Redox investigation of L-A9 peptide and evaluation of its binding with double stranded DNA - Research report

Sep 30, 2026

Upload by Liam

L-A9 is a biomedical short peptide synthesized via manual solid phase synthesis, with its redox behavior characterized using voltammetric techniques. The oxidation peak exhibits strong pH dependence, indicating a 1 e and 2 proton transfer process, and an electroanalytical method is reported with a detection limit of 1.17 × 10−7 M. Redox modulation is used to evaluate binding to double-stranded DNA, yielding reported binding constants, supported by spectroscopic, SEM, and molecular docking evidence for interactions through hydrogen bonding and electrostatic contacts.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

Abstract

Peptide synthesis and redox characterization

pH dependence and electrochemical performance

DNA binding studies and binding constants

Spectroscopic, SEM, and molecular docking support

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Redox investigation of L-A9 peptide and evaluation of its binding with double stranded DNA Preeti Dwivedi1,2, Sudipa Manna1, Drishty Satpati3,5, Amit Das4,5, Suresh Shendage2 & Ashis Kumar Satpati1,5􀀍 L-A9 is one of the important short peptides having biomedical applications in relation to its affinity towards HER2 receptors. The peptide has been synthesised using manual solid phase synthesis protocol and the redox property has been investigated using the voltammetric techniques. The oxidation peak of the peptide has shown strong pH dependency, revealed the 1 e and 2 proton transfer process. Electroanalytical method is developed with limit of detection of 1.17 × 10−7 M. The modulation of the redox property has been monitored to investigate the binding of the peptide with dsDNA, with binding constant of 1.8 × 10⁵ M− 1 . Spectroscopic measurements ofthe peptide revealed the pH dependent electronic transition and the binding constant with dsDNA of 1.4 × 104 M− 1. The needle like assembly of L-A9 peptide has been indicated from the SEM measurements with coil kind of morphology of dsDNA has been observed when the L-A9 peptide and dsDNA interacted with eachother. The electrochemical and spectroscopic investigations indicated that the acidic functional groups of L-A9 interacts with the major groove of dsDNA through the modifications of 3 hydrogen bonds between the strands, whereas the basic functional groups of L-A9 binds externally with dsDNA by formation of bonds with O atoms of the phosphodiester groups, which has been supported from the molecular docking investigations. Keywords L-A9 peptide, Redox property, Spectroscopic investigation, Surface charge, DNA, Binding property The development of peptides-based drugs and pharmaceuticals have made significant progress in last few decades due to the advancement in the synthesis, purification and analytical methods of their characterisation. Additionally, the improvised delivery strategy of the peptide-based drugs overcomes the challenges of the therapeutic usage of peptides. Insulin has been the most popular and important peptide-based drug dominated the market for over 90 years, which is now replaced by the recombinant insulin1,2. Smaller sized drugs have the advantages as it is easy to administer which has enhanced patient compliance and penetration3,4. Additionally, the short peptides are mostly used due to their biological activities in immune reactions, in brain functions, blood pressure normalization and controlling the vascular tone. Short peptides are present in all tissues, and they are usually treated as “fragments” of functional proteins and having complex functions in biological systems5. The short peptides generally considered to have up to 100 amino acids, have the advantage of easy penetration through the cell membranes6. Importantly the short peptides can interact with DNA7–910. The gene expression has strong influence on the controlled combination of DNA-binding proteins, which also has influence of the presence of metals11. Metal ions play important role in modulating the interaction of the peptides with DNA, which influence important biological functions12. Monoclonal antibodies were considered as the potential magic bullet for cancer treatment because of their antigen specific binding to the neoplastic cells. In the view of challenges posed by their high molecular weight, low penetration, risk of allergic reactions and long half-life13, researchers turned to antibody fragments as they retain the specific antigen binding capability while having more tailored half-life and better membrane penetration14. Antibody fragments offers several simultaneous benefits as they can be perfect drug carriers due to their specific antigen binding while it induces tumour cell apoptosis by interfering with signalling and manipulating immune system. More tailored treatment 1Analytical Chemistry

FAQs

How was the L-A9 peptide synthesized and its redox property measured?

L-A9 was synthesized using manual solid phase synthesis, and its redox property was investigated using voltammetric electrochemical techniques.

What does the pH-dependent oxidation peak indicate?

The oxidation peak shows strong pH dependency, revealing a 1 e and 2 proton transfer process.

How was the binding between L-A9 and double-stranded DNA evaluated?

Binding was assessed by monitoring redox modulation and supported by spectroscopic measurements, SEM observations, and molecular docking.

Sep 30, 2026

Upload by Liam