Influence of chirality and sequence in lysine-rich lipopeptide biosurfactants and micellar model colloid systems

• Published in: Nature communications 2024-08, Vol.15 (1), p.6785-13, Article 6785
• Main Authors: Hamley, Ian W., Adak, Anindyasundar, Castelletto, Valeria
• Format: Article
• Language: English
• Subjects: 119/118; 639/301/54/989; 639/301/923/966; 639/638/92/56; 639/925/357/341; Aggregation behavior; Amino Acid Sequence; Biomaterials; Biomedical materials; Biosurfactants; Chirality; Colloids - chemistry; Conformation; Dynamic structural analysis; Electric potential; Electrical conductivity; Electrical resistivity; Form factors; Humanities and Social Sciences; Lipids; Lipopeptides; Lipopeptides - chemistry; Lysine; Lysine - chemistry; Micelles; Molecular dynamics; Molecular Dynamics Simulation; Molecular structure; multidisciplinary; Peptides; Residues; Scattering, Small Angle; Science; Science (multidisciplinary); Self-assembly; Sequences; Small angle X ray scattering; Structure factor; Surface Tension; Surface-Active Agents - chemistry; Tryptophan; Tyrosine; X-Ray Diffraction; X-ray scattering; Zeta potential
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-51234-8

Lipopeptides can self-assemble into diverse nanostructures which can be programmed to incorporate peptide sequences to achieve a remarkable range of bioactivities. Here, the influence of peptide sequence and chirality on micelle structure and interactions is investigated in a series of lipopeptides bearing two lysine or D -lysine residues and tyrosine or tryptophan residues, attached to a hexadecyl lipid chain. All molecules self-assemble into micelles above a critical micelle concentration (CMC). Small-angle x-ray scattering (SAXS) is used to probe micelle shape and structure from the form factor and to probe inter-micellar interactions via analysis of structure factor. The CMC is obtained consistently from surface tension and electrical conductivity measurements. We introduce a method to obtain the zeta potential from the SAXS structure factor which is in good agreement with directly measured values. Atomistic molecular dynamics simulations provide insights into molecular packing and conformation within the lipopeptide micelles which constitute model self-assembling colloidal systems and biomaterials. Lipopeptides show great potential as green surfactants but the aggregation behavior of designed lipopeptides bearing linear peptide sequences remains understudied. Here, the authors examine the micellization of chiral lipopeptides bearing lysine-rich tripeptide sequences and investigate structural effects as well as the surface tension and electrical conductivity.