Enzyme-Water Mutualism: Implicational Speculation
Retired. Former Research Fellow, Department of Medicine, Auckland Medical School, Auckland, New Zealand.
Keywords: hydrogen-bonded water, solvated enzymes, mutualism
Received: July 23, 2018; Revised: November 1, 2018; Accepted: November 27, 2018; Published: January 17, 2019; Available Online: January 17, 2019
Water exists as a high density or low density liquid with different physical properties resulting from either of two forms of hydrogen bonds between the H2O molecules. This is significant intracellularly because solutes may favor one form of water or the other setting up local gradients with differing water activities that may not be able to equilibrate by water flux because of volume constraint but by a transition of one water form into the other. It is very likely that this remarkable property of water was exploited by evolutionary forces resulting in a mutualism between vicinal H2O molecule clusters and macromolecules. One outcome of this is the variety of substrate specific enzymes endowed with molecular structures that also select the most advantageous composition of the two water structures available, thereby enhancing the catalytic reactions. Any low density/high density water composition change, due to selective partitioning of enzyme reaction products, provides the mechanism for protein folding; a prerequisite for enzyme cycling.