05 Feb Software assisted Analysis for peptide catabolism
16th Iberian Peptide Meeting (16EPI) / 4th Chemical Biology Group Meeting, Barcelona. 5-8 February 2018
Anna Escolaa,b, Antoni Rieraa,b, Ismael Zamora c,d, Tatiana Radchenko c,d
Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain; bDepartament de Química Inorgànica i Orgànica, Universitat de Barcelona, Barcelona, Spain;cPompeu Fabra University, Barcelona, Spain; dLead Molecular Design, S.L., Sant Cugat de Valles, Spain email: tatiana.radchenko01@estudant.upf.edu
Interest in using peptide molecules as therapeutic agents due to high selectivity and efficacy is increasing within the pharmaceutical industry. However, most peptide-derived drugs cannot be administered orally because of low bioavailability and instability in the gastrointestinal tract due to protease activity. Therefore, structural modifications peptides are required to improve their stability. For this purpose, several in-silico software tools have been developed such as PeptideCutter or PoPS, which aim to predict peptide cleavage sites for different proteases. Moreover, several databases exist where this information is collected and stored from public sources such as MEROPS and ExPASy ENZYME databases. These tools can help design a peptide drug with increased stability against proteolysis, though they are limited to natural amino acids or cannot process cyclic peptides, for example. We worked to develop a new methodology to analyze peptide structure and amide bond metabolic stability based on the peptide structure (linear/cyclic, natural/unnatural amino acids). This approach used liquid chromatography / high resolution, mass spectrometry to obtain the analytical data from in vitro incubations. We collected experimental data for a set of seven peptide drugs (somatostatin and analogues) incubated with serum. Mass spectrometry data was analyzed to find metabolites and determine their structures, then all the results were stored in a chemically aware manner, which allows us to compute the peptide bond susceptibility by using a frequency analysis of the metabolic-liable bonds. We analysed peptide half-life and compared it to the data in the literature. It was seen that some of the applied chemical modifications were prolonging half-life of the somatostatin analogues. In total 17 metabolites were found from the various peptides. The most frequent observed cleavage sites agreed with those reported in the literature in the linear part of somatostatin. The main advantages of the developed approach are the abilities to elucidate metabolite structure of cyclic peptides and those containing unnatural amino acids, store processed information in a searchable format within a database leading to frequency analysis of the labile sites for the analyzed peptides. The presented algorithm may be useful to optimize peptide drug properties with regards to cleavage sites, stability, metabolism and degradation products in drug discovery.
References
1. Software-aided approach to investigate peptide structure and metabolic susceptibility of amide bonds in peptide drugs based on high resolution mass spectrometry; Radchenko T., Brink A., Siegrist Y., Kochansky C., Bateman A., Fontaine F., Morettoni L., Zamora I.; PlosOne, 2017.
poster_TR_2018_EPS_AR (1) (1)