The Heme Iron Coordination Complex in His64(E7)Tyr Recombinant Sperm Whale Myoglobin

Biochemistry ◽  
1994 ◽  
Vol 33 (38) ◽  
pp. 11618-11623 ◽  
Author(s):  
Serge Pin ◽  
Bernard Alpert ◽  
Robert Cortes ◽  
Isabella Ascone ◽  
Mark L. Chiu ◽  
...  
Keyword(s):  
Sperm Whale ◽  
Heme Iron ◽  
Coordination Complex ◽  
Iron Coordination ◽  
Sperm Whale Myoglobin

XAS Study of the Heme Iron Coordination in HIS64(E7)TYR Synthetic Sperm Whale Myoglobin

1993 ◽  
Vol 32 (S2) ◽  
pp. 544
Author(s):  
Robert Cortes ◽  
Isabella Ascone ◽  
Serge Pin ◽  
Bernard Alpert ◽  
Mark L. Chiu ◽  
...  
Keyword(s):  
Sperm Whale ◽  
Heme Iron ◽  
Iron Coordination ◽  
Sperm Whale Myoglobin

Modeling heme protein active sites with the his93gly cavity mutant of sperm whale myoglobin: complexes with nitrogen-, oxygen- and sulfur-donor proximal ligands

2004 ◽  
Vol 08 (03) ◽  
pp. 246-254 ◽  
Author(s):  
Roshan Perera ◽  
John H. Dawson
Keyword(s):  
Active Sites ◽  
Sperm Whale ◽  
Heme Iron ◽  
Ambient Temperatures ◽  
Protein Active Sites ◽  
The Difference ◽  
Two Sides ◽  
Sperm Whale Myoglobin ◽  
Protein Environment ◽  
Sulfur Donor

Recent investigations of the His93Gly (H93G) "cavity" mutant of myoglobin as a versatile scaffold for modeling heme states are described. The difference in accessibility of the two sides of the heme in H93G myoglobin makes it possible to generate mixed ligand adducts in the ferric state that are difficult to prepare with heme models in organic solvents. In addition, the protection provided to the heme by the protein environment allows for the preparation of stable oxyferrous and oxo-iron(IV) complexes at near-ambient temperatures with variable ligands trans to the normally reactive dioxygen and oxo substituents. The extensive range of possible complexes that can be generated using the H93G system is illustrated with examples involving imidazole, phenolate, benzoate, thiolate and thiol ligands bound to the proximal side of the heme iron.

scholarly journals Influence of the heme distal pocket on nitrite binding orientation and reactivity in Sperm Whale myoglobin

2021 ◽  
Vol 478 (4) ◽  
pp. 927-942
Author(s):  
Wilford Tse ◽  
Nathan Whitmore ◽  
Myles R. Cheesman ◽  
Nicholas J. Watmough
Keyword(s):  
Thermal Equilibrium ◽  
Magnetic Circular Dichroism ◽  
Sperm Whale ◽  
Heme Iron ◽  
Nitrite Reduction ◽  
Wild Type ◽  
Nitrite Ion ◽  
Alkaline Transition ◽  
Ferric Heme ◽  
Sperm Whale Myoglobin

Nitrite binding to recombinant wild-type Sperm Whale myoglobin (SWMb) was studied using a combination of spectroscopic methods including room-temperature magnetic circular dichroism. These revealed that the reactive species is free nitrous acid and the product of the reaction contains a nitrite ion bound to the ferric heme iron in the nitrito- (O-bound) orientation. This exists in a thermal equilibrium with a low-spin ground state and a high-spin excited state and is spectroscopically distinct from the purely low-spin nitro- (N-bound) species observed in the H64V SWMb variant. Substitution of the proximal heme ligand, histidine-93, with lysine yields a novel form of myoglobin (H93K) with enhanced reactivity towards nitrite. The nitrito-mode of binding to the ferric heme iron is retained in the H93K variant again as a thermal equilibrium of spin-states. This proximal substitution influences the heme distal pocket causing the pKa of the alkaline transition to be lowered relative to wild-type SWMb. This change in the environment of the distal pocket coupled with nitrito-binding is the most likely explanation for the 8-fold increase in the rate of nitrite reduction by H93K relative to WT SWMb.

scholarly journals The role of Val68(E11) in ligand binding to sperm whale myoglobin. Site-directed mutagenesis of a synthetic gene.

1990 ◽  
Vol 265 (20) ◽  
pp. 11788-11795
Author(s):  
K D Egeberg ◽  
B A Springer ◽  
S G Sligar ◽  
T E Carver ◽  
R J Rohlfs ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Sperm Whale ◽  
Site Directed Mutagenesis ◽  
Synthetic Gene ◽  
Directed Mutagenesis ◽  
Sperm Whale Myoglobin

The crystal structure of myoglobin. VI. Seal myoglobin

1960 ◽  
Vol 258 (1293) ◽  
pp. 181-201 ◽  
Keyword(s):  
Tertiary Structure ◽  
Heavy Atom ◽  
Three Dimensional ◽  
Sperm Whale ◽  
Fourier Synthesis ◽  
Heavy Atoms ◽  
Isomorphous Replacement ◽  
Unit Cells ◽  
The Common ◽  
Sperm Whale Myoglobin

Myoglobin from the common seal ( Phoca vitulina ) when crystallized from ammonium sulphate forms monoclinic crystals with space group the unit cell, a = 57·9Å, b = 29·6Å, c = 106·4Å, β = 102°15', contains four molecules. The method of isomorphous replacement has been used in an investigation of the centrosymmetric b -axis projection in which it has been possible to determine signs for nearly all the h0l reflexions having spacings greater than 4Å. Three independent heavy-atom derivatives were employed and the signs so determined have been used to compute a map of the electron density projected on the (010) plane. This projection has been interpreted in terms of the molecule of sperm-whale myoglobin, as deduced by Bodo, Dintzis, Kendrew & Wyckoff (1959) from a three-dimensional Fourier synthesis to 6Å resolution. The results of the interpretation show that the two myoglobin molecules are very similar in form (tertiary structure) in spite of the differences in their amino-acid composition. The relative orientation of the two unit cells with respect to the myoglobin molecule is given and a comparison is made of the positions of the heavy atoms in each molecule.

The heme iron coordination of unfolded ferric and ferrous cytochrome c in neutral and acidic urea solutions. Spectroscopic and electrochemical studies

2004 ◽  
Vol 1703 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Milan Fedurco ◽  
Jan Augustynski ◽  
Chiara Indiani ◽  
Giulietta Smulevich ◽  
Marián Antalík ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Heme Iron ◽  
Electrochemical Studies ◽  
Iron Coordination
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