The thermal stability of the tryptic fragment of bovine microsomal cytochrome b5 and a variant containing six additional residues.


Abstract

Thermally induced denaturation has been measured for both oxidised and reduced forms of the tryptic fragment of bovine microsomal cytochrome b5 using spectrophotometric methods. In the oxidised state, the tryptic fragment of cytochrome b5 (Ala7-Lys90) denatures in a single cooperative transition with a midpoint temperature (Tm) of approximately 67 degrees C (pH 7.0). The reduced form of the tryptic fragment of cytochrome b5 shows a higher transition temperature of approximately 73 degrees C at pH 7.0 and this is reflected in the values of delta Hm, delta Sm and delta(delta G) of approximately 310kJ.mol-1, 900J.mol-1.K-1 and 5 kJ.mol-1. Increased thermal stability is demonstrated for a variant protein that contains the first 90 amino acid residues of cytochrome b5. These novel increases in stability are observed in both redox states and result from the presence of six additional residues at the amino-terminus. The two forms of cytochrome b5 do not differ significantly in structure with the results suggesting that the reorganisation energy (lambda) of the variant protein, as measured indirectly from redox-linked differences in conformational stability, is small. Consequently the reported subtle differences in reactivity between variants of cytochrome b5 may result from the presence of additional N-terminal residues on the surface of the protein. Study holds ProTherm entries: 10557, 10558 Extra Details: oxidised cytochrome b5; protein folding; denaturation;,heme

Submission Details

ID: FENfSAJU3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:40 p.m.

