Recent advances in top-down proteome sample processing ahead of MS analysis.

Top-down proteomics is emerging as a preferred approach to investigate biological systems, with objectives ranging from the detailed assessment of a single protein therapeutic, to the complete characterization of every possible protein including their modifications, which define the human proteoform. Given the controlling influence of protein modifications on their biological function, understanding how gene products manifest or respond to disease is most precisely achieved by characterization at the intact protein level. Top-down mass spectrometry (MS) analysis of proteins entails unique challenges associated with processing whole proteins while maintaining their integrity throughout the processes of extraction, enrichment, purification, and fractionation. Recent advances in each of these critical front-end preparation processes, including minimalistic workflows, have greatly expanded the capacity of MS for top-down proteome analysis. Acknowledging the many contributions in MS technology and sample processing, the present review aims to highlight the diverse strategies that have forged a pathway for top-down proteomics. We comprehensively discuss the evolution of front-end workflows that today facilitate optimal characterization of proteoform-driven biology, including a brief description of the clinical applications that have motivated these impactful contributions.

Prospects in the use of aptamers for characterizing the structure and stability of bioactive proteins and peptides in food.

Food-derived bioactive proteins and peptides have gained acceptance among researchers, food manufacturers and consumers as health-enhancing functional food components that also serve as natural alternatives for disease prevention and/or management. Bioactivity in food proteins and peptides is determined by their conformations and binding characteristics, which in turn depend on their primary and secondary structures. To maintain their bioactivities, the molecular integrity of bioactive peptides must remain intact, and this warrants the study of peptide form and structure, ideally with robust, highly specific and sensitive techniques. Short single-stranded nucleic acids (i.e. aptamers) are known to have high affinity for cognate targets such as proteins and peptides. Aptamers can be produced cost-effectively and chemically derivatized to increase their stability and shelf life. Their improved binding characteristics and minimal modification of the target molecular signature suggests their suitability for real-time detection of conformational changes in both proteins and peptides. This review discusses the developmental progress of systematic evolution of ligands by exponential enrichment (SELEX), an iterative technology for generating cost-effective aptamers with low dissociation constants (K d) for monitoring the form and structure of bioactive proteins and peptides. The review also presents case studies of this technique in monitoring the structural stability of bioactive peptide formulations to encourage applications in functional foods. The challenges and potential of aptamers in this research field are also discussed. Graphical abstract Advancing bioactive proteins and peptide functionality via aptameric ligands.

Preclinical Evidence on the Anticancer Properties of Food Peptides.

Natural, synthetic and analogues of peptides have shown prospects for application in cancer chemotherapy. Notably, some food protein-derived peptides are known to possess anticancer activities in cultured cancer cells, and also in animal cancer models via different mechanisms including induction of apoptosis, cell cycle arrest, cellular membrane disruption, inhibition of intracellular signalling, topoisomerases and proteases, and antiangiogenic activity. Although the mechanism of several anticancer food peptides is yet to be clearly elucidated, there is potential for practical applications of the peptides as functional food and nutraceutical ingredients, especially in adjuvant cancer therapy. This review describes the aetiological mechanisms of cancers and the production, structures, mechanisms of action, availability, and cellular and physiological anticancer activities of the food peptides.

Nanochemistry of Protein-Based Delivery Agents.

The past decade has seen an increased interest in the conversion of food proteins into functional biomaterials, including their use for loading and delivery of physiologically active compounds such as nutraceuticals and pharmaceuticals. Proteins possess a competitive advantage over other platforms for the development of nanodelivery systems since they are biocompatible, amphipathic, and widely available. Proteins also have unique molecular structures and diverse functional groups that can be selectively modified to alter encapsulation and release properties. A number of physical and chemical methods have been used for preparing protein nanoformulations, each based on different underlying protein chemistry. This review focuses on the chemistry of the reorganization and/or modification of proteins into functional nanostructures for delivery, from the perspective of their preparation, functionality, stability and physiological behavior.

Multiplex Dipstick Technologies for Rapid and Simultaneous Screening of Analytes of Importance in Agri-Food-Nutrition and Health Care: A Review.

Dipstick test kits are being widely used for the rapid screening of a range of antigens or toxins in food, agriculture, and health care. They provide specific results on-site within 10 min with suitable accuracy and are, therefore, cost-effective. Multiplex dipsticks also provide the opportunity for simultaneous detection of multiple antigens in the target sample without using expensive instrumentation, minimizing the cost of analysis as well as the duration of assay. Because of these benefits, dipstick kits are widely being used in the simultaneous detection of several antigens/toxins in large number of samples and in high-throughput manner. This review focuses on the current status of developed multiplex strips and its working principles and future direction of the technology in the agriculture, food, nutrition, and health care sectors.