A thermodynamic study of mutant forms of Streptomyces subtilisin inhibitor. I. Hydrophobic replacements at the position of Met103.


Abstract

The thermodynamic effects of replacing the Met residue at amino acid position 103 of Streptomyces subtilisin inhibitor with other non-polar aliphatic residues were studied by means of differential scanning calorimetry. All but the Leu mutant, which is as stable as the wild-type but has different cooperative units in the course of unfolding, showed destabilization in terms of free energy. Similar losses in free energy, however, were caused by different reasons, i.e. by increased entropy for the Ala mutant and by decreased enthalpy for the Ile mutant, with a tendency that increases in entropy are accompanied by increases in enthalpy. The gain in entropy that caused the largest loss in free energy for the Gly mutant was unexpectedly smaller than that for the Ala mutant. The changes in enthalpy and entropy induced by the mutations exhibited some correlations with hydrophobicity, while no clear correlation was found between the changes in free energy and hydrophobicity. Study holds ProTherm entries: 2364, 2365, 2366, 2367, 2368, 2369, 2370, 2371, 2372, 2373, 2374, 2375, 2376, 2377, 2378, 2379, 2380, 14002, 14003, 14004, 14005, 14006, 14007, 14008, 14009, 14010, 14011, 14012, 14013, 14014, 14015, 14016, 14017, 14018 Extra Details: ddG was computed at Tm of wild type calorimetry; protein stability; hydrophobicity;,folding intermediate; mutagenesis

Submission Details

ID: HMgFyKeV

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:18 p.m.

Version: 1

Publication Details
Tamura A;Sturtevant JM,J. Mol. Biol. (1995) A thermodynamic study of mutant forms of Streptomyces subtilisin inhibitor. I. Hydrophobic replacements at the position of Met103. PMID:7783215
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 PDB Entries

Structure ID Release Date Resolution Structure Title
2SIC 1993-04-15 1.8 REFINED CRYSTAL STRUCTURE OF THE COMPLEX OF SUBTILISIN BPN' AND STREPTOMYCES SUBTILISIN INHIBITOR AT 1.8 ANGSTROMS RESOLUTION
3SIC 1994-01-31 1.8 MOLECULAR RECOGNITION AT THE ACTIVE SITE OF SUBTILISIN BPN': CRYSTALLOGRAPHIC STUDIES USING GENETICALLY ENGINEERED PROTEINACEOUS INHIBITOR SSI (STREPTOMYCES SUBTILISIN INHIBITOR)
5SIC 1994-01-31 2.2 MOLECULAR RECOGNITION AT THE ACTIVE SITE OF SUBTILISIN BPN': CRYSTALLOGRAPHIC STUDIES USING GENETICALLY ENGINEERED PROTEINACEOUS INHIBITOR SSI (STREPTOMYCES SUBTILISIN INHIBITOR)
3SSI 1996-08-17 2.3 PROTEINASE INHIBITOR SSI (STREPTOMYCES SUBTILISIN, INHIBITOR) FROM STREPTOMYCES ALBOGRISEOLUS
2TLD 1992-07-15 2.6 CRYSTAL STRUCTURE OF AN ENGINEERED SUBTILISIN INHIBITOR COMPLEXED WITH BOVINE TRYPSIN

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
90.7 Subtilisin inhibitor P28592 SSI_STRGI
100.0 Subtilisin inhibitor P01006 SSI_STRAO