Development of a Multiplexed LC-MS/MS Assay for the Quantitation of Podocyte Injury Biomarkers Nephrin, Podocalyxin, and Podocin in Human Urine.

CKD is frequently diagnosed only after a significant progression. GFR is the most common indicator of kidney function but is limited in detecting early CKD cases and distinguishing glomerular, tubular, and global CKD. Aiming to provide a glomeruli specific biomarker assay, we developed a peptide immunoaffinity targeted mass spectrometry method for the quantitation of three podocyte specific proteins in human urine: nephrin, podocalyxin, and podocin.

Quantitative Mass Spectrometry Analysis of PD-L1 Protein Expression, -glycosylation and Expression Stoichiometry with PD-1 and PD-L2 in Human Melanoma.

Quantitative assessment of key proteins that control the tumor-immune interface is one of the most formidable analytical challenges in immunotherapeutics. We developed a targeted MS platform to quantify programmed cell death-1 (PD-1), programmed cell death 1 ligand 1 (PD-L1), and programmed cell death 1 ligand 2 (PD-L2) at fmol/microgram protein levels in formalin fixed, paraffin-embedded sections from 22 human melanomas. PD-L1 abundance ranged 50-fold, from ∼0.

WITHDRAWN: Quantitative mass spectrometry analysis of PD-L1 protein expression, N-glycosylation and expression stoichiometry with PD-1 and PD-L2 in human melanoma.

This article has been withdrawn by the authors. We discovered an error after this manuscript was published as a Paper in Press. Specifically, we learned that the structures of glycans presented for the PD-L1 peptide were drawn and labeled incorrectly.