Peptide layers

Enzymatic Degradation of H214/03. The degradation experiments were carried out with molecular mixtures of H214/03 or LVP and MO. These were obtained from mixtures of the peptide and MO dissolved in 99.5% ethanol, from which the ethanol was evaporated under reduced pressure at room temperature for about two days. Appropriate amounts of melted mixtures were then weighed in small Erlenmeyer flasks. Care was taken to insure that the bottom of each flask was covered with the mixture, which was then left to freeze. In this way the area and the thickness of the lipid/peptide layer was comparable in the flasks. Typically five flasks were used in each experiment... 

Total thickness d of a sheet (A) thickness cIa of the carbohydrate layer (O) thickness di3 of the peptide layer (6). 

It is known that not all reactions proceed in the same manner on all adsorbent layers because the material in the layer may promote or retard the reaction. Thus, Ganshirt [209] was able to show that caffeine and codeine phosphate could be detected on aluminium oxide by chlorination and treatment with benzidine, but that there was no reaction with the same reagent on silica gel. Again the detection of amino acids and peptides by ninhydrin is more sensitive on pure cellulose than it is on layers containing fluorescence indicators [210]. The NBP reagent (. v.) cannot be employed on Nano-Sil-Ci8-100-UV2S4 plates because the whole of the plate background becomes colored. 

Differences in the materials employed for the layers can also become evident when chemical reactions are performed on them. Thus, Macherey-Nagel report that the detection of amino acids and peptides by reaction with ninhydrin is less sensitive on layers containing luminescent or phosphorescent indicators compared to adsorbents which do not contain any indicator [7]. 

Figure 6.7 Formation of cross-linkage between individual peptide chains in the peptidoglycan layer of S. aureus.

Imanishi, Y. Synthese, Conformation, and Reactions of Cyclic Peptides. Vol. 20, pp. 1 — 77. Inagaki, H. Polymer Separation and Characterization by Thin-Layer Chromatography. Vol. 24, pp. 189-237. 

Inspired by the elastin-based side-chain polymers, Lemieux et al. prepared elastin-based stimulus-responsive gold nanoparticles. To this end, they capped gold particles with a layer of a single repeat of thiol-functionalized VPGVG peptides (Fig. 17a). These nanoparticles showed LCST behavior, which was modulated by varying the pH of the solution [131]. 

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