Structure–Activity Relationship of RGD-Containing Cyclic Octapeptide and αvβ3 Integrin Allows for Rapid Identification of a New Peptide Antagonist

Authors

Aaron Silva, The University of Texas Rio Grande Valley
Wenwu Xiao
Yan Wang
Wei Wang
Heng Wei Chang
James B. Ames
Kit S. Lam
Yonghong Zhang, The University of Texas Rio Grande Valley

Document Type

Article

Publication Date

4-2020

Abstract

The αvβ3 integrin, a receptor for many extracellular matrix proteins with RGD-sequence motif, is involved in multiple physiological processes and highly expressed in tumor cells, therefore making it a target for cancer therapy and tumor imaging. Several RGD-containing cyclic octapeptide (named LXW analogs) were screened as αvβ3 antagonists with dramatically different binding affinity, and their structure–activity relationship (SAR) remains elusive. We performed systematic SAR studies and optimized LXW analogs to improve antagonistic potency. The NMR structure of LXW64 was determined and docked to the integrin. Structural comparison and docking studies suggested that the hydrophobicity and aromaticity of the X7 amino acid are highly important for LXW analogs binding to the integrin, a potential hydrophobic pocket on the integrin surface was proposed to play a role in stabilizing the peptide binding. To develop a cost-efficient and fast screening method, computational docking was performed on LXW analogs and compared with in vitro screening. A consistency within the results of both methods was found, leading to the continuous optimization and testing of LXW mutants via in silico screening. Several new LXW analogs were predicted as the integrin antagonists, one of which—LXZ2—was validated by in vitro examination. Our study provides new insight into the RGD recognition specificity and valuable clues for rational design of novel αvβ3 antagonists.

Comments

Original published version available at https://doi.org/10.3390/ijms21093076

Recommended Citation

Silva, A., Xiao, W., Wang, Y., Wang, W., Chang, H. W., Ames, J. B., Lam, K. S., & Zhang, Y. (2020). Structure–Activity Relationship of RGD-Containing Cyclic Octapeptide and αvβ3 Integrin Allows for Rapid Identification of a New Peptide Antagonist. International Journal of Molecular Sciences, 21(9), 3076. https://doi.org/10.3390/ijms21093076

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

International Journal of Molecular Sciences

DOI

10.3390/ijms21093076