Pros and cons of peptide isolectric focusing in shotgun proteomics

Applied Proteomics in 'One Health'

‘One Health’ summarises the idea that human health and animal health are interdependent and bound to the health of ecosystems. The purpose of proteomics methodologies and studies is to determine proteins present in samples of interest and to quantify changes in protein expression during pathological conditions. The objectives of this paper are to review the application of proteomics technologies within the One Health concept and to appraise their role in the elucidation of diseases and situations relevant to One Health. The paper develops in three sections. Proteomics Applications in Zoonotic Infections part discusses proteomics applications in zoonotic infections and explores the use of proteomics for studying pathogenetic pathways, transmission dynamics, diagnostic biomarkers and novel vaccines in prion, viral, bacterial, protozoan and metazoan zoonotic infections. Proteomics Applications in Antibiotic Resistance part discusses proteomics applications in mechanisms of resistance development and discovery of novel treatments for antibiotic resistance. Proteomics Applications in Food Safety part discusses the detection of allergens, exposure of adulteration, identification of pathogens and toxins, study of product traits and characterisation of proteins in food safety. Sensitive analysis of proteins, including low-abundant ones in complex biological samples, will be achieved in the future, thus enabling implementation of targeted proteomics in clinical settings, shedding light on biomarker research and promoting the One Health concept.

Viral glycoproteomes: technologies for characterization and outlook for vaccine design

It has long been known that surface proteins of most enveloped viruses are covered with glycans. It has furthermore been demonstrated that glycosylation is essential for propagation and immune evasion for many viruses. The recent development of high-resolution mass spectrometry techniques has enabled identification not only of the precise structures but also the positions of such post-translational modifications on viruses, revealing substantial differences in extent of glycosylation and glycan maturation for different classes of viruses. In-depth characterization of glycosylation and other post-translational modifications of viral envelope glycoproteins is essential for rational design of vaccines and antivirals. In this Review, we provide an overview of techniques used to address viral glycosylation and summarize information on glycosylation of enveloped viruses representing ongoing public health challenges. Furthermore, we discuss how knowledge on glycosylation can be translated to means to prevent and combat viral infections.

IEF peptide fractionation method combined to shotgun proteomics enhances the exploration of rice milk proteome

We conducted a proteomics study in order to detect the proteomic method which provides the most complete characterization of the proteins of rice milk. In particular, we compared the results obtained from LC-MS/MS after protein precipitation with acetone or TCA, as well as the results obtained from LC-MS/MS after protein prefractionation based on SDS-PAGE (GeLC-MS/MS) or ProteoMiner™ technology (ProteoMiner-LC-MS/MS), and after peptide prefractionation based on IEF (pIEF-LC-MS/MS). A total of 158 protein species have been detect in rice milk. The physical-chemical analysis and classification of the identified proteins were also reported. In particular, we showed that pIEF-LC-MS/MS method led to a significant increase in the proteome coverage, allowing the identification of a total of 96 proteins of milk rice. This study demonstrates the utility of a prefractionation step based on pIEF before the shotgun proteomic analysis and offers an in-depth insight into the rice milk proteome.

Isoelectric Point Separations of Peptides and Proteins

The separation of ampholytic components according to isoelectric point has played an important role in isolating, reducing complexity and improving peptide and protein detection. This brief review outlines the basics of isoelectric focusing, including a summary of the historical achievements and considerations in experimental design. Derivative methodologies of isoelectric focusing are also discussed including common detection methods used. Applications in a variety of fields using isoelectric point based separations are provided as well as an outlook on the field for future studies.