Significant destabilization of human telomeric G-quadruplex upon peptide binding: dramatic effect of flanking bases

Abstract

Human telomere is composed of highly repeated hexanucleotide sequence TTAGGG and a 3′ single-stranded DNA tail. Many telomere G4 topologies characterized at atomic level by X-ray crystallography and NMR studies. Until now, various small ligands developed to interact with G-quadruplex mainly to stabilize the structure and least is known for its destabilization. In this study, we provide the first evidence of human telomeric G4 destabilization upon peptide binding in dilute and cell-mimicking molecular crowing conditions due to the changes in flanking bases of human telomeric sequences. Hence, our findings will open the new ways to target diseases related with increasing the efficiency of DNA replication, transcription or duplex reannealing.

Communicated by Ramaswamy H. Sarma

Keywords:

• G-quadruplex
• G-quadruplex peptide
• UV thermal melting
• fluorescence spectroscopy
• human telomere

Acknowledgments

The timely help from Prof. Shrikant Kukreti and Dr. Anju Singh of Nucleic Acid Research Laboratory, Delhi University is greatly acknowledged.

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

We thank Department of Biotechnology (DBT), Govt of India for research funding to this project (SAN No. 102/IFD/SAN/864/2018-2019)