Conformational Study of Polypeptide Chains Grafted on the Surface of Polylactide Latex Particle

Tanimoto, Satoshi; Iwata, Toshiya; Yamaoka, H.; Yamada, Masahiro; Kobori, Kana

doi:10.1155/2009/196950

Cited by 3 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the peptide nanoparticle population is a minor component, we neglected its influence on the ζ-potential, and only the micelle population was taken into account. As illustrated in Figure , ζ-potential values lie between 52 and 64 mV and are comparable to values obtained for a saturated polylysine surface (60−80 mV) . Aggregation of the amphiphiles into micelles governs the surface charge and likely limits the aggregation number and dissociation of the lysine counterions.…”

Section: Resultssupporting

confidence: 68%

From Fibers to Micelles Using Point-Mutated Amphiphilic Peptides

et al. 2011

View full text Add to dashboard Cite

Biocompatible, self-assembled nanostructures are attracting ever more attention, in particular in aqueous media for biomedical applications. Here, we present the successful, solid-phase peptide synthesis (SPPS) and characterization of short amino acid sequences with amphiphilic character with the aim of gaining insight into their self-assembled, supramolecular structures. The peptide design includes three parts: (a) a charged lysine part, (b) an acetylated lysine part, and (c) a constant hydrophobic rodlike helix, based on gramicidin A (gA). By stepwise replacement of free lysine (K) with acetylated lysine (X) we generated a library of a total of 10 peptides, Ac-X(8)-gA and K(m)X(8-m)-gA (m ranging from 0 to 8). By using point mutations, we adjusted the degree of acetylation (DA) and thus the overall amphiphilicity of the peptides, which led to a change in the secondary structure in the aqueous environment from a β-sheet to an α-helix. This transition generated a significant change in the morphology of the self-assembled structures from fibers to micelles. Two different regions were observed for the conformation of the hydrophilic part of the peptide: one region, a β-sheet-like secondary structure, inducing fiber formation (high DA), the other an α-helical-like secondary structure, generating micelle formation (moderate and low DA). The micellar structures depended on the degree of acetylation, which influenced their critical micelle concentration (cmc). These morphology regions were determined by a combination of circular dichroism, dynamic light scattering, surface tension, and transmission electron microscopy, which allowed us to correlate the generated supramolecular architectures with the fine changes obtained by means of the point mutation strategy.

show abstract

Section: Resultssupporting

confidence: 68%

From Fibers to Micelles Using Point-Mutated Amphiphilic Peptides

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The degeneracy of the alternate R, S and alternate S, R form implies their equal population. This very well explains the recent experimental observation that PLA homopolymer exhibit no CD signal in the wavelength range from 190 to 250 nm [66]. A molecular view of polymethylglycolide and polyphenylmethylglycolide in R, S form shown in Figure 2 is similar in appearance to the 2 7 ribbon structure reported in poly ∆Leu peptides ith ∆Leu residues being in a ternate Z, E or E, Z forms w l O O   Å).…”

supporting

confidence: 82%

Conformational behavior of stereo regular substituted polyglycolides is side chain dependent

Nandel¹,

Garla²

2011

JBPC

View full text Add to dashboard Cite

Substituted polyglycolides having two asymmetric centers are attractive alternatives to materials derived from petroleum because of their biocompatibility and biodegradability. The conformational behavior of various substituted polyglycolides has been investigated by both quantum mechanical and molecular dynamics approaches. Polymethylglycolide (polylactide) and polyphenylmethylglycolide in RS or SR forms are predicted to adopt 27 ribbon type structures with φ, ψ values of ±30, ±50 or +30 or +50 respectively stabilised by carbonyl-carbonyl interactions. Isopropylglycolide and isobutyl-glycolide having branching at β & γ positions respectively in their side chains can be realized in all SS form with φ, ψ values lying in right handed helical region. In addition to carbonyl-carbonyl interactions, the hydrophobic interactions between the side chains in isopropylgly-colide the C-H-O interactions also contributes to the stability. With cyclic side chains directly attached to Cα of backbone, polyphenylglycolide (polymandelide) and polycyclohexylglycolide are found to adopt left handed helical structure without hydrogen bonds in RR form, stabilised by stacking interactions and hydrophobic interactions respectively. In all the forms of polyphenylglycolide & polycyclohexylglycolide, the cyclic side chains are found to be locked into unfavourable gauche plus conformation. The stability of substituted polyglycolides has been analyzed in terms of various interactions. The carbonyl-carbonyl interactions in all the conformations of all forms of substituted polyglycolides are found to be of highly shielded parallel motif with only one short carbon-oxygen interaction. Simulation studies of substituted polyglycolides in water give a good insight of the approach of water molecules to the backbone

show abstract