FigureS3 for submitted paper "Blood targeted proteomics"

<p>These are the raw datafiles for FigureS3 in supplementary for the submitted paper "Blood targeted proteomics: centrifugal filter sample preparation vs dilute-and-shoot" by Tore Vehus, Ole Kristian Brandtzaeg, Elsa Lundanes and Steven R. Wilson.</p

Raw data for Figure 2 and Figure S3 for paper "Blood targeted proteomics"

<p>These are the raw datafiles for Figure 2 and  Figure S3 for the submitted paper "Blood targeted proteomics: centrifugal filter sample preparation vs dilute-and-shoot" by Tore Vehus, Ole Kristian Brandtzaeg, Elsa Lundanes and Steven R. Wilson.</p

Preprint: A robust peptidomics mass spectrometry platform for measuring oxytocin in plasma and serum

<p>Current approaches to measuring the cyclic peptide oxytocin in plasma/serum are associated with poor selectivity and/or inadequate sensitivity. We here describe a high performance nano liquid chromatography-mass spectrometry platform for measuring OT in human plasma/serum. The platform is extremely robust, allowing laborious sample clean-up steps to be omitted. OT binds strongly to plasma proteins, but a reduction/alkylation procedure breaks this bond, allowing ample detection of total OT. The method showed excellent quantitation properties, and was used to determine total OT levels to 0.5-1.2 ng/mL (evaluated with human plasma and cord serum). The method is compatible with accessible mass spectrometry instrumentation, finally allowing selective and easily comparable oxytocin measurements.</p

Proteomics tools reveal startlingly high amounts of oxytocin in plasma and serum

The neuropeptide oxytocin (OT) is associated with a plethora of social behaviors, and is a key topic at the intersection of psychology and biology. However, tools for measuring OT are still not fully developed. We describe a robust nano liquid chromatography-mass spectrometry (nanoLC-MS) platform for measuring the total amount of OT in human plasma/serum. OT binds strongly to plasma proteins, but a reduction/alkylation (R/A) procedure breaks this bond, enabling ample detection of total OT. The method (R/A + robust nanoLC-MS) was used to determine total OT plasma/serum levels to startlingly high concentrations (high pg/mL-ng/mL). Similar results were obtained when combining R/A and ELISA. Compared to measuring free OT, measuring total OT can have advantages in e.g. biomarker studies.Stanton Foundation; Molecular Life Science initiative of the University of Oslo (MLSuio); Norwegian Research CouncilThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

A. EIC of identified peptide TSVQPSHLFIQDPTMPPHPAPNPLTQLEEAR corresponding to Axin1 in standard mixture, HCT15 cell protein extract digested off-line and on-line.

<p>B. EIC of identified peptide HETGSHDAER corresponding to APC in protein extracts from HCT15 cell line and HCT15 xenograft, respectively. OTER volume was approximately 1.2 µL.</p

Carry-over of the highest abundant peptide ions in a blank following injection of a 10 protein standard mix.

<p>Upper chromatogram: TIC of the standard protein mixture, lower chromatograms; zoom-in of three of the highest abundant ions in the standard protein mix compared to the same ions in the blank (not able to extract). OTER volume was approximately 1.2 µL.</p

Total ion chromatogram (TIC) of a fully automated digested, separated and detected HCT15 lysate, leading to the identification of ∼1500 proteins (data recorded from gradient start).

<p>OTER volume was approximately 1.2 µL.</p

SEM image of the OTER (20 µm ID) (the immobilized enzymes are too small to be visualized in the image).

<p>The polymeric layer was ∼0.4 µm (dry).</p

Graphical overview of the OTER-PLOT nanoproteomic platform.

<p>Graphical overview of the OTER-PLOT nanoproteomic platform.</p