Pressure- and temperature-induced unfolding studies: thermodynamics of core hydrophobicity and packing of ribonuclease A.


In this work we demonstrate that heat and pressure induce only slightly different energetic changes in the unfolded state of RNase A. Using pressure and temperature as denaturants on a significant number of variants, and by determining the free energy of unfolding at different temperatures, we estimated the stability of variants unable to complete the unfolding transition owing to the experimental conditions required for pressure experiments. The overall set of results allowed us to map the contributions to stability of the hydrophobic core residues of RNase A, with the positions most critical for stability being V54, V57, I106 and V108. We also show that the stability differences can be attributed to both hydrophobic interactions and packing density with an equivalent energetic magnitude. The main hydrophobic core of RNase A is tightly packed, as shown by the small-to-large and isosteric substitutions. In addition, we found that large changes in the number of methylene groups have non-additive positive stability interaction energies that are consistent with exquisite tight core packing and rearrangements of van der Waals' interactions in the protein interior, even after drastic deleterious substitutions. Study holds ProTherm entries: 21893, 21894, 21896, 21897, 21898, 21899, 21900, 21901, 21902, 21903, 21904, 21905, 21906, 21907, 21908, 21909, 21910, 21911, 21912, 21913, 21914, 21915, 21916, 21917, 21918, 21919, 21920, 21921, 21922, 21923, 21924, 21925, 21926, 21927, 21928, 21929, 21930, 21931, 21932, 21933, 21934, 21935, 21936, 21937, 21938, 21939, 21940, 21941, 21942, 21943, 21944, 21945, 21946, 21947, 21948, 21949, 21950, 21951, 21952, 21953, 21954, 21955, 21956 Extra Details: hydrophobic interactions; packing interactions; pressure denaturation; ribonuclease A; temperature denaturation; UV spectroscopy

Submission Details

ID: aZ4crubV

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:53 p.m.

Version: 1

Publication Details
Font J;Benito A;Torrent J;Lange R;Ribó M;Vilanova M,Biol. Chem. (2006) Pressure- and temperature-induced unfolding studies: thermodynamics of core hydrophobicity and packing of ribonuclease A. PMID:16542150
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Ribonuclease pancreatic P61824 RNAS1_BISBI
100.0 Ribonuclease pancreatic P61823 RNAS1_BOVIN
96.8 Ribonuclease pancreatic P67926 RNAS1_CAPHI
96.8 Ribonuclease pancreatic P67927 RNAS1_SHEEP
95.2 Ribonuclease pancreatic P00657 RNAS1_BUBBU
96.0 Ribonuclease pancreatic P07847 RNAS1_AEPME
93.5 Ribonuclease pancreatic P07848 RNAS1_EUDTH
95.2 Ribonuclease pancreatic P00660 RNAS1_CONTA
92.7 Ribonuclease pancreatic P00668 RNAS1_ANTAM
90.3 Ribonuclease pancreatic P00662 RNAS1_GIRCA
96.0 Ribonuclease pancreatic Q29606 RNAS1_ORYLE