Thermal aggregation of a model allosteric protein in different conformational states

Int J Biol Macromol. 2009 Mar 1;44(2):156-62. doi: 10.1016/j.ijbiomac.2008.11.011. Epub 2008 Dec 11.

Abstract

Protein aggregation is of crucial importance in a wide variety of situations. High temperatures, combined with other denaturing conditions, have been used very extensively to decipher some of the fundamentals related to formation of amorphous and fibrillar protein aggregates. The present study reports on the dependency of thermal aggregation of bovine liver glutamate dehydrogenase (GDH), a well-characterized allosteric enzyme, on its conformational state. The initial phases of thermal aggregation of this protein was followed in the presence of a number of well-known allosteric ligands. Positive effectors were found to decrease the rate and extent of aggregation in a concentration dependent manner, while negative effectors did the reverse. ADP, one of the most characterized GDH activators was found to stabilize a specific protein conformation resulting in loss of propensity to aggregate. The importance of this observation related to control of protein-protein interactions leading to protein aggregation is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / pharmacology
  • Allosteric Regulation / drug effects
  • Circular Dichroism
  • Glutamate Dehydrogenase / chemistry*
  • Hot Temperature*
  • Models, Biological*
  • Models, Molecular
  • NAD / pharmacology
  • Particle Size
  • Protein Structure, Quaternary
  • Solutions
  • Spectrometry, Fluorescence

Substances

  • Solutions
  • NAD
  • Adenosine Diphosphate
  • Glutamate Dehydrogenase