Quantitation of Vn96 Peptide using liquid chromatography and mass spectrometry

Abstract

Vn96 is a small commercial peptide created by the Atlantic Cancer Research Institute to extract extra cellular vesicles from blood and plasma samples. The peptide is proven to be a successful coagulation reagent, however the viscous characteristics that encompass the peptide present many analytical challenges. Using liquid chromatography coupled with mass spectrometry, (LCMS), Vn96 was analyzed using three different mass spectrometers; a triple quadrupole, a linear quadrupole ion trap, and a quadrupole orbitrap. An extensive understanding of each instrument was done to determine the best settings for the characterization of Vn96. It is shown that the calibration curve for Vn96 produces a non-zero intercept. During the analysis of Vn96 it was determined that adsorption was occurring at concentrations below 5ug/mL resulting in inconsistent data received by the LCMS. It was determined that use of low bind sample vials is required to eliminate Vn96 from adhering to sample vial walls. Additionally, 20% acetonitrile (ACN) and 1.8M sodium chloride (NaCl) is observed to significantly increase signal intensity of Vn96. The lowest concentration of Vn96 detectable using ethyl acetate and sodium chloride is 10ng/mL.