Mutant forms of staphylococcal nuclease with altered patterns of guanidine hydrochloride and urea denaturation.


Eleven mutant forms of staphylococcal nuclease with one or more defined amino acid substitutions have been analyzed by solvent denaturation by using intrinsic fluorescence to follow the denaturation reaction. On the basis of patterns observed in the value of m--the rate of change of log Kapp (the apparent equilibrium constant between the native and denatured states) with denaturant concentration--these proteins can be grouped into two classes. For class I mutants, the value of m with guanidine hydrochloride is less than the wild-type value and is either constant or increases slightly with increasing denaturant; the value of m with urea is also less than wild type but shows a marked increase with increasing denaturant concentration, often approaching but never exceeding the wild-type value. For class II mutants, m is constant and is greater than wild type in both denaturants, with the increase being consistently larger in guanidine hydrochloride than in urea. When double or triple mutants are constructed from members of the same mutant class, the change in m is usually the sum of the changes produced by each mutation in isolation. One plausible explanation for these altered patterns of denaturation is that chain-chain or chain-solvent interactions in the denatured state have been modified--interactions which appear to involve hydrophobic groups. Study holds ProTherm entries: 2830, 2831, 2832, 2833, 2834, 2835, 2836, 2837, 2838, 2839, 2840, 2841, 2842, 2843, 2844, 2845, 2846, 2847, 2848, 2849, 2850, 2851, 2852, 2853 Extra Details: m is relative to wild type value of 5.07 protein stability; protein denaturation; denatured state;,structural intermediates

Submission Details


Submitter: Connie Wang

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

Version: 1

Publication Details
Shortle D;Meeker AK,Proteins (1986) Mutant forms of staphylococcal nuclease with altered patterns of guanidine hydrochloride and urea denaturation. PMID:3449854
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