Dr. Chris Keating

Professor

Department:  Chemistry
College:  Eberly College of Science
Address:  512 Chemistry Building
Phone:  814-863-7832
E-mail: cmd8@psu.edu
Website: http://research.chem.psu.edu/cdkgroup/

Prebiotic compartmentalization by liquid-liquid phase separation
Compartmentalization is a key step between the formation of organic materials and the appearance of the first protocells. This project studies liquid-liquid phase separation in aqueous solutions as potential source of prebiotic compartments. Phase separation to form dense, organic-rich droplets called “coacervates” could be a mechanism for concentrating rare functional organic molecules on the early Earth and facilitating their activity. Phase separation is common in solutions of widely different molecular composition and under a wide range of solution conditions (pH, salt concentration, organic concentration). Indeed it is difficult not to generate multiple liquid phases when macromolecules are present, particularly as their concentration increases and/or solubility decreases. It therefore seems likely such coexisting liquid phases occurred on the early Earth, and their ability to sequester organic molecules and to assemble particulates such as catalytic clay microparticles or permselectivity-enhancing amphiphile assemblies at their interface could have played several roles in the generation, concentration, and activity of early organic molecules. Although our scientific motivation for this project focuses on understanding prebiotic compartmentalization, the fundamental physical (bio)chemistry of these processes is equally relevant to many consumer products for which compartmentalization by coacervation is common, and for eukaryotic biological cells, which contain membraneless organelles formed via phase separation.

A student joining this research project will initially work closely with a graduate student on identifying conditions of temperature and ionic strength under which phase separation can occur. They will also be invited to join in team meetings with other researchers in our laboratory and collaborators in other laboratories who bring additional expertise in, e.g., RNA catalysis and thermal vent chemistry. If the project is a good fit to the student’s interest, over time they will be expected to become more independent and ideally contribute to peer-reviewed publications.