Peptide Assisted Design of Peptoid Sequences One Small Step in Structure and Distinct Leaps in Functions

Using peptide sequences for the design of functional peptoids is demonstrated for a peptide based formulation additive that was specifically tailored to solubilize the photosensitizer meta tetra hydroxyphenyl chlorin. A set of peptoid block poly ethylene glycol solubilizers with systematic sequence variations are synthesized to reveal contributions of side chain sequence and backbone functionalities on drug hosting and release properties. The drug payload sensitively depends on the side chain patterns, and the best performing peptoid sequence reaches 3 times higher capacity than the corresponding peptide. The peptoid backbone not only acts as a neutral scaffold but also impacts the drug release kinetics compared to the analogues peptide, by reducing the capability to assist drug transfer to blood plasma protein model

Matching 4.7-Å XRD Spacing in Amelogenin Nanoribbons and Enamel Matrix

The recent discovery of conditions that induce nanoribbon structures of amelogenin protein in vitro raises questions about their role in enamel formation. Nanoribbons of recombinant human full-length amelogenin (rH174) are about 17 nm wide and self-align into parallel bundles; thus, they could act as templates for crystallization of nanofibrous apatite comprising dental enamel. Here we analyzed the secondary structures of nanoribbon amelogenin by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) and tested if the structural motif matches previous data on the organic matrix of enamel. XRD analysis showed that a peak corresponding to 4.7 Å is present in nanoribbons of amelogenin. In addition, FTIR analysis showed that amelogenin in the form of nanoribbons was comprised of β-sheets by up to 75%, while amelogenin nanospheres had predominantly random-coil structure. The observation of a 4.7-Å XRD spacing confirms the presence of β-sheets and illustrates structural parallels between the in vitro assemblies and structural motifs in developing enamel

Log D versus HPLC derived hydrophobicity: The development of predictive tools to aid in the rational design of bioactive peptoids

Hydrophobicity has proven to be an extremely useful parameter in small molecule drug discovery programmes given that it can be used as a predictive tool to enable rational design. For larger molecules, including peptoids, where folding is possible, the situation is more complicated and the average hydrophobicity (as determined by RP-HPLC retention time) may not always provide an effective predictive tool for rational design. Herein, we report the first ever application of partitioning experiments to determine the log D values for a series of peptoids. By comparing log D and average hydrophobicities we highlight the potential advantage of employing the former as a predictive tool in the rational design of biologically active peptoids. This article is protected by copyright