This work presents a detailed analysis of glycopeptides produced in the tryptic digestion of an IgG1 reference material. Analysis was done by nanospray ESI LC-MS/MS over a wide range of HCD collision energies with both conventional 1D separation for various digestion conditions and a 20 fraction 2D-LC study of a single digest. An extended version of NIST-developed software for analysis of "shotgun" proteomics served to identify the glycopeptides from their precursor masses and product ions for peptides with up to three missed cleavages. A peptide with a single missed cleavage, TKPREEQYNSTYR, was dominant and led to the determination of almost all glycans reported in this study. The 2D studies found a total of 247 glycopeptide ions and 60 glycans of different masses, including 30 glycans found in the 1D studies. This significantly larger number of glycans than found in any other glycoanalysis of therapeutic glycoproteins is due to both the improved separation of sialylated versus asialylated species in the first (high-pH) dimension and the ability to inject large amounts of glycosylated peptides in the 2D studies. Systematic variations in retention with glycan size were also noted. Energy-dependent changes in HCD fragmentation confirmed the proposed glycan structures and led to a peak-annotated mass spectral library to aid the analysis of glycopeptides derived from IgG1 drugs.
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http://dx.doi.org/10.1021/acs.jproteome.5b01046 | DOI Listing |
Data Brief
February 2025
Woodwell Climate Research Center, 149 Woods Hole Rd., Falmouth, MA, 02540, United States.
This near-infrared spectral dataset consists of 2,106 diverse mineral soil samples scanned, on average, on six different units of the same low-cost commercially available handheld spectrophotometer. Most soil samples were selected from the USDA NRCS National Soil Survey Center-Kellogg Soil Survey Laboratory (NSSC-KSSL) soil archives to represent the diversity of mineral soils (0-30 cm) found in the United States, while 90 samples were selected from Ghana, Kenya, and Nigeria to represent available African soils in the same archive. All scanning was performed on dried and sieved (<2 mm) soil samples.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8362, United States.
While gas chromatography mass spectrometry (GC-MS) has long been used to identify compounds in complex mixtures, this process is often subjective and time-consuming and leaves a large fraction of seemingly good-quality spectra unidentified. In this work, we describe a set of new mass spectral library-based methods to assist compound identification in complex mixtures. These methods employ mass spectral uniqueness and compound ubiquity of library entries alongside noise reduction and automated comparison of retention indices to library compounds.
View Article and Find Full Text PDFPLoS One
January 2025
Woodwell Climate Research Center, Falmouth, MA, United States of America.
Soil spectroscopy is a widely used method for estimating soil properties that are important to environmental and agricultural monitoring. However, a bottleneck to its more widespread adoption is the need for establishing large reference datasets for training machine learning (ML) models, which are called soil spectral libraries (SSLs). Similarly, the prediction capacity of new samples is also subject to the number and diversity of soil types and conditions represented in the SSLs.
View Article and Find Full Text PDFSci Total Environ
January 2025
Marine Toxicology, Institute of Marine Research, Bergen, Norway.
Polycyclic aromatic hydrocarbons (PAHs) are toxic contaminants with a widespread presence in diverse environmental contexts. Transformation processes of PAHs via degradation and biotransformation have parallels in humans, animals, plants, fungi, and bacteria. Mapping the transformation products of PAHs is therefore crucial for assessing their toxicological impact and developing effective monitoring strategies.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States.
Consumer products are a major source of chemicals that may pose a health risk. It is important to understand what chemicals are in these products to evaluate risk and assess new products for uncommon ingredients. Suspect screening analysis (SSA) using two-dimensional gas chromatography-high-resolution-time-of-flight/mass spectrometry (GCxGC-HR-TOF/MS) was applied to 92 consumer products from 5 categories.
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