Enhancing pesticide detection: The role of serine in lipopeptide nanostructures and their self-assembly dynamics

Autor(es)

Gerbelli, Barbara B. ; Sodre, Pedro T. ; Filho, Pedro L. O. ; Coutinho-Neto, Mauricio D. ; Hamley, Ian W. ; Seitsonen, Jani ; Alves, Wendel A.

• Tipo de documento: Artigo Científico
• Fonte: Journal of Colloid and Interface Science; v. 690, p. 14-pg., 2025-07-15.

Resumo

In this research, we studied two novel lipopeptide sequences containing the amino acid serine (SPRWG) with one (compound 1) or two aliphatic tails (compound 2) to optimize the detection capabilities for organophosphate pesticides, specifically glyphosate. The study comprehensively explored how the incorporation of serine influences the physicochemical properties and supramolecular assembly of the lipopeptides, leading to enhanced interactions with glyphosate. Advanced analytical methods were employed to investigate these modifications, including fluorescence spectroscopy, circular dichroism, and small-angle X-ray scattering (SAXS). The results showed that serine significantly reduces the critical aggregation concentration, increases the hydrophilicity of the lipopeptides, and promotes the formation of distinct secondary structures-/3-turns in compound 1 and /3-sheets in compound 2. Moreover, isothermal titration calorimetry (ITC) and molecular dynamics confirmed the improved binding affinity with glyphosate strongly modulated by pH and pesticide load. Compound 1, with one alkyl chain, demonstrated notably higher catalytic activity and sensitivity linked to its pH equilibrium and structural features, marking it as particularly effective for acetylcholinesterase mimicry in pesticide detection. Density functional theory and molecular dynamics calculations showed that, when compared to the PRWG sequence, SPRWG has more unprotonated N-terminal sites due to a lower pKa, more beta-turn-like structures that improve stabilization. Besides promotes more hydrogen bonds between N-(phosphonomethyl)glycine (PNG, commonly known as glyphosate) and aggregates across a wide pH range and P/L; which explains its enhanced reactivity in Ellman's test and better inhibitory effects under the influence of PNG. Our results suggest that serine-functionalized lipopeptides have great potential as biomimetic sensors in environmental monitoring. (AU)

• Processo FAPESP: 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte
• Beneficiário: Adalberto Fazzio
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 22/14753-0 - Tecnologias de biossensores e sistemas de liberação controlada baseadas em microagulhas para diagnóstico e tratamento de doenças
• Beneficiário: Wendel Andrade Alves
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/50867-3 - INCT 2014: Instituto Nacional de Ciência e Tecnologia de Bioanalítica
• Beneficiário: Marco Aurelio Zezzi Arruda
• Modalidade de apoio: Auxílio à Pesquisa - Temático