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Hypothesis: Lipopeptides synthesized from the Nucleolar Targeting Peptide (NrTP6) with one, two or four dodecanoic fatty acid (FA) chains, display large head to tail volumes, which together with the number of lipid chains per molecule, impacts their self-assembly behavior. In phosphate buffer (PB), peptide to peptide interactions are triggered by the presence of phosphate ions that act as ionic crosslinkers, affecting the organization of the lipid assemblies., Experimental: The NrTP6 lipopeptides were synthesized by the solid phase peptide synthesis technique. The critical micellar concentration (CMC) of the lipopeptides was determined in water and PB by pyrene fluorescence. The size and morphology of lipopeptide assemblies were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Circular dichroism (CD) was used to study the secondary structures of the lipopeptide assemblies., Results: For NrTP6 lipopeptides with two and four lipid chains, CMCs in water are larger than in PB. TEM images of the lipopeptide assemblies show different morphologies including fibers, rods, and spheres depending on the number of lipid chains, concentration and whether they are assembled in water or PB. CD spectroscopy shows that the peptide conformation, either random or beta, correlates with the morphology of the assemblies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)