Crystal structure of SPSB2 in complex with a rational designed RGD-containing cyclic peptide inhibitor of SPSB2-iNOS interaction
Crystal structure of SPSB2 in complex with a rational designed RGD-containing cyclic peptide inhibitor of SPSB2-iNOS interaction
复制标题
SPSB2与合理设计的含有RGD的SPSB2-iNOS相互作用环肽抑制剂复合物的晶体结构
DOI：
10.1016/j.bbrc.2017.05.122
复制
发表时间：
2017
影响因子：
3.1
通讯作者：
Kuang Zhihe
中科院分区：
文献类型：
--
作者：
You Tingting;Wang Yuhui;Li Kefa;Zhang Danting;Wei Huan;Luo Yanhong;Li Hua;Lu Yongzhi;Su Xunchen;Kuang Zhihe
含SPRY结构域的SOCS盒蛋白2（SPSB 2）是诱导型一氧化氮合酶（iNOS）的负调节剂，其调节iNOS的寿命并因此调节一氧化氮（NO）产生的水平。能够破坏内源性SPSB 2-iNOS相互作用并增加NO产生的抑制剂具有作为新型抗微生物和抗癌药物的潜力。在这项研究中，我们设计了一个环肽（cR 8），含有一个RGD基序和SPSB 2结合基序（DINNNV）。ITC和化学位移微扰显示cR 8与SPSB 2上的iNOS结合位点结合，Kd为671 nM，饱和转移差NMR显示cR 8与αvβ 3整合素表达细胞结合。此外，我们确定了与cR 8复合的SPSB 2的晶体结构，分辨率为1.34 nm。cR 8与SPSB 2残基形成广泛的氢键，但SPSB 2结合的iNOS肽中存在的分子内氢键的丧失可能使cR 8的结合构象不稳定，并导致SPSB 2结合亲和力的温和降低。这些结果为将来设计定点SPSB 2抑制剂提供了有用的基础。
SPRY domain-containing SOCS box protein 2 (SPSB2) is a negative regulator of inducible nitric oxide synthase (iNOS) that modulates the lifetime of iNOS and thus the levels of nitric oxide (NO) production. Inhibitors that can disrupt the endogenous SPSB2-iNOS interaction and augment NO production have potential as novel antimicrobial and anticancer drugs. In this study, we have designed a cyclic peptide (cR8), containing an RGD motif and the SPSB2 binding motif (DINNNV). ITC and chemical shift perturbation showed that cR8 binds to the iNOS binding site on SPSB2 with a Kdof 671 nM, and saturation transfer difference NMR showed that cR8 binds to αvβ3integrin-expressing cells. Moreover, we determined the crystal structure of SPSB2 in complex with cR8, at a resolution of 1.34 Å. cR8 forms extensive hydrogen bonding with SPSB2 residues, but loss of an intramolecular hydrogen bond that is present in SPSB2-bound iNOS peptide may destabilize the bound conformation of cR8 and lead to a gentle reduction in SPSB2 binding affinity. These results serve as a useful basis for designing site-directed SPSB2 inhibitors in the future.