Energetics of denaturation and m values of staphylococcal nuclease mutants.


In a continuation of an earlier study [Carra, J., Anderson, E., & Privalov, P. (1994) Biochemistry 33, 10842-10850], we used differential scanning calorimetry to measure the enthalpy and heat capacity changes of denaturation for 11 mutant forms of staphylococcal nuclease, including the triple mutant [V66L+G88V+G79S]. Several mutant proteins with m- characteristics of guanidinium chloride denaturation were found to denature via a three-state mechanism with increasing temperature. Enthalpy changes for the transitions from the native to intermediate and from the intermediate to denatured states were determined. In the case of the triple mutant, the enthalpy of the second endothermic transition is greater than that of the first. Observation of this second transition provides an explanation for the previously reported large changes in the delta H denaturation for the triple mutant versus wild-type nuclease. The sequence specificity of structure in the intermediate state is discussed with relevance to m values of guanidinium chloride denaturation. The enthalpic level of the intermediate state depends upon the amino acid sequence, suggesting that stabilizing mutations can increase the extent or cohesion of structure present in the intermediate. Study holds ProTherm entries: 2864, 2865, 2866, 2867, 2868, 2869, 2870, 2871, 2872, 2873, 2874 Extra Details: additive : EDTA(1 mM), staphylococcal nuclease; heat capacity change; energetics;,intermediate state; sequence specificity

Submission Details

ID: dSei3NuY3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:20 p.m.

Version: 1

Publication Details
Carra JH;Privalov PL,Biochemistry (1995) Energetics of denaturation and m values of staphylococcal nuclease mutants. PMID:7849061
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 Thermonuclease P00644 NUC_STAAU
99.3 Thermonuclease Q5HHM4 NUC_STAAC
99.1 Thermonuclease Q99VJ0 NUC_STAAM
99.1 Thermonuclease Q7A6P2 NUC_STAAN
99.3 Thermonuclease Q6GB41 NUC_STAAS
99.3 Thermonuclease Q8NXI6 NUC_STAAW
99.3 Thermonuclease Q6GIK1 NUC_STAAR