Contributions of folding cores to the thermostabilities of two ribonucleases H

Srebrenka Robic, James M. Berger, Susan Marqusee

Research output: Contribution to journalArticlepeer-review

Abstract

To investigate the contribution of the folding cores to the thermodynamic stability of RNases H, we used rational design to create two chimeras composed of parts of a thermophilic and a mesophilic RNase H. Each chimera combines the folding core from one parent protein and the remaining parts of the other. Both chimeras form active, well-folded RNases H. Stability curves, based on CD-monitored chemical denaturations, show that the chimera with the thermophilic core is more stable, has a higher midpoint of thermal denaturation, and a lower change in heat capacity (ΔCp) upon unfolding than the chimera with the mesophilic core. A possible explanation for the low ΔCp of both the parent thermophilic RNase H and the chimera with the thermophilic core is the residual structure in the denatured state. On the basis of the studied parameters, the chimera with the thermophilic core resembles a true thermophilic protein. Our results suggest that the folding core plays an essential role in conferring thermodynamic parameters to RNases H.

Original languageEnglish (US)
Pages (from-to)381-389
Number of pages9
JournalProtein Science
Volume11
Issue number2
DOIs
StatePublished - 2002
Externally publishedYes

Keywords

  • Chimera
  • Folding core
  • Heat capacity
  • Ribonuclease H
  • Stability curves
  • Thermodynamic stability of proteins

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

Fingerprint Dive into the research topics of 'Contributions of folding cores to the thermostabilities of two ribonucleases H'. Together they form a unique fingerprint.

Cite this