Swapping N-terminal regions among tick evasins reveals cooperative interactions influencing chemokine binding and selectivity

Aryal, Pramod; Devkota, Shankar Raj; Jeevarajah, Devadharshini; Law, Ruby H. P.; Payne, Richard J.; Bhusal, Ram Prasad; Stone, Martin J.

doi:10.1016/j.jbc.2022.102382

Cited by 5 publications

(7 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Considering that these structural elements are adjacent in evasin three-dimensional structures 14 , they have the potential to form a fifth disulfide bond. Moreover, as the N-terminal region was known to be important for chemokine recognition 11 , 15 , we envisaged that this structural feature would likely influence function. In addition to ten conserved Cys residues, these evasin-like sequences contain several other features consistent with them being functional evasins 14 , 16 , including secretion signal sequences, two Gly residues conserved amongst class A1 evasins, several potential N-linked glycosylation sites, and potential Tyr sulfation sites within their N-terminal sequences (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Although statistical comparison of affinities is not possible because only a single K d value was reported 17 , some apparent affinity differences could potentially be attributed to differences in expression systems, post-translational modifications, purity, biophysical methods and/or solution conditions for binding experiments. Whereas EVA-4 is also a broad-spectrum binder to CC chemokines 11 , EVA-4 and EVA-A exhibit quite distinct chemokine affinity profiles (Supplementary Fig. 7 ).…”

Section: Resultsmentioning

confidence: 99%

“…However, each evasin targets a unique spectrum of chemokines within its cognate family. For example, the class A evasins EVA-1 and EVA-4 bind to four and 17 human CC chemokines, respectively 11 , whereas the class B evasin EVA-3 binds to six CXC chemokines 12 . Evasins from both families have exhibited anti-inflammatory activity in animal models of inflammatory diseases 10 .…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Engineering broad-spectrum inhibitors of inflammatory chemokines from subclass A3 tick evasins

et al. 2023

Self Cite

View full text Add to dashboard Cite

Chemokines are key regulators of leukocyte trafficking and attractive targets for anti-inflammatory therapy. Evasins are chemokine-binding proteins from tick saliva, whose application as anti-inflammatory therapeutics will require manipulation of their chemokine target selectivity. Here we describe subclass A3 evasins, which are unique to the tick genus Amblyomma and distinguished from “classical” class A1 evasins by an additional disulfide bond near the chemokine recognition interface. The A3 evasin EVA-AAM1001 (EVA-A) bound to CC chemokines and inhibited their receptor activation. Unlike A1 evasins, EVA-A was not highly dependent on N- and C-terminal regions to differentiate chemokine targets. Structures of chemokine-bound EVA-A revealed a deep hydrophobic pocket, unique to A3 evasins, that interacts with the residue immediately following the CC motif of the chemokine. Mutations to this pocket altered the chemokine selectivity of EVA-A. Thus, class A3 evasins provide a suitable platform for engineering proteins with applications in research, diagnosis or anti-inflammatory therapy.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Engineering broad-spectrum inhibitors of inflammatory chemokines from subclass A3 tick evasins

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, similar truncations of the class A1 evasin EVA‐P974 resulted in a loss of binding to most target chemokines (Bhusal et al, 2022 ). The importance of these regions in class A1 evasins is supported by studies of various chimeras (Aryal et al, 2022 ; Eaton et al, 2018 ), point mutants (Bhusal et al, 2022 ; Bonvin et al, 2014 ; Dias et al, 2009 ), and post‐translationally modified evasins (Franck et al, 2020 ). Thus, it appears that class A3 evasins have evolved from class A1 evasins such that they no longer utilize their N‐ and C‐terminal regions but can still bind with high affinity to numerous CC chemokines.…”

Section: Discussionmentioning

confidence: 97%

Structural basis of chemokine recognition by the class A3 tick evasin EVA‐ACA1001

