Denatured state structural property determines protein stabilization by macromolecular crowding: a thermodynamic and structural approach

PLoS One. 2013 Nov 12;8(11):e78936. doi: 10.1371/journal.pone.0078936. eCollection 2013.

Abstract

Understanding of protein structure and stability gained to date has been acquired through investigations made under dilute conditions where total macromolecular concentration never surpasses 10 g l(-1). However, biological macromolecules are known to evolve and function under crowded intracellular environments that comprises of proteins, nucleic acids, ribosomes and carbohydrates etc. Crowded environment is known to result in altered biological properties including thermodynamic, structural and functional aspect of macromolecules as compared to the macromolecules present in our commonly used experimental dilute buffers (for example, Tris HCl or phosphate buffer). In this study, we have investigated the thermodynamic and structural consequences of synthetic crowding agent (Ficoll 70) on three different proteins (Ribonuclease-A, lysozyme and holo α-lactalbumin) at different pH values. We report here that the effect of crowding is protein dependent in terms of protein thermal stability and structure. We also observed that the structural characteristics of the denatured state determines if crowding will have an effect or not on the protein stability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Hydrogen-Ion Concentration
  • Lactalbumin / genetics
  • Macromolecular Substances / chemistry*
  • Muramidase / chemistry
  • Protein Binding
  • Protein Conformation*
  • Protein Denaturation*
  • Protein Stability
  • Proteins / chemistry*
  • Proteins / metabolism
  • Ribonuclease, Pancreatic / chemistry
  • Thermodynamics

Substances

  • Macromolecular Substances
  • Proteins
  • Lactalbumin
  • Ribonuclease, Pancreatic
  • Muramidase

Grants and funding

This work is supported by grant from Department of Science and Technology (Ref No.: SR/SO/BB-0003/2011). LRS and SM acknowledge Council of Scientific and Industrial Research for the financial assistance provided in the form of research fellowship (File No.: 09/045(1047)/2011-EMR-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.