Stabilization of myoglobin by multiple alanine substitutions in helical positions.


We have carried out a series of multiple Xaa-->Ala changes at nonadjacent surface positions in the sequence of sperm whale myoglobin. Although the corresponding single substitutions do not increase the thermal stability of the protein, multiple substitutions enhance the stability of the resulting myoglobins. The effect observed is an increase in the observed Tm (midpoint unfolding temperature) relative to that predicted from assuming additivity of the free energy changes corresponding to single mutations. The stabilization occurs in the presence of urea, as measured by the dependence of the unfolding temperature on urea concentration. The sites that have been altered occur in different helices and are not close in sequence or in the native structure of myoglobin. The observed effect is consistent with a role of multiple alanines in residual interactions in the unfolded state of the mutant proteins. Study holds ProTherm entries: 10139, 10140, 10141, 10142, 10143, 10144, 10145, 10146, 10147, 10148, 10149, 10150, 10151, 10152, 10153, 10154, 10155, 10156, 10157, 10158, 10159, 10160, 14518, 14519, 14520, 14521, 14522, 14523, 14524, 14525, 14526, 14527, 14528, 14529, 14530, 14531, 14532, 14533, 14534, 14535, 14536, 14537, 14538, 14539 Extra Details: 0.5 mM of KCN as additive alpha-helix; protein folding; protein stability;,sperm whale myoglobin

Submission Details

ID: 9fa7Dws84

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:39 p.m.

Version: 1

Publication Details
Lin L;Pinker RJ;Phillips GN;Kallenbach NR,Protein Sci. (1994) Stabilization of myoglobin by multiple alanine substitutions in helical positions. PMID:7833805
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 Myoglobin P02185 MYG_PHYMC
96.8 Myoglobin Q0KIY5 MYG_KOGBR
96.8 Myoglobin P02184 MYG_KOGSI
92.9 Myoglobin Q0KIY1 MYG_BALBO
92.9 Myoglobin Q0KIY2 MYG_BALED
92.9 Myoglobin P02177 MYG_ESCRO
92.2 Myoglobin P02178 MYG_MEGNO
91.4 Myoglobin Q0KIY3 MYG_PENEL
91.4 Myoglobin P02181 MYG_INIGE
92.1 Myoglobin P02174 MYG_GLOME
90.9 Myoglobin P02179 MYG_BALAC
91.4 Myoglobin P02173 MYG_ORCOR
90.8 Myoglobin Q0KIY7 MYG1_STEAT
90.8 Myoglobin P68276 MYG_DELDE
90.8 Myoglobin P68279 MYG_TURTR
90.8 Myoglobin P68277 MYG_PHODA
90.8 Myoglobin P68278 MYG_PHOPH
90.3 Myoglobin P02180 MYG_BALPH
90.1 Myoglobin P02183 MYG_MESCA
90.1 Myoglobin Q0KIY0 MYG_MESST
90.1 Myoglobin P02182 MYG_ZIPCA