Why is Glycine not a Part of the Osmoticum in the Urea-rich Cells?
Abstract:Kidney cells of animals including human and marine invertebrates contain high amount of the protein denaturant, urea. Methylamine osmolytes are generally believed to offset the harmful effects of urea on proteins in vitro and in vivo. In this study we have investigated the possibility of glycine to counteract the effects of urea on three proteins by measuring thermodynamic stability, ΔGD o and functional activity parameters (Km and kcat). We discovered that glycine does not counteract the effects of urea in terms of both protein stability and functional activity. We also observed that the glycine alone is compatible with enzymes function and increases protein stability in terms of Tm (midpoint of thermal denaturation) to a great extent. Our study indicates that a most probable reason for the absence of a stabilizing osmolyte, glycine in the urea-rich cells is due to the fact that this osmolyte is non-protective to macromolecules against the hostile effects of urea, and hence is not chosen by evolutionary selection pressure.
Document Type: Research Article
Publication date: 2013-01-01
More about this publication?
- Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function.