Elective Affinities

Dear Colleagues,

Affinity, a complex trait or behaviour noticeable “at first sight” or that develops over time due to a particular reason or tendency, plays an important role in social, biological, and chemical environments. In 1809, the great poet, novelist, statesman, and scientist Johann Wolfgang von Goethe was surprised by the similarities between these rather different fields in his third critically acclaimed and influential novel, Die Wahlverwandtschaften. Our world is built on dynamic processes of attraction and repulsion, which have drastic consequences. Curiously, affinity does not always lead to good outcomes, and what we all know is that it is quite difficult to be controlled or influenced.

At the atomic and molecular levels, the types of interactions which shape the quantum world are extremely diverse. Affinity drives chemical reactions and influences how molecules interact. A simple molecule, such as water, has and mediates so many complex behaviors, never ceasing to surprise us. Water is the main constituent of Earth's hygrosphpere and is vital for all forms of life. A particularly relevant example is that the re-entrant phase transitions in simple hydrogen-bonded systems manifest through a closed-loop immiscibility gap or can drive dynamic substructure droplet formation. Even more, they can turn into rather unusual, reversible, liquid-to-solid phase transitions upon heating (J. Chem. Phys. (2004) 121(11), 5031). Somehow related, liquid–liquid phase transitions have also emerged as a fascinating area of research, providing new insights into the formation of biomolecular condensates and membrane-less organelles, which allow for the spatial organization and compartmentalization of cellular components. If we add here the complexity of protein–protein, protein–DNA, and protein–RNA interactions, we can understand the vastness of systems where selective affinities play a significant role. The dysregulation of these interactions can possibly lead to protein misfolding and aggregation, which are associated with a wide range of diseases, such as neurodegenerative disorders and cataracts. Additionally, we also remember that viruses trick the immune system into escaping antiviral defenses and adapting to easily penetrate and infect cells, which allows them to replicate and spread to new hosts. Post-translational modifications, such as glycosylation, are additionally important here, and glycobiology is also a remarkable field of research. In the same area, antibody production after the natural immune response is time-consuming, costly, and limits feasible targets. Understanding the underlying molecular mechanisms of all these improved affinities and finding ways to modulate them are crucial for developing effective therapeutic strategies.

We encourage researchers with diverse backgrounds, including (bio)physics, (bio)chemistry, structural biology, and molecular biotechnology, to contribute valuable insights to this issue.

Dr. Călin Gabriel Floare
Dr. Elena Matei
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. International Journal of Molecular Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. There is an Article Processing Charge (APC) for publication in this open access journal. For details about the APC please see here. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• re-entrant and liquid-liquid phase transitions
• protein-ligand and protein-protein interactions
• protein folding, misfolding and aggregation
• chaperones
• spectroscopy methods
• structure-function relationship
• conformational transitions
• allostery
• molecular recognition
• molecular docking and molecular dynamics simulations