Transition state of an unfolding step in human cyanomet myoglobin.


Abstract

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 PDB Entries

Structure ID Release Date Resolution Structure Title
3RGK 2011-04-27 1.65 Crystal Structure of Human Myoglobin Mutant K45R
1MWC 1998-08-19 1.7 WILD TYPE MYOGLOBIN WITH CO
1MYG 1994-01-31 1.75 HIGH RESOLUTION X-RAY STRUCTURES OF PIG METMYOGLOBIN AND TWO CD3 MUTANTS MB(LYS45-> ARG) AND MB(LYS45-> SER)
1M6M 1998-08-19 1.8 V68N MET MYOGLOBIN
1MWD 1998-08-19 1.8 WILD TYPE DEOXY MYOGLOBIN
1M6C 1998-08-19 1.9 V68N MYOGLOBIN WITH CO
1MYH 1994-01-31 1.9 HIGH RESOLUTION X-RAY STRUCTURES OF PIG METMYOGLOBIN AND TWO CD3 MUTANTS MB(LYS45-> ARG) AND MB(LYS45-> SER)
1MYJ 1994-01-31 1.9 DISTAL POLARITY IN LIGAND BINDING TO MYOGLOBIN: STRUCTURAL AND FUNCTIONAL CHARACTERIZATION OF A THREONINE68(E11) MUTANT
1MNO 1998-08-19 1.95 V68N MYOGLOBIN OXY FORM
1MDN 1998-09-30 1.98 WILD TYPE MYOGLOBIN WITH CO
1MYI 1994-01-31 2.0 HIGH RESOLUTION X-RAY STRUCTURES OF PIG METMYOGLOBIN AND TWO CD3 MUTANTS MB(LYS45-> ARG) AND MB(LYS45-> SER)
1MNI 1995-04-20 2.07 ALTERATION OF AXIAL COORDINATION BY PROTEIN ENGINEERING IN MYOGLOBIN. BIS-IMIDAZOLE LIGATION IN THE HIS64-->VAL(SLASH)VAL68-->HIS DOUBLE MUTANT
1YCB 1994-01-31 2.1 DISTAL POCKET POLARITY IN LIGAND BINDING TO MYOGLOBIN: DEOXY AND CARBONMONOXY FORMS OF A THREONINE68 (E11) MUTANT INVESTIGATED BY X-RAY CRYSTALLOGRAPHY AND INFRARED SPECTROSCOPY
1MNJ 1995-04-20 2.2 INTERACTIONS AMONG RESIDUES CD3, E7, E10 AND E11 IN MYOGLOBINS: ATTEMPTS TO SIMULATE THE O2 AND CO BINDING PROPERTIES OF APLYSIA MYOGLOBIN
1MNK 1995-04-20 2.2 INTERACTIONS AMONG RESIDUES CD3, E7, E10 AND E11 IN MYOGLOBINS: ATTEMPTS TO SIMULATE THE O2 AND CO BINDING PROPERTIES OF APLYSIA MYOGLOBIN
1MNH 1995-05-08 2.3 INTERACTIONS AMONG RESIDUES CD3, E7, E10 AND E11 IN MYOGLOBINS: ATTEMPTS TO SIMULATE THE O2 AND CO BINDING PROPERTIES OF APLYSIA MYOGLOBIN
1PMB 1990-01-15 2.5 THE DETERMINATION OF THE CRYSTAL STRUCTURE OF RECOMBINANT PIG MYOGLOBIN BY MOLECULAR REPLACEMENT AND ITS REFINEMENT
1YCA 1994-01-31 2.9 DISTAL POCKET POLARITY IN LIGAND BINDING TO MYOGLOBIN: DEOXY AND CARBONMONOXY FORMS OF A THREONINE68 (E11) MUTANT INVESTIGATED BY X-RAY CRYSTALLOGRAPHY AND INFRARED SPECTROSCOPY

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
90.3 Myoglobin P02171 MYG_OCHPR
90.3 Myoglobin P20856 MYG_CTEGU
90.3 Myoglobin P02193 MYG_DIDVI
90.3 Myoglobin P02164 MYG_ORYAF
91.6 Myoglobin P02165 MYG_TUPGL
90.9 Myoglobin P02153 MYG_SAPAP
90.9 Myoglobin P11343 MYG_LUTLU
90.3 Myoglobin P02151 MYG_AOTTR
90.9 Myoglobin P02152 MYG_CALJA
90.3 Myoglobin P14396 MYG_CASFI
93.5 Myoglobin P02189 MYG_PIG
94.2 Myoglobin P02163 MYG_ROUAE
95.5 Myoglobin P02150 MYG_MACFA
96.1 Myoglobin P68085 MYG_SEMEN
96.1 Myoglobin P68084 MYG_PAPAN
96.1 Myoglobin P68086 MYG_ERYPA
98.7 Myoglobin P02148 MYG_PONPY
99.4 Myoglobin P02147 MYG_GORBE
99.4 Myoglobin P62735 MYG_SYMSY
99.4 Myoglobin P62734 MYG_HYLAG
99.4 Myoglobin P02145 MYG_PANTR
100.0 Myoglobin P02144 MYG_HUMAN