多酸型酪氨酸酶抑制剂的设计合成与性能

Tyrosinase (1.14.18.1) is the key enzyme during melanin biosynthesis which catalyzes the hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine (DOPA) and the oxidation of L-DOPA to dopaquinone. Therefore, the development of tyrosinase inhibitors has received much attention. natural product and organic molecules are now the two main classes of tyrosinase inhibitors. Worldwide sales of inorganic drugs are growing rapidly. However, few inorganic ligands have been reported that can inhibit tyrosinase the activity. As important inorganic drug candidates, polyoxometalates (POMs) have shown promising antiviral and antitumor activities for more than a decade. Polyoxometalates (POMs) are an oxygen rich class of inorganic cluster compounds with much diversity in size, composition, and function. Several research groups have reported detailed studies of the interaction between POMs and their target proteins. POMs may also be potential tyrosinase inhibitors. Applicants will be based on our research around the synthesis, characterization and the antityrosinase activities of Keggin and Dawson polyoxometalates and their coordination polymers. First, taking Keggin and Dawson polyoxometalates as the object of study, we intend to find out whether these compounds possess antityrosinase activities and determine their inhibitory efficiency. By discussing the structure-activity relationship of these compounds, we try to correlate their inhibitory efficiency to structural features. Then, based on these, we further study the antibrowning mechanism of Keggin and Dawson polyoxometalates and their coordination polymers to guide the structure transformation. By doing these, we expect to develop novel tyrosinase inhibitors from polyoxometalates. Finally, we try to search for a putative polyoxometalates-binding site on tyrosinase by using four complementary approaches: (1) the tyrosine assay with tyrosinase holoenzyme, (2) af?nity chromatography with an immobilized polyoxometalates, (3) trypsin proteolysis, and (4) site-directed mutagenesis. In addition, inhibitory mechanism of Keggin and Dawson polyoxometalates and their coordination polymers on related proteins of melanin synthesis will be studied. It is expected that all these research will provide an important basis for the practical application of polyoxometalates and their coordination polymers.

申请者将立足于已有的研究积累，围绕多金属氧酸盐及其配位聚合物的合成、表征和其对酪氨酸酶抑制作用的研究展开。申请者拟以蘑菇酪氨酸酶为研究对象，研究多酸型酪氨酸酶的抑制剂对酪氨酸酶的抑制作用机理，讨论构效关系，希望建立多金属氧酸盐及其配位聚合物的结构与对酪氨酸酶抑制作用及其酶效应的相关性。在此基础上，深入研究多金属氧酸盐及其配位聚合物的抗酶促褐变机理，以指导后期结构改造，期望开发出新型酪氨酸酶抑制剂；再通过使用对酪氨酸酶全酶检测、紫外、CD谱、X－射线、核磁共振、飞行质谱、蛋白质序列测定等方法分析多金属氧酸盐和酪氨酸酶的复合物结构，探讨酪氨酸酶与多金属氧酸盐及其配位聚合物结合位点是否存在，揭示其对酪氨酸酶抑制模式，并研究抑制剂对小鼠B16F10细胞的存活力及其黑色素生成的影响。揭示多金属氧酸盐及其配位聚合物对黑色素合成相关蛋白的调控的机理，为多金属氧酸盐及其配位聚合物实际应用提供重要理论依据。

课题组围绕设计合成新型的高活性的酪氨酸酶抑制剂，并深入探讨酪氨酸酶与多金属氧酸盐及其配位聚合物结合位点是否存在，揭示其对酪氨酸酶抑制模式，提出抑制剂和酶分子间结合作用的分子模型，探讨多金属氧酸盐及其配位聚合物对黑色素合成相关蛋白的调控，研究其对酪氨酸酶是否有抑制作用及抑制程度，评价其抑酶活性，讨论构效关系，希望建立多金属氧酸盐及其配位聚合物的结构与对酪氨酸酶抑制作用及其酶的效应的相关性。在此基础上，深入研究多金属氧酸盐及其配位聚合物的抗酶促褐变机理，以指导后期结构改造，期望开发出新型酪氨酸酶抑制剂。发表论文16篇，其中food chem 5篇，出席学术会议5次。培养研究生7人。