Hsiao Yu-Shan, Parker Dane, Ratner Adam J, Prince Alice, Tong Liang
Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Biochem Biophys Res Commun. 2009 Mar 13;380(3):467-71. doi: 10.1016/j.bbrc.2009.01.108. Epub 2009 Jan 23.
Currently there is pressing need to develop novel therapeutic agents for the treatment of infections by the human respiratory pathogens Pseudomonas aeruginosa and Streptococcus pneumoniae. The neuraminidases of these pathogens are important for host colonization in animal models of infection and are attractive targets for drug discovery. To aid in the development of inhibitors against these neuraminidases, we have determined the crystal structures of the P. aeruginosa enzyme NanPs and S. pneumoniae enzyme NanA at 1.6 and 1.7A resolution, respectively. In situ proteolysis with trypsin was essential for the crystallization of our recombinant NanA. The active site regions of the two enzymes are strikingly different. NanA contains a deep pocket that is similar to that in canonical neuraminidases, while the NanPs active site is much more open. The comparative studies suggest that NanPs may not be a classical neuraminidase, and may have distinct natural substrates and physiological functions. This work represents an important step in the development of drugs to prevent respiratory tract colonization by these two pathogens.
目前迫切需要开发新型治疗药物，用于治疗由人类呼吸道病原体铜绿假单胞菌和肺炎链球菌引起的感染。这些病原体的神经氨酸酶对于感染动物模型中的宿主定植至关重要，是药物研发的有吸引力的靶点。为了协助开发针对这些神经氨酸酶的抑制剂，我们分别以1.6埃和1.7埃的分辨率确定了铜绿假单胞菌酶NanPs和肺炎链球菌酶NanA的晶体结构。用胰蛋白酶进行原位蛋白水解对于我们重组NanA的结晶至关重要。这两种酶的活性位点区域明显不同。NanA含有一个与典型神经氨酸酶中相似的深口袋，而NanPs的活性位点则更为开放。比较研究表明，NanPs可能不是一种经典的神经氨酸酶，可能具有不同的天然底物和生理功能。这项工作是开发预防这两种病原体呼吸道定植药物的重要一步。
