Osteocalcin: A bone protein with multiple endocrine functions.

Bones are now recognised as endocrine organs with diverse functions. Osteocalcin, a protein primarily produced by osteoblasts, has garnered significant attention. Research into osteocalcin has revealed its impact on glucose metabolism and its unexpected endocrine role, particularly in its undercarboxylated form (ucOC).

Investigation of Structure-Stabilizing Elements in Proteins by Ion Mobility Mass Spectrometry and Collision-Induced Unfolding.

A recently developed proteolytic reactor, designed for protein structural investigation, was coupled to ion mobility mass spectrometry to monitor collisional cross section (CCS) evolution of model proteins undergoing trypsin-mediated mono enzymatic digestion. As peptides are released during digestion, the CCS of the remaining protein structure may deviate from the classical 2/3 power of the CCS-mass relationship for spherical structures. The classical relationship between CCS and mass (CCS = × ) for spherical structures, assuming a globular shape in the gas phase, may deviate as stabilizing elements are lost during digestion.

Development and validation of an LC-MS/MS method for the simultaneous quantitation of angiotensin (1-7), (1-8), (1-9) and (1-10) in human plasma.

Cardiovascular diseases have cast a significant negative impact on the lives of millions worldwide. Over the years, extensive efforts have been dedicated to enhancing diagnostic and prognostic tools for these diseases. A growing body of evidence indicates that the angiotensin convertase enzyme (ACE) and the angiotensin convertase enzyme 2 (ACE2), and angiotensin peptide levels could hold a pivotal role in assisting clinicians with the management of cardiovascular conditions, notably hypertension and heart failure.

Innovative workflow for the identification of cathepsin K cleavage sites in type I collagen.

Since the late 1990s, cathepsin K cleavage sites in type I collagen have been extensively studied due to its ability to release bone resorption biomarkers such as CTX and NTX. However, gel-based methods and N-sequencing used in these studies lack sensitivity, especially for small to medium peptides. In this work, we propose a degradomics mass spectrometry-based workflow that combines protein digestion, Nano-LC-UDMS, and several software tools to identify cathepsin K cleavage sites.

Concise review on the combined use of immunocapture, mass spectrometry and liquid chromatography for clinical applications.

Immunocapture is now a well-established method for sample preparation prior to quantitation of peptides and proteins in complex matrices. This short review will give an overview of some clinical applications of immunocapture methods, as well as protocols with and without enzymatic digestion in a clinical context. The advantages and limitations of both approaches are discussed in detail.

Label-Free Higher Order Structure and Dynamic Investigation Method of Proteins in Solution Using an Enzymatic Reactor Coupled to Electrospray High-Resolution Mass Spectrometry Detection.

For decades, structural analysis of proteins have received considerable attention, from their sequencing to the determination of their 3D structures either in the free state (e.g., no host-guest system, apoproteins) or (non)covalently bound complexes.

Covalent Cross-Linking as an Enabler for Structural Mass Spectrometry.

The number of studies referring to the structural elucidation of intact biomolecular systems using mass spectrometry techniques has gradually increased in the post-2000s literature topics. As part of native mass spectrometry, this domain capitalizes on the kinetic trapping of physiological folds in view of probing solution-like conformational properties of isolated molecules or complexes after their electrospray transfer to the gas phase. Despite its efficiency for a wide array of analytes, this approach is expected to be pushed to its limits when considering highly dynamic systems or when dealing with nonideal operating conditions.

Multi-Enzymatic Limited Digestion: The Next-Generation Sequencing for Proteomics?

Over the past 40 years, proteomics, generically defined as the field dedicated to the identification and analysis of proteins, has tremendously gained in popularity and potency through advancements in genome sequencing, separative techniques, mass spectrometry, and bioinformatics algorithms. As a consequence, its scope of application has gradually enlarged and diversified to meet specialized topical biomedical subjects. Although the tryptic bottom-up approach is widely regarded as the gold standard for rapid screening of complex samples, its application for precise and confident mapping of protein modifications is often hindered due to partial sequence coverage, poor redundancy in indicative peptides, and lack of method flexibility.