Department of Agrobiology and Agrochemistry, University of Tuscia, Via S. Camillo de Lellis, 01100 Viterbo, Italy.
Bioorg Med Chem. 2012 Jan 1;20(1):157-66. doi: 10.1016/j.bmc.2011.11.018. Epub 2011 Nov 20.
Agaricus bisporous tyrosinase was immobilized on commercial available epoxy-resin Eupergit®C250L and then coated by the Layer-by-Layer method (LbL). The two novel heterogeneous biocatalysts were characterized for their morphology, pH and storage stability, kinetic properties (K(m), V(max), V(max)/K(m)) and reusability. These biocatalysts were used for the efficient and selective synthesis of bioactive catechols under mild and environmental friendly experimental conditions. Ascorbic acid was added in the reaction medium to inhibit the formation of ortho-quinones, thus avoiding the known enzyme suicide inactivation process. Catechols were obtained mostly in quantitative yields and conversion of substrate. Tyrosinase immobilized on Eupergit®C250L and coated by the LbL method showed better catalytic activities, higher pH and storage stability, and reusability with respect to immobilized uncoated tyrosinase. Since chemical procedures to synthesize catechols are often expensive and with high environmental impact, the use of immobilized tyrosinase represents an efficient alternative for the preparation of this family of bioactive compounds.
双孢蘑菇酪氨酸酶被固定在商业可得的环氧树脂 Eupergit®C250L 上，然后通过层层（LbL）方法进行涂层。这两种新型的异质生物催化剂在形态、pH 值和储存稳定性、动力学特性（K(m)、V(max)、V(max)/K(m)）和可重复使用性方面进行了表征。这些生物催化剂在温和和环保的实验条件下用于高效和选择性合成生物活性儿茶素。在反应介质中添加抗坏血酸以抑制邻醌的形成，从而避免已知的酶自杀失活过程。儿茶素主要以定量产率和底物转化率获得。与未涂层固定化酪氨酸酶相比，固定在 Eupergit®C250L 上并通过 LbL 方法涂层的酪氨酸酶显示出更好的催化活性、更高的 pH 值和储存稳定性以及可重复使用性。由于合成儿茶素的化学方法通常昂贵且对环境影响大，因此使用固定化酪氨酸酶是制备此类生物活性化合物的有效替代方法。
