Evaluating binding and interaction of selected pesticides with serum albumin proteins by Raman, 1H NMR, mass spectrometry and molecular dynamics simulation

Abstract

Addressing the acute pesticide poisoning and toxicity to humans, is a global challenge of top priority. Serum albumin is the most abundant plasma protein, capable of binding with herbicide and pesticide residues. This study reports multifaceted approaches for in-depth and robust investigation of the molecular interactions of selected pesticides, including propanil (PPL), bromoxynil (BXL), metolachlor (MLR) and glyphosate (GPE) with bovine serum albumin (BSA) proteins using experimental (Raman and FTIR spectroscopy, native mass spectrometry and high field ¹H NMR), molecular dynamics (MD) simulation and principal component analysis (PCA). The binding of pesticides with BSA resulted in BSA amide I and amide II Raman spectral shifts. PCA of Raman spectra of serum-pesticide complexes showed the grouping of pesticides on the score plot based on the similarities and differences in pesticides’ chemical structures. Native mass spectrometry results revealed strong adduct formation of the pesticides with the protein. The observed changes in chemical shifts, peak broadening or peak disappearance of characteristic proton signals of the pesticides, indicated altered chemical environments due to binding BSA-pesticides interactions. The results of MD simulation conducted for over 500 ns revealed strong pesticides interaction with LEU197, LEU218, LEU237, TRP213, SER286 and ILE289 residues to the site I of BSA. Free energy landscapes provided insights into the conformational changes in BSA on the binding of pesticides. Overall, the experimental and computational results are in consonant and indicate the binding of pesticides into the site I and site II (sub-domain IIA) of the BSA via hydrogen bonding, non-covalent and hydrophobic interactions.

Communicated by Ramaswamy H. Sarma

Keywords:

• Serum albumin
• propanil
• bromoxynil
• metolachlor
• glyphosate
• pesticide
• molecular docking
• molecular dynamics simulation
• Raman spectroscopy
• mass-spectrometry
• nuclear magnetic resonance

Acknowledgement

The financial support for Brinkley Bolton and Bailey Dassow from Chemistry Scholar Program, Georgia College & State University is acknowledged. The First-Year and Sophomore Scholar Program at the Office of Undergraduate Research, KSU, is acknowledged for the stipend and funding support for Noam Lewit. The Mentor Protégé Program at the College of Science and Mathematics, KSU, partially supports this project. K. Bwambok acknowledges Ball State University Provost start-up funding for supporting some of this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.