Protein domain-dependent vesiculation of Lipoprotein A, a protein that is important in cell wall synthesis and fitness of the human respiratory pathogen .

The human pathogen causes respiratory tract infections and is commonly associated with prolonged carriage in patients with chronic obstructive pulmonary disease. Production of outer membrane vesicles (OMVs) is a ubiquitous phenomenon observed in Gram-negative bacteria including . OMVs play an important role in various interactions with the human host; from neutralization of antibodies and complement activation to spread of antimicrobial resistance.

Proteomics-Compatible Fourier Transform Isotopic Ratio Mass Spectrometry of Polypeptides.

Measuring the relative abundances of heavy stable isotopes of the elements C, H, N, and O in proteins is of interest in environmental science, archeology, zoology, medicine, and other fields. The isotopic abundance measurements of the fine structure of immonium ions with ultrahigh resolution mass spectrometry obtained in gas-phase fragmentation of polypeptides have previously uncovered anomalous deuterium enrichment in (hydroxy)proline of bone collagen in marine mammals. Here, we provide a detailed description and validation of this approach and demonstrate per mil-range precision of isotopic ratio measurements in aliphatic residues from proteins and cell lysates.

Haptoglobin Induces a Specific Proteomic Profile and a Mature-Associated Phenotype on Primary Human Monocyte-Derived Dendritic Cells.

Damage-associated molecular patterns (DAMPs) play a critical role in dendritic cells (DCs) ability to trigger a specific and efficient adaptive immune response for different physiological and pathological scenarios. We have previously identified constitutive DAMPs (HMGB1 and Calreticulin) as well as new putative inducible DAMPs such as Haptoglobin (HP), from a therapeutically used heat shock-conditioned melanoma cell lysate (called TRIMEL). Remarkably, HP was shown to be the most abundant protein in the proteomic profile of heat shock-conditioned TRIMEL samples.

A mass spectrometry-based non-radioactive differential radial capillary action of ligand assay (DRaCALA) to assess ligand binding to proteins.

Binding of ligands to macromolecules changes their physicochemical and enzymatic characteristics. Cyclic di-GMP is a second messenger involved in motility/sessility and acute/chronic infection life style transition. Although the GGDEF domain, predominantly a diguanylate cyclase, represents one of the most abundant bacterial domain superfamilies, the number of cyclic di-GMP receptors falls short.

Abnormal (Hydroxy)proline Deuterium Content Redefines Hydrogen Chemical Mass.

Analyzing the δH values in individual amino acids of proteins extracted from vertebrates, we unexpectedly found in some samples, notably bone collagen from seals, more than twice as much deuterium in proline and hydroxyproline residues than in seawater. This corresponds to at least 4 times higher δH than in any previously reported biogenic sample. We ruled out diet as a plausible mechanism for such anomalous enrichment.