Transition state of an unfolding step in human cyanomet myoglobin.


We studied an unfolding step of cyanomet myoglobin (Mb) unfolding, for demonstrating dynamical structural changes in the transition state of the process. Three leucine-->alanine mutant Mbs (L29A, L72A and L104A) were prepared for this study. The urea-induced largely monophasic process was monitored by absorption spectroscopy. Linear relations between [urea] and the activation energy (delta G not equal to) of the relaxation for all the Mbs showed that the slope m not equal to urea (= delta(delta G not equal to)/delta[urea])) was altered by either reduction of pH or the L-->A mutations. Thermodynamic interpretations of the changes in m not equal to urea led to a conclusion that the exposed surface area of Mb in the transition state was determined by both protein-core stability and pH conditions. We also performed urea- and acid-denaturation experiments, and gave some inspections on differences between mutational effects on the structure of the transition state and the denatured state. Study holds ProTherm entries: 203, 204, 205, 206 Extra Details: NaCN(0.5 mM) was added in the experiment human cyanomet myoglobin; absorption spectroscopy; transition state;,mutational effects; protein-core stability

Submission Details

ID: uxTm2NKh

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:14 p.m.

Version: 1

Publication Details
Konno T;Morishima I,Biochim. Biophys. Acta (1993) Transition state of an unfolding step in human cyanomet myoglobin. PMID:8448200
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 P02144 MYG_HUMAN
99.4 Myoglobin P02145 MYG_PANTR
99.4 Myoglobin P62734 MYG_HYLAG
99.4 Myoglobin P62735 MYG_SYMSY
99.4 Myoglobin P02147 MYG_GORBE
98.7 Myoglobin P02148 MYG_PONPY
96.1 Myoglobin P68086 MYG_ERYPA
96.1 Myoglobin P68084 MYG_PAPAN
96.1 Myoglobin P68085 MYG_SEMEN
95.5 Myoglobin P02150 MYG_MACFA
94.2 Myoglobin P02163 MYG_ROUAE
93.5 Myoglobin P02189 MYG_PIG
90.3 Myoglobin P14396 MYG_CASFI
90.9 Myoglobin P02152 MYG_CALJA
90.3 Myoglobin P02151 MYG_AOTTR
90.9 Myoglobin P11343 MYG_LUTLU
90.9 Myoglobin P02153 MYG_SAPAP
91.6 Myoglobin P02165 MYG_TUPGL
90.3 Myoglobin P02164 MYG_ORYAF
90.3 Myoglobin P02193 MYG_DIDVI
90.3 Myoglobin P20856 MYG_CTEGU
90.3 Myoglobin P02171 MYG_OCHPR