Luo Z, Fan X, Zhou N, Hiraoka M, Luo J, Kaji H, Huang Z
Kimmel Cancer Center and Department of Biochemistry and Molecular Pharmacology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Biochemistry. 2000 Nov 7;39(44):13545-50. doi: 10.1021/bi000633q.
The viral macrophage inflammatory protein II (vMIP-II) shows a broad spectrum interaction with both CC and CXC chemokine receptors including CCR5 and CXCR4, two principal coreceptors for the cellular entry of human immunodeficiency virus type 1 (HIV-1). Recently, we have shown that a synthetic peptide derived from the N-terminus of vMIP-II, designated as V1, is a potent antagonist of CXCR4 but not CCR5 [Zhou, N., et al. (2000) Biochemistry 39, 3782-3787]. In this study, we synthesized a series of new peptides derived from other regions of vMIP-II and characterized their binding activities with both CXCR4 and CCR5. The results provided further support for the notion that the N-terminus of vMIP-II is the major determinant for CXCR4 recognition and that vMIP-II probably interacts with other chemokine receptors such as CCR5 with different sequence and conformational determinants. To understand the structure-function relationship of V1 peptide, its solution conformation was studied using circular dichroism spectroscopy, which showed a random conformation similar to that of the corresponding N-terminus in native vMIP-II. In addition, we synthesized a series of mutant analogues of V1 containing alanine, glycine, or phenylalanine substitution at various positions. Residues Val-1, Arg-7, and Lys-9 of V1 peptide were found to be critical for receptor interaction, because single alanine replacement at these positions dramatically decreased peptide binding to CXCR4. In contrast, alanine or phenylalanine substitution at Cys-11 led to significant enhancement in peptide affinity for CXCR4. Finally, we showed that V1 peptide inhibits HIV-1 replication in CXCR4(+) T-cell lines. These studies provide new insights into the structure-function relationship of V1 peptide and demonstrate that this peptide may be a lead for the development of therapeutic agents.
病毒巨噬细胞炎性蛋白II（vMIP-II）与CC和CXC趋化因子受体具有广泛的相互作用，包括CCR5和CXCR4，这两个是1型人类免疫缺陷病毒（HIV-1）细胞进入的主要共受体。最近，我们发现从vMIP-II的N端衍生的一种合成肽，命名为V1，是CXCR4的有效拮抗剂，但不是CCR5的拮抗剂[周，N.等人（2000年）《生物化学》39，3782 - 3787]。在本研究中，我们合成了一系列源自vMIP-II其他区域的新肽，并对它们与CXCR4和CCR5的结合活性进行了表征。结果进一步支持了这样一种观点，即vMIP-II的N端是CXCR4识别的主要决定因素，并且vMIP-II可能与其他趋化因子受体如CCR5以不同的序列和构象决定因素相互作用。为了理解V1肽的结构 - 功能关系，使用圆二色光谱对其溶液构象进行了研究，结果显示其具有类似于天然vMIP-II中相应N端的随机构象。此外，我们合成了一系列V1的突变类似物，在不同位置含有丙氨酸、甘氨酸或苯丙氨酸取代。发现V1肽的Val-1、Arg-7和Lys-9残基对于受体相互作用至关重要，因为在这些位置的单个丙氨酸取代显著降低了肽与CXCR4的结合。相反，Cys-11处的丙氨酸或苯丙氨酸取代导致肽对CXCR4的亲和力显著增强。最后，我们表明V1肽可抑制CXCR4(+) T细胞系中的HIV-1复制。这些研究为V1肽的结构 - 功能关系提供了新的见解，并证明该肽可能是开发治疗药物的先导物。
