Fast and Ultrasensitive Glycoform Analysis by Supercritical Fluid Chromatography-Tandem Mass Spectrometry.

The glycoform of a therapeutic monoclonal antibody (mAb) has a significant impact on its effector function as well as its safety and pharmacokinetics. Glycoform heterogeneity is influenced by various factors, including the producing cells and cell culture processes. Therefore, accurate glycoform characterization is essential for drug design, process optimization, manufacturing, and quality control of therapeutic mAbs.

Differential ion mobility mass spectrometry in immunopeptidomics identifies neoantigens carrying colorectal cancer driver mutations.

Understanding the properties of human leukocyte antigen (HLA) peptides (immunopeptides) is essential for precision cancer medicine, while the direct identification of immunopeptides from small biopsies of clinical tissues by mass spectrometry (MS) is still confronted with technical challenges. Here, to overcome these hindrances, high-field asymmetric waveform ion mobility spectrometry (FAIMS) is introduced to conduct differential ion mobility (DIM)-MS by seamless gas-phase fractionation optimal for scarce samples. By established DIM-MS for immunopeptidomics analysis, on average, 42.

Colorectal Cancer-Derived CAT1-Positive Extracellular Vesicles Alter Nitric Oxide Metabolism in Endothelial Cells and Promote Angiogenesis.

Accumulating scientific evidences strongly support the importance of cancer-derived extracellular vesicles (EV) in organization of tumor microenvironment and metastatic niches, which are also considered as ideal tools for cancer liquid biopsy. To uncover the full scope of proteomic information packaged within EVs secreted directly from human colorectal cancer, we cultured surgically resected viable tissues and obtained tissue-exudative EVs (Te-EV). Our quantitative profiling of 6,307 Te-EV proteins and 8,565 tissue proteins from primary colorectal cancer and adjacent normal mucosa ( = 17) allowed identification of a specific cargo in colorectal cancer-derived Te-EVs, high-affinity cationic amino acid transporter 1 (CAT1, = 5.

Citrullination of RGG Motifs in FET Proteins by PAD4 Regulates Protein Aggregation and ALS Susceptibility.

Recent proteome analyses have provided a comprehensive overview of various posttranslational modifications (PTMs); however, PTMs involving protein citrullination remain unclear. We performed a proteomic analysis of citrullinated proteins, and we identified more than 100 PAD4 (peptidyl arginine deiminase 4) substrates. Approximately one-fifth of the PAD4 substrates contained an RG/RGG motif, and PAD4 competitively inhibited the methylation of the RGG motif in FET proteins (FUS, EWS, and TAF15) and hnRNPA1, which are causative genes for ALS (amyotrophic lateral sclerosis).