Optimized peptide extraction method for analysis of antimicrobial peptide Kn2-7/dKn2-7 stability in human serum by LC-MS.
Future Sci OA 2022;
8:FSO807. [PMID:
35909998 PMCID:
PMC9327644 DOI:
10.2144/fsoa-2022-0013]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 06/16/2022] [Indexed: 11/23/2022] Open
Abstract
Aim:
To develop an extraction protocol and determine stability for antimicrobial peptide (AMP) Kn2-7 and its d-enantiomer dKn2-7 in human serum.
Materials & methods:
We compared use of ethanol, acetonitrile, RapiGest SF Surfactant and 1% formic acid in ethanol for AMP recovery from serum prior to liquid chromatography-mass spectrometry quantification.
Results:
Precipitation of samples with 1% formic acid in ethanol caused the least amount of AMP loss during extraction from serum. Time-course experiments revealed dKn2-7 was significantly more stable than Kn2-7 in 25% serum, with 78.5% of dKn2-7 and only 1.0% of Kn2-7 remaining after 24 h at 37°C.
Conclusion:
The optimized method significantly increased peptide recovery and allowed more accurate and consistent quantification of Kn2-7 and dKn2-7 serum stability.
Antimicrobial peptides are a new class of molecules being studied for treatment of infections. These peptides can easily be broken down by enzymes present in the body. Removal of the peptides by the enzymes might limit the effect of the drugs against an infection. Our work discusses the importance of testing the stability of these peptides in human serum, a bodily fluid that contains a large amount of enzymes. We describe a method to decrease loss of two potential peptide drugs during sample processing. Further, we report results of testing the stability of these two peptide drugs in human serum.
Peptide extraction was optimized for maximum recovery of antimicrobial peptides Kn2-7/dKn2-7 from serum for LC–MS analysis. Time course experiments revealed d-amino acid analogue antimicrobial peptides were more stable against host proteases.
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