title: Findings on the interaction of the antimicrobial peptide cecropin-melittin with a gold surface from molecular dynamics studies.
abstract: The immobilization of gold nanoparticles (AuNPs) with antimicrobial peptides (AMPs) is a new and promising way to enhance both the activity and targeting capabilities of AMPs. However, a full understanding of the adsorption process underlying these materials is still lacking. Cecropin-melittin is a peptide with a broad antimicrobial activity while displaying low hemolytic properties, whose conjugation with AuNPs has not been studied before. In this context, we report the investigation of the adsorption process of the cecropin-melittin peptide, with (CM-SH) and without (CM) cysteine at its C-terminus, onto a gold surface based on all-atom MD simulations. Our results show that the way the peptides approach the surface dictates the final conformation and the time required to achieve it in both CM-SH and CM cases. Most important, it is demonstrated that the presence of cysteine promotes a faster conformational stabilization during the lockdown regime of the CM-SH peptide, noticeably affecting this by acting as a preferential anchoring point. This investigation represents a first step in rationalizing, with atomistic detail, some experimentally observed features of CM-SH and CM immobilized gold nanoparticles.
authors.affiliation: Department of Chemical Engineering, CIEPQPF, University of Coimbra, 3030-790, Coimbra, Portugal. aff@eq.uc.pt.
authors.forename: André F
authors.initials: AF
authors.lastname: Ferreira
authors.affiliation: CNC-Center for Neurosciences and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.|Biocant, Biotechnology Innovation Center, 3060-197, Cantanhede, Portugal.
authors.forename: Akhilesh
authors.initials: A
authors.lastname: Rai
authors.affiliation: CNC-Center for Neurosciences and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.|Biocant, Biotechnology Innovation Center, 3060-197, Cantanhede, Portugal.
authors.forename: Lino
authors.initials: L
authors.lastname: Ferreira
authors.affiliation: Department of Chemical Engineering, CIEPQPF, University of Coimbra, 3030-790, Coimbra, Portugal.
authors.forename: Pedro N
authors.initials: PN
authors.lastname: Simões
mesh_terms: D000327:Adsorption; D000595:Amino Acid Sequence; D054807:Cecropins / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008555:Melitten / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D011487:Protein Conformation; D013499:Surface Properties
chemical_list: D054807:Cecropins; D008555:Melitten; D006046:Gold
keywords: Antimicrobial peptide; Cecropin melittin; Cysteine; Gold surface; Molecular dynamics