6stk
From Proteopedia
Crystal structure of the CC-chemokine 5 (CCL5) E66S mutation
Structural highlights
Function[CCL5_HUMAN] Chemoattractant for blood monocytes, memory T-helper cells and eosinophils. Causes the release of histamine from basophils and activates eosinophils. Binds to CCR1, CCR3, CCR4 and CCR5. One of the major HIV-suppressive factors produced by CD8+ T-cells. Recombinant RANTES protein induces a dose-dependent inhibition of different strains of HIV-1, HIV-2, and simian immunodeficiency virus (SIV). The processed form RANTES(3-68) acts as a natural chemotaxis inhibitor and is a more potent inhibitor of HIV-1-infection. The second processed form RANTES(4-68) exhibits reduced chemotactic and HIV-suppressive activity compared with RANTES(1-68) and RANTES(3-68) and is generated by an unidentified enzyme associated with monocytes and neutrophils.[1] [2] [3] [4] [5] Publication Abstract from PubMedTicks, as blood sucking parasites, have developed a complex strategy to evade and suppress host immune responses during feeding. The crucial part of this strategy is expression of a broad family of salivary proteins, called Evasins, to neutralize chemokines responsible for cell trafficking and recruitment. However, structural information about Evasins is still scarce and little is known about the structural determinants of their binding mechanism to chemokines. Here, we studied the structurally uncharacterized Evasin-4, which neutralizes a broad range of CC-motif chemokines, including the chemokine CC-motif ligand 5 (CCL5) involved in atherogenesis. Crystal structures of Evasin-4 and E66S CCL5-an obligatory dimeric variant of CCL5-were determined to a resolution of 1.3-1.8 A. The Evasin-4 crystal structure revealed an L-shaped architecture formed by an N- and C-terminal subdomain consisting of eight beta-strands and an alpha-helix that adopts a substantially different position compared to closely related Evasin-1. Further investigation into E66S CCL5/Evasin-4 complex formation with NMR spectroscopy showed that residues of the N-terminus are involved in binding to CCL5. The peptide derived from the N-terminal region of Evasin-4 possessed nM affinity to CCL5 and inhibited CCL5 activity in monocyte migration assays. This suggests that Evasin-4 derivatives could be used as starting point for the development of anti-inflammatory drugs. Structural characterization of anti-CCL5 activity of the tick salivary protein Evasin-4.,Denisov SS, Ramirez-Escudero M, Heinzmann ACA, Ippel JH, Dawson PE, Koenen RR, Hackeng TM, Janssen BJC, Dijkgraaf I J Biol Chem. 2020 Aug 14. pii: RA120.013891. doi: 10.1074/jbc.RA120.013891. PMID:32817341[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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