Quantitative analysis of complex amino acids and RGD peptides by X‐ray photoelectron spectroscopy (XPS)

Abstract

Quantitative analysis of complex amino acids and RGD peptides by X-ray photoelectron spectroscopy (XPS). Surface and Interface Analysis, 45 (8). 1238 -1246 . ISSN 0142-2421 https://doi.org/10.1002/sia.5261 eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. 1 Quantitative Analysis of Complex Amino Acids and RGD Peptides by X-ray Photoelectron Spectroscopy (XPS)Joanna

Polypyrrole-Supported Membrane Proteins for Bio-Inspired Ion Channels

“…The first one involves not only the sulfate groups of SDS but also the C=O from the peptide bond. 37,38 Accordingly, the C/O 531.3 and N/O 531.3 ratios are 1.8 and 0.1, respectively, which are lower than in control PNMPy.…”

“…N-substituted PPy derivatives typically undergo an oxidation process), and the C-N, C-NH 3 + and C=O from peptide bonds (286.3 eV) in the protein. 37,38 respectively. 34,39 The ratio 1.0/(6.9+1.0) = 0.13 represents the fraction of charged nitrogen, which can be associated to the doping level of the electropolymerized material (Supporting Information).…”

“…Furthermore, the absence of a peak at around 401.5 eV reflects that the amount of positively charged residues in Omp2a is very low. 37,38 Thus, Arg and Lys are essentially present in the composite as uncharged species, photoemitting at the same region that amides in high resolution N1s spectra.…”

Electroactive polymer–peptide conjugates for adhesive biointerfaces

“…The high resolution N1s spectrum shows a peak centered at 400.3 eV, which seems to include both the guanidinium (400.1 eV) and the backbone amide (400.6 eV) signals identified for the RGD peptide sequence. 33 The peak at 402.0 eV, which was also detected in PEDOT samples, has been attributed to impurities of the substrate. 23 The O1s signal consists of three components, with the most intense one at 533.3 eV corresponding to the C-O-C bond in the ethylene bridge of PEDOT.…”

“…Deconvolution of the C1s peak led to five Gaussian curves that has been attributed to saturated and conjugated C-C (284.5 eV) and C=C-O (286.4 eV) bonds of PEDOT chains, 30,31 the C=O of amide (288.3 eV), 32,33 the C-N bonds of guanidinium group in Arg (289.6 eV) 33 and the C-F bonds of residual TFA molecules (292.2 eV) 33 arising from the deprotection step in the synthesis ( Figure 2). The high resolution N1s spectrum shows a peak centered at 400.3 eV, which seems to include both the guanidinium (400.1 eV) and the backbone amide (400.6 eV) signals identified for the RGD peptide sequence.…”