Structure-guided engineering of tick evasins for targeting chemokines in inflammatory diseases

Ram Prasad Bhusal; Pramod Aryal; Shankar Raj Devkota; Rina Pokhrel; Menachem J Gunzburg; Simon R Foster; Herman D Lim; Richard J Payne; Matthew C J Wilce; Martin J Stone

doi:10.1073/pnas.2122105119

Structure-guided engineering of tick evasins for targeting chemokines in inflammatory diseases

Proc Natl Acad Sci U S A. 2022 Mar 1;119(9):e2122105119. doi: 10.1073/pnas.2122105119.

Authors

Ram Prasad Bhusal^{1

2}, Pramod Aryal^{3

2}, Shankar Raj Devkota^{3

2}, Rina Pokhrel^{3

2}, Menachem J Gunzburg⁴, Simon R Foster^{3

2

5}, Herman D Lim^{3

2}, Richard J Payne⁶, Matthew C J Wilce^{3

2}, Martin J Stone^{1

2}

Affiliations

¹ Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; ram.bhusal@monash.edu martin.stone@monash.edu.
² Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia.
³ Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.
⁴ Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia.
⁵ QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia.
⁶ School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.

Abstract

As natural chemokine inhibitors, evasin proteins produced in tick saliva are potential therapeutic agents for numerous inflammatory diseases. Engineering evasins to block the desired chemokines and avoid off-target side effects requires structural understanding of their target selectivity. Structures of the class A evasin EVA-P974 bound to human CC chemokine ligands 7 and 17 (CCL7 and CCL17) and to a CCL8-CCL7 chimera reveal that the specificity of class A evasins for chemokines of the CC subfamily is defined by conserved, rigid backbone-backbone interactions, whereas the preference for a subset of CC chemokines is controlled by side-chain interactions at four hotspots in flexible structural elements. Hotspot mutations alter target preference, enabling inhibition of selected chemokines. The structure of an engineered EVA-P974 bound to CCL2 reveals an underlying molecular mechanism of EVA-P974 target preference. These results provide a structure-based framework for engineering evasins as targeted antiinflammatory therapeutics.

Keywords: chemokines; inflammatory diseases; protein engineering; tick evasins.

MeSH terms

Animals
Arthropod Proteins / chemistry*
Arthropod Proteins / metabolism
Chemokines / metabolism*
Inflammation / metabolism*
Protein Binding
Protein Conformation
Protein Engineering*
Receptors, Chemokine / metabolism
Ticks / metabolism*

Substances

Arthropod Proteins
Chemokines
Receptors, Chemokine