在最佳条件下测定酶活性，固定化酪氨酸酶的活性在 pH 3.0-8.0 的范围内呈现出不同的值。研究了固定化酪氨酸酶在 4°C 下的储存稳定性，在第 7 天结束时，保持了初始活性的 45.72%。此外，还研究了固定化酪氨酸酶的可重复使用性。固定化酪氨酸酶可以使用 3 次，并且保持其初始活性的 50%。ATO-TF 可以作为固定化酪氨酸酶的替代支撑材料。
