The interactions between proteins represent complex biological function which can be either beneficial or perilous to the organisms. Interestingly, even the viral infections and their subsequent complications involve protein-protein interactions. Thus, the biophysical tools such as structure and interface determination, binding assays, and aggregation studies provide profound molecular insights which are useful in understanding the pathogenesis of certain diseases and developing the therapeutic strategies. Chapter 1 discusses the fundamentals protein folding, protein-protein interactions and their essence in biological systems. The biophysical techniques that have been used to characterize the protein folding and protein-protein interactions are also tackled. Chapters 2 and 3 involve sp...[ Read more ]

The interactions between proteins represent complex biological function which can be either beneficial or perilous to the organisms. Interestingly, even the viral infections and their subsequent complications involve protein-protein interactions. Thus, the biophysical tools such as structure and interface determination, binding assays, and aggregation studies provide profound molecular insights which are useful in understanding the pathogenesis of certain diseases and developing the therapeutic strategies. Chapter 1 discusses the fundamentals protein folding, protein-protein interactions and their essence in biological systems. The biophysical techniques that have been used to characterize the protein folding and protein-protein interactions are also tackled. Chapters 2 and 3 involve specific protein-protein/peptide interactions related to SARS-CoV-2. Chapter 2 shows the interaction between the truncated peptide of ACE2 (tACE2) conjugated on the surface of the gold nanoparticle and the receptor-binding domain (RBD) of the SARS-CoV-2. This also demonstrates the ability of dynamic light scattering (DLS) to follow binding reaction and derived its binding affinity and kinetics. Chapter 3 provides molecular insights on the interaction between the SARS-CoV-2 protein segments, RBD and SK9, and alpha synuclein (αSyn) to provide a possible explanation on the current clinical correlation between COVID-19 and Parkinsonism. Chapter 4 explores the difference in structure, stability, amyloidogenic propensity, and functionality of SK9 variants by replacing the amino acid sequence in the wildtype SK9. In the event of the interaction, proteins could adopt various conformations from one state to another, these stable or metastable states drives the protein interaction. However, the long withstanding protein folding problem has been dedicated to the prediction of three-dimensional structures. Leveraging a biophysical tool to study the unfolding and refolding pathways at the most fundamental level would allow more detailed elucidation of protein folding beyond their native state which is useful in mapping out the pathogenesis and protein-protein interactions. Hence, chapter 5 focuses on the changes in Raman vibrational signatures during the unfolding of helical and sheet model peptides and the helical SNARE protein.