Mass spectrometric quantification of the antimicrobial peptide Pep19-2.5 with stable isotope labeling and acidic hydrolysis
Sepsis is the number one cause of death in intensive care units. This life-threatening condition is caused by bacterial infections and triggered by endotoxins of Gram-negative bacteria that leads to an overreaction of the immune system. The synthetic anti-lipopolysaccharide peptide Pep19-2.5 is a pr...
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| Main Authors: | , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
27 August 2021
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| In: |
Pharmaceutics
Year: 2021, Volume: 13, Issue: 9, Pages: 1-10 |
| ISSN: | 1999-4923 |
| DOI: | 10.3390/pharmaceutics13091342 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.3390/pharmaceutics13091342 Verlag, lizenzpflichtig, Volltext: https://www.mdpi.com/1999-4923/13/9/1342 
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| Author Notes: | Sabrina Wohlfart, Michael Kilian, Philip Storck, Thomas Gutsmann, Klaus Brandenburg and Walter Mier |
| Summary: | Sepsis is the number one cause of death in intensive care units. This life-threatening condition is caused by bacterial infections and triggered by endotoxins of Gram-negative bacteria that leads to an overreaction of the immune system. The synthetic anti-lipopolysaccharide peptide Pep19-2.5 is a promising candidate for the treatment of sepsis as it binds sepsis-inducing lipopolysaccharides and thus prevents initiation of septic shock. For clinical evaluation precise quantification of the peptide in blood and tissue is required. As the peptide is not extractable from biological samples by commonly used methods there is a need for a new analysis method that does not rely on extraction of the peptide. In order to quantify the peptide by mass spectrometry, the peptide was synthesized containing 13C9,15N1-labeled phenylalanine residues. This modification offers high stability during acidic hydrolysis. Following acidic hydrolysis of the samples, the concentration of 13C9,15N1-labeled phenylalanine determined by LC-MS could be unambiguously correlated to the content of Pep19-2.5. Further experiments validated the accuracy of the data. Moreover, the quantification of Pep19-2.5 in different tissues (as studied in Wistar rats) was shown to provide comparable results to the results obtained with radioactively-labeled (14C) Pep19-2.5- Radioactive labeling is considered as the gold standard for quantification of compounds that refrain from reliable extraction methods. This novel method represents a valuable procedure for the determination of Pep19-2.5 and sticky peptides with unpredictable extraction properties in general. |
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| Item Description: | Gesehen am 11.11.2021 This article belongs to the special issue "Quantification of therapeutic peptides by LC-MS" |
| Physical Description: | Online Resource |
| ISSN: | 1999-4923 |
| DOI: | 10.3390/pharmaceutics13091342 |