Version: 1

Publication Details
Newbold RJ;Hewson R;Whitford D,FEBS Lett. (1992) The thermal stability of the tryptic fragment of bovine microsomal cytochrome b5 and a variant containing six additional residues. PMID:1468578
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
2M33 2013-02-06 Solution NMR structure of full-length oxidized microsomal rabbit cytochrome b5
1B5B 1998-06-17 RAT FERROCYTOCHROME B5 B CONFORMATION, NMR, 1 STRUCTURE
1I5U 2001-03-21 SOLUTION STRUCTURE OF CYTOCHROME B5 TRIPLE MUTANT (E48A/E56A/D60A)
1AQA 1997-09-17 SOLUTION STRUCTURE OF REDUCED MICROSOMAL RAT CYTOCHROME B5, NMR, MINIMIZED AVERAGE STRUCTURE
1IET 1997-04-21 APOCYTOCHROME B5, PH 6.2, 298 K, NMR, MINIMIZED AVERAGE STRUCTURE
1DO9 2000-01-05 SOLUTION STRUCTURE OF OXIDIZED MICROSOMAL RABBIT CYTOCHROME B5. FACTORS DETERMINING THE HETEROGENEOUS BINDING OF THE HEME.
1SH4 2004-08-10 Solution structure of oxidized bovine microsomal cytochrome B5 Mutant V45H
2AXX 1998-03-04 THE SOLUTION STRUCTURE OF OXIDIZED RAT MICROSOMAL CYTOCHROME B5, NMR, 21 STRUCTURES
5XE4 2018-02-14 NMR solution structure of the aromatic mutant H43W H67F cytochrome b5
1IEU 1997-04-21 APOCYTOCHROME B5, PH 6.2, 298 K, NMR, 10 STRUCTURES
1MNY 2002-11-13 Dimethyl propionate ester heme-containing cytochrome b5
1BLV 1998-07-29 SOLUTION STRUCTURE OF OXIDIZED RAT MICROSOMAL CYTOCHROME B5 IN THE PRESENCE OF 2 M GUANIDINIUM CHLORIDE: MONITORING THE EARLY STEPS IN PROTEIN UNFOLDING
1AW3 1998-02-04 THE SOLUTION NMR STRUCTURE OF OXIDIZED RAT MICROSOMAL CYTOCHROME B5, MINIMIZED AVERAGE STRUCTURE
1JEX 2001-07-11 SOLUTION STRUCTURE OF A67V MUTANT OF RAT FERRO CYTOCHROME B5
2I96 2007-09-04 Solution structure of the oxidized microsomal human cytochrome b5
1BFX 1998-08-12 THE SOLUTION NMR STRUCTURE OF THE B FORM OF OXIDIZED RAT MICROSOMAL CYTOCHROME B5, MINIMIZED AVERAGE STRUCTURE
1F04 2000-06-21 SOLUTION STRUCTURE OF OXIDIZED BOVINE MICROSOMAL CYTOCHROME B5 MUTANT (E44A, E48A, E56A, D60A) AND ITS INTERACTION WITH CYTOCHROME C
5XEE 2018-02-14 NMR solution structure of the aromatic mutant H43F H67F cytochrome b5
1J0Q 2003-08-12 Solution Structure of Oxidized Bovine Microsomal Cytochrome b5 mutant V61H
1F03 2000-06-21 SOLUTION STRUCTURE OF OXIDIZED BOVINE MICROSOMAL CYTOCHROME B5 MUTANT (E44A, E48A, E56A, D60A) AND ITS INTERACTION WITH CYTOCHROME C
1B5A 1998-06-17 RAT FERROCYTOCHROME B5 A CONFORMATION, NMR, 1 STRUCTURE
1I87 2001-05-16 SOLUTION STRUCTURE OF THE WATER-SOLUBLE FRAGMENT OF RAT HEPATIC APOCYTOCHROME B5
1NX7 2004-06-15 Solution Structure of Oxidized Bovine Microsomal Cytochrome B5
1IB7 2001-04-04 SOLUTION STRUCTURE OF F35Y MUTANT OF RAT FERRO CYTOCHROME B5, A CONFORMATION, ENSEMBLE OF 20 STRUCTURES
1HKO 2003-03-18 NMR structure of bovine cytochrome b5
1I8C 2001-05-16 SOLUTION STRUCTURE OF THE WATER-SOLUBLE FRAGMENT OF RAT HEPATIC APOCYTOCHROME B5
1AXX 1998-03-04 THE SOLUTION STRUCTURE OF OXIDIZED RAT MICROSOMAL CYTOCHROME B5, NMR, 19 STRUCTURES
3X34 2015-07-15 0.76 Crystal structure of the reduced form of the solubilized domain of porcine cytochrome b5 in form 1 crystal
3X32 2015-07-15 0.83 Crystal structure of the oxidized form of the solubilized domain of porcine cytochrome b5 in form 1 crystal
3X33 2015-07-15 0.93 Crystal structure of the oxidized form of the solubilized domain of porcine cytochrome b5 in form 2 crystal
3X35 2015-07-15 0.95 Crystal structure of the reduced form of the solubilized domain of porcine cytochrome b5 in form 2 crystal
1CYO 1994-11-30 1.5 BOVINE CYTOCHROME B(5)
3OZZ 2011-09-14 1.7 Structure of a cytochrome b5 core-swap mutant
1LQX 2002-09-04 1.8 Crystal structure of V45E mutant of cytochrome b5
1M2I 2003-03-18 1.8 Crystal structure of E44A/E56A mutant of cytochrome b5
1M2M 2003-03-18 1.8 Crystal structure of E44A/E48A/E56A/D60A mutant of cytochrome b5
1M20 2002-09-11 1.8 Crystal Structure of F35Y Mutant of Trypsin-solubilized Fragment of Cytochrome b5
1U9U 2005-02-01 1.86 Crystal structure of F58Y mutant of cytochrome b5
1LR6 2002-09-04 1.9 Crystal structure of V45Y mutant of cytochrome b5
1M59 2003-03-18 1.9 Crystal Structure of P40V Mutant of Trypsin-solubilized Fragment of Cytochrome b5
1EHB 2000-08-09 1.9 CRYSTAL STRUCTURE OF RECOMBINANT TRYPSIN-SOLUBILIZED FRAGMENT OF CYTOCHROME B5
1U9M 2005-02-01 2.0 Crystal structure of F58W mutant of cytochrome b5
1ES1 2000-08-09 2.1 CRYSTAL STRUCTURE OF VAL61HIS MUTANT OF TRYPSIN-SOLUBILIZED FRAGMENT OF CYTOCHROME B5
4HIN 2013-10-16 2.4 2.4A Resolution Structure of Bovine Cytochrome b5 (S71L)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
92.9 Cytochrome b5 P00168 CYB5_ALOSE
90.2 Cytochrome b5 P56395 CYB5_MOUSE
91.3 Cytochrome b5 P00173 CYB5_RAT
90.2 Cytochrome b5 P00167 CYB5_HUMAN
91.3 Cytochrome b5 P00169 CYB5_RABIT
91.3 Cytochrome b5 P00170 CYB5_HORSE
96.7 Cytochrome b5 P00172 CYB5_PIG
100.0 Cytochrome b5 P00171 CYB5_BOVIN