Structural Determinants for the Interaction of Formyl Peptide Receptor 2 with Peptide Ligands
Structural Determinants for the Interaction of Formyl Peptide Receptor 2 with Peptide Ligands
复制标题
甲酰肽受体 2 与肽配体相互作用的结构决定因素
DOI：
10.1074/jbc.m113.509216
复制
发表时间：
2014-01-24
影响因子：
4.8
通讯作者：
Ye, Richard D.
中科院分区：
文献类型：
--
作者：
He, Hui-Qiong;Troksa, Erica L.;Ye, Richard D.
与甲酰肽受体1（FPR 1）不同，FPR 2/ALX（FPR 2）与不同序列的肽相互作用，但对大肠杆菌衍生的趋化肽fMet-Leu-Phe（fMLF）具有低亲和力。使用计算机建模和定点突变，我们研究了FPR 2与不同长度和组成的甲酰基肽相互作用的结构要求。在钙通量测定中，这些肽的N-甲酰基对于FPR 2和FPR 1的活化都是必需的，而C-末端氨基酸的组成对于FPR 2比FPR 1显得更重要。FPR 2与五肽（fMLFII、fMLFIK）的相互作用比与四肽（fMLFK、fMLFW）和三肽（fMLF）的相互作用更好，但与在C末端携带负电荷的肽（例如fMLFE）的相互作用仅较弱。相反，FPR 1对C末端的负电荷不太敏感。FPR 1和FPR 2的基于CXCR 4的同源性模型表明，Asp-281（7.32）对于FPR 2与某些甲酰基肽的相互作用至关重要，因为其负电荷可能与fMLF的末端COO-基团和fMLFE中带负电荷的Glu排斥。Asp-281（7.32）也可能与fMLFK中带正电荷的Lys形成稳定的相互作用。进行定点诱变以去除FPR 2中位置281处的负电荷。与野生型FPR 2相比，D281（7.32）G突变体显示出对fMLFE和fMLF的亲和力提高，对fMLFK的亲和力降低。这些结果表明，FPR 1和FPR 2使用不同的结构决定簇与甲酰基肽相互作用。
Unlike formyl peptide receptor 1 (FPR1), FPR2/ALX (FPR2) interacts with peptides of diverse sequences but has low affinity for the Escherichia coli-derived chemotactic peptide fMet-Leu-Phe (fMLF). Using computer modeling and site-directed mutagenesis, we investigated the structural requirements for FPR2 to interact with formyl peptides of different length and composition. In calcium flux assay, the N-formyl group of these peptides is necessary for activation of both FPR2 and FPR1, whereas the composition of the C-terminal amino acids appears more important for FPR2 than FPR1. FPR2 interacts better with pentapeptides (fMLFII, fMLFIK) than tetrapeptides (fMLFK, fMLFW) and tripeptide (fMLF) but only weakly with peptides carrying negative charges at the C terminus (e.g. fMLFE). In contrast, FPR1 is less sensitive to negative charges at the C terminus. A CXCR4-based homology model of FPR1 and FPR2 suggested that Asp-281(7.32) is crucial for the interaction of FPR2 with certain formyl peptides as its negative charge may be repulsive with the terminal COO- group of fMLF and negatively charged Glu in fMLFE. Asp-281(7.32) might also form a stable interaction with the positively charged Lys in fMLFK. Site-directed mutagenesis was performed to remove the negative charge at position 281 in FPR2. The D281(7.32)G mutant showed improved affinity for fMLFE and fMLF and reduced affinity for fMLFK compared with wild type FPR2. These results indicate that different structural determinants are used by FPR1 and FPR2 to interact with formyl peptides.