Chao/Kosmotropic Properties of Brine Solutions in the Presence of
Ancient Proteins and Their Assistance in the Bioavailability and
Precipitation of Life-Necessary Organic Molecules
Abstract
Chaotropicity (order-destroying) describes the entropic disordering of
lipid bilayers and other biomacromolecules which is caused by substances
dissolved in water. Solvents in water are defined as kosmotropic
(order-making) if they contribute to the stability and structure of
water-water interactions. These interactions between brine solutions
(water and salt) and ancestral proteins (AncC ribonuclease) induce
varying changes in the protein’s structure. Understanding how these
brine solutions and early protein structures interact provides insight
into the origins of life and zones of habitability across the solar
system. Here, we used a molecular dynamics simulator to assess the
reaction of an ancient protein (ribonuclease sequence) when exposed to
.15M and 1.5M concentrations of MgCl2 and NaCl. The ancient ribonuclease
structure responded uniquely to .15M NaCl and both concentrations of
MgCl2. Both the nature of the cation and concentration of the salt
promote different responses and effects in the secondary structures of
the AncC protein. According to the Hoffmeister Series scale, sodium is
more kosmotropic and magnesium is more chaotropic. These two different
salts with two different chao-kosmo properties create two different
responses within the protein structure in that particular brine. This
observation speaks highly to the significance of chao-kosmo influences
on molecular level outcomes.