Devkota,

Aryal,

Wilce

et al. 2024

Protein Science

Self Cite

View full text Add to dashboard Cite

Ticks produce chemokine‐binding proteins, known as evasins, in their saliva to subvert the host's immune response. Evasins bind to chemokines and thereby inhibit the activation of their cognate chemokine receptors, thus suppressing leukocyte recruitment and inflammation. We recently described subclass A3 evasins, which, like other class A evasins, exclusively target CC chemokines but appear to use a different binding site architecture to control target selectivity among CC chemokines. We now describe the structural basis of chemokine recognition by the class A3 evasin EVA‐ACA1001. EVA‐ACA1001 binds to almost all human CC chemokines and inhibits receptor activation. Truncation mutants of EVA‐ACA1001 showed that, unlike class A1 evasins, both the N‐ and C‐termini of EVA‐ACA1001 play minimal roles in chemokine binding. To understand the structural basis of its broad chemokine recognition, we determined the crystal structure of EVA‐ACA1001 in complex with the human chemokine CCL16. EVA‐ACA1001 forms backbone‐backbone interactions with the CC motif of CCL16, a conserved feature of all class A evasin‐chemokine complexes. A hydrophobic pocket in EVA‐ACA1001, formed by several aromatic side chains and the unique disulfide bond of class A3 evasins, accommodates the residue immediately following the CC motif (the “CC + 1 residue”) of CCL16. This interaction is shared with EVA‐AAM1001, the only other class A3 evasins characterized to date, suggesting it may represent a common mechanism that accounts for the broad recognition of CC chemokines by class A3 evasins.

show abstract

“…Considering that these structural elements are adjacent in evasin three-dimensional structures 12 , they have the potential to form a fifth disulfide bond. Moreover, as the N-terminal region was known to be important for chemokine recognition 13,14 , we envisaged that this new structural feature would likely influence function. In addition to ten conserved Cys residues, these evasin-like sequences contain several other features consistent with them being functional evasins 12,15 , including secretion signal sequences, two Gly residues conserved amongst class A1 evasins, several potential N-linked glycosylation sites, and potential Tyr sulfation sites within their Nterminal sequences (Fig.…”

Section: Discovery and Phylogeny Of Class A3 Evasinsmentioning

confidence: 99%

Engineering Broad-spectrum Inhibitors of Inflammatory Chemokines from a New Family of Tick Evasins

Devkota

Aryal

Jiao

et al. 2023

Preprint

View full text Add to dashboard Cite

Chemokines, the key regulators of leukocyte trafficking, are attractive targets for anti-inflammatory therapy. Evasins are anti-inflammatory, chemokine-binding proteins found in tick saliva, with important therapeutic potential. However, therapeutic application of evasins will require manipulation of their chemokine target selectivity. Here we describe a new family of evasins, class A3 evasins, that is unique to the tick genus Amblyomma and distinguished from “classical” class A1 evasins by an additional disulfide-bonded pair of cysteine residues near the chemokine recognition interface. The class A3 evasin EVA-AAM1001 (EVA-A) bound to CC chemokines and inhibited their receptor activation. However, unlike class A1 evasins, EVA-A did not utilise N- and C-terminal regions to differentiate chemokine targets. Instead, structures of EVA-A bound to four chemokines revealed a deep hydrophobic pocket, unique to class A3 evasins, that interacts with the residue immediately following the CC motif of the chemokine (the “CC+1” residue). The preference of EVA-A for chemokines with aliphatic CC+1 residues results from negative selection against binding of aromatic CC+1 residues into this pocket. Consequently, mutations to alleviate this negative selection yielded broad-spectrum chemokine inhibitors. This study illustrates that class A3 evasins are an excellent platform for engineering proteins with targeted chemokine binding selectivity for applications in research, diagnosis or anti-inflammatory therapy.

show abstract

Swapping N-terminal regions among tick evasins reveals cooperative interactions influencing chemokine binding and selectivity

Cited by 5 publications

References 32 publications

Engineering broad-spectrum inhibitors of inflammatory chemokines from subclass A3 tick evasins

Engineering broad-spectrum inhibitors of inflammatory chemokines from subclass A3 tick evasins

Structural basis of chemokine recognition by the class A3 tick evasin EVA‐ACA1001

Engineering Broad-spectrum Inhibitors of Inflammatory Chemokines from a New Family of Tick Evasins

Contact Info

Product

Resources

About