Conservative Change to the Phosphate Moiety of Cyclic Diguanylic Monophosphate Remarkably Affects Its Polymorphism and Ability To Bind DGC, PDE, and PilZ Proteins
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- 作者：Jingxin Wang ; Jie Zhou ; Gregory P. Donaldson ; Shizuka Nakayama ; Lei Yan ; Yiu-fai Lam ; Vincent T. Lee ; Herman O. Sintim
- 刊名：Journal of the American Chemical Society
- 出版年：2011
- 出版时间：June 22, 2011
- 年：2011
- 卷：133
- 期：24
- 页码：9320-9330
- 全文大小：1256K
- 年卷期：v.133,no.24(June 22, 2011)
- ISSN：1520-5126
文摘
The cyclic dinucleotide c-di-GMP is a master regulator of bacterial virulence and biofilm formation. The activations of c-di-GMP metabolism proteins, diguanylate cyclases (DGCs) and phosophodiesterases (PDEs), usually lead to diametrically opposite phenotypes in bacteria. Analogues of c-di-GMP, which can selectively modulate the activities of c-di-GMP processing proteins, will be useful chemical tools for studying and altering bacterial behavior. Herein we report that a conservative modification of one of the phosphate groups in c-di-GMP with a bridging sulfur in the phosphodiester linkage affords an analogue called endo-S-c-di-GMP. Computational, NMR (including DOSY), and CD experiments all reveal that, unlike c-di-GMP, endo-S-c-di-GMP does not readily form higher aggregates. The lower propensity of endo-S-c-di-GMP to form aggregates (as compared to that of c-di-GMP) is probably due to a higher activation barrier to convert from the 鈥渙pen鈥?conformer (where the two guanines are on opposite faces) to the 鈥渃losed鈥?conformer (where the two guanines are on the same face). Consequently, endo-S-c-di-GMP has selectivity for proteins that bind monomeric but not dimeric c-di-GMP, which form from the 鈥渃losed鈥?conformer. For example, endo-S-c-di-GMP can inhibit the hydrolysis of c-di-GMP by RocR (a PDE enzyme that binds monomeric c-di-GMP) but did not bind to Alg44 (a PilZ protein) or regulate WspR (a DGC enzyme that has been shown to bind to dimeric c-di-GMP). This work demonstrates that selective binding to different classes of c-di-GMP binding proteins could be achieved by altering analogue conformer populations (conformational steering). We provide important design principles for the preparation of selective PDE inhibitors and reveal the role played by the c-di-GMP backbone in c-di-GMP polymorphism and binding to processing proteins.