Hurtado-Guerrero Ramon, van Aalten Daan M F
Division of Biological Chemistry & Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK.
Chem Biol. 2007 May;14(5):589-99. doi: 10.1016/j.chembiol.2007.03.015.
Chitinases hydrolyse the beta(1,4)-glycosidic bonds of chitin, an essential fungal cell wall component. Genetic data on a subclass of fungal family 18 chitinases have suggested a role in cell wall morphology. Specific inhibitors of these enzymes would be useful as tools to study their role in cell wall morphogenesis and could possess antifungal properties. Here, we describe the crystallographic structure of a fungal "plant-type" family 18 chitinase, that of Saccharomyces cerevisiae CTS1. The enzyme is active against 4-methylumbelliferyl chitooligosaccharides and displays an unusually low pH optimum for activity. A library screen against ScCTS1 yielded hits with Ki 's as low as 3.2 microM. Crystal structures of ScCTS1 in complex with inhibitors from three series reveal striking mimicry of carbohydrate substrate by small aromatic moieties and a pocket that could be further exploited in optimization of these inhibitors.
几丁质酶可水解几丁质的β(1,4)-糖苷键，几丁质是真菌细胞壁的一种重要成分。关于真菌18家族几丁质酶一个亚类的遗传数据表明其在细胞壁形态中发挥作用。这些酶的特异性抑制剂作为研究其在细胞壁形态发生中作用的工具将很有用，并且可能具有抗真菌特性。在此，我们描述了一种真菌“植物型”18家族几丁质酶的晶体结构，即酿酒酵母CTS1的晶体结构。该酶对4-甲基伞形酮基几丁寡糖具有活性，并且显示出异常低的最适pH值以发挥活性。针对ScCTS1的文库筛选产生了低至3.2 microM的Ki值的命中物。ScCTS1与来自三个系列的抑制剂形成复合物的晶体结构揭示了小的芳香部分对碳水化合物底物的显著模拟以及一个可在这些抑制剂的优化中进一步利用的口袋。
