Comparative molecular dynamics study of the structural properties of melittin in water and trifluoroethanol/water

Melittin Tryptophan Substitution with a Fluorescent Amino Acid Reveals the Structural Basis of Selective Antitumor Effect and Subcellular Localization in Tumor Cells

“…In this respect, the lower ellipticity values found at 222 and 208 nm for MEL FL relative to melittin reflect a ~50% loss of ellipticity signal, suggesting that Dap AMCA substitution at W19 residue induces either a regional conformation disorder, or signal interference from the isopeptide bond and chromophore on the side-chain of Dap AMCA in the melittin. In order to capture the peptide folding behaviors and obtain further insight into changes in the secondary structure of two peptides, we carried out all-atom molecular dynamics (MD) simulations of melittin and MEL FL using the GROMACS software package (https://www.gromacs.org, accessed on 9 April 2021) [19,20]. The input structures were adapted from the crystal structure of the melittin monomer from the PDB bank (PDB code: 2MLT).…”

De novo design of short antimicrobial lipopeptides

“…The identity of each lipopeptide was confirmed by ESI-MS, in which the calculated molecular weight corresponds to the observed molecular weight + H + , indicating that the synthesis was performed correctly (Table I). Circular dichroism analysis carried out by diluting the lipopeptides in 30% trifuloroethanol (TFE) to stabilize secondary structures formation having a high dipole moment (Naumenkova et al 2010, Tiburu et al 2017) indicated that, in general, the designed lipopeptides showed a probable random coil secondary structure according to the CD spectra, with two negative bands at 200 nm and 220 nm (Fig. 2).…”

Assessment of the Role of 2,2,2-Trifluoroethanol Solvent Dynamics in Inducing Conformational Transitions in Melittin: An Approach with Solvent 19F Low-Field NMR Relaxation and Overhauser Dynamic Nuclear Polarization Studies

“…22 It is an amphiphilic peptide containing 26 amino acid residues, with broad-spectrum biological activities. 23 It is also a major component of honey bee Apis mellifera venom 24 and is known to have potential antimicrobial properties. 22 MLT exists as a random coil (unordered) monomer in water at a low pH (acidic pH, i.e., 2−5) or in solutions of low ionic strength at a low peptide concentration.…”

“…30,31 Molecular dynamics (MD) simulation studies have also been performed, revealing the helical conformation of MLT in alcohol to be more stable than in aqueous solution. 23,32 In the present study, we aim to benchmark the low-field 19 F relaxation and 19 F Overhauser dynamic nuclear polarization (ODNP) by analyzing the solvent dynamics of TFE in the presence of the structural transitions of a model aqueous MLT solution at pH 7.4, with TFE as a cosolvent. Further, these two experimental approaches have been employed to elucidate TFE dynamics in a nonbuffered solution of MLT at pH 2.8 for the first time.…”

“…MLT is known for unique structural transitions from a random form to a fully folded tertiary structure, making it a viable model for protein folding and aggregation studies . It is an amphiphilic peptide containing 26 amino acid residues, with broad-spectrum biological activities . It is also a major component of honey bee Apis mellifera venom and is known to have potential antimicrobial properties .…”