Kraus Michael, Grimm Clemens, Seibel Jürgen
Department of Organic Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Chembiochem. 2016 Jan 1;17(1):33-6. doi: 10.1002/cbic.201500514. Epub 2015 Dec 2.
Sucrose phosphorylases have been applied in the enzymatic production of glycosylated compounds for decades. However, several desirable acceptors, such as flavonoids or stilbenoids, that exhibit diverse antimicrobial, anticarcinogenic or antioxidant properties, remain poor substrates. The Q345F exchange in sucrose phosphorylase from Bifidobacterium adolescentis allows efficient glucosylation of resveratrol, (+)-catechin and (-)-epicatechin in yields of up to 97 % whereas the wild-type enzyme favours sucrose hydrolysis. Three previously undescribed products are made available. The crystal structure of the variant reveals a widened access channel with a hydrophobic aromatic surface that is likely to contribute to the improved activity towards aromatic acceptors. The generation of this channel can be explained in terms of a cascade of structural changes arising from the Q345F exchange. The observed mechanisms are likely to be relevant for the design of other tailor-made enzymes.
几十年来，蔗糖磷酸化酶一直应用于糖基化化合物的酶促生产。然而，一些具有多种抗菌、抗癌或抗氧化特性的理想受体，如黄酮类化合物或芪类化合物，仍然是较差的底物。青春双歧杆菌蔗糖磷酸化酶中的Q345F交换可使白藜芦醇、（+）-儿茶素和（-）-表儿茶素高效糖基化，产率高达97%，而野生型酶则有利于蔗糖水解。三种以前未描述的产物得以制备。该变体的晶体结构显示出一个具有疏水芳香表面的加宽通道，这可能有助于提高对芳香受体的活性。这个通道的产生可以用Q345F交换引起的一系列结构变化来解释。观察到的机制可能与其他定制酶的设计有关。
