1J80: Osmolyte Stabilization Of Rnase

Osmolytes stabilize proteins to thermal and chemical denaturation. We have studied the effects of the osmolytes sarcosine, betaine, trimethylamine-N-oxide, and taurine on the structure and stability of the protein.peptide complex RNase S using x-ray crystallography and titration calorimetry, respectively. The largest degree of stabilization is achieved with 6 m sarcosine, which increases the denaturation temperatures of RNase S and S pro by 24.6 and 17.4 degrees C, respectively, at pH 5 and protects both proteins against tryptic cleavage. Four crystal structures of RNase S in the presence of different osmolytes do not offer any evidence for osmolyte binding to the folded state of the protein or any perturbation in the water structure surrounding the protein. The degree of stabilization in 6 m sarcosine increases with temperature, ranging from -0.52 kcal mol(-1) at 20 degrees C to -5.4 kcal mol(-1) at 60 degrees C. The data support the thesis that osmolytes that stabilize proteins, do so by perturbing unfolded states, which change conformation to a compact, folding competent state in the presence of osmolyte. The increased stabilization thus results from a decrease in conformational entropy of the unfolded state.
PDB ID: 1J80Download
MMDB ID: 107466
PDB Deposition Date: 2001/5/19
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 2.1  Å
Source Organism:
Bos taurus
Similar Structures:
Biological Unit for 1J80: dimeric; determined by author and by software (PISA)
Molecular Components in 1J80
Label Count Molecule
Proteins (2 molecules)
Ribonuclease Pancreatic(Gene symbol: RNASE1)
Molecule annotation
Ribonuclease Pancreatic(Gene symbol: RNASE1)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

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