Structure-Reactivity Relationship in Oxygen and Carbon Monoxide Binding with Some Heme Models

Tétreau, Catherine; Lavalette, Daniel; Momenteau, M.; Fischer, J. R.; Weiss, Raymond

doi:10.1021/ja00105a026

Cited by 56 publications

(101 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the methanol and i PrNO ligands are disordered due to the crystallographic symmetry (inversion center) of the molecule. The C (20) and C (21) atoms of the i PrNO and C(22) of the methanol ligands are further disordered at two sites and refined with occupancy of 0.25 for each carbon atom. The coordinated methanol ligand forms a hydrogen-bond with the methanol solvent molecule, and the distance between O(1) and O(3) is 2.83 (2) A. SHELXTL restraints of EADP, SADI, and ISOR were applied to the disordered atoms to achieve convergence during least-squares refinement.…”

Section: X-ray Crystallographic Studiesmentioning

confidence: 99%

“…Other iron porphyrin compounds containing axial imidazole-based ligands have been characterized by X-ray crystallography, and these include the bis-imidazole complexes (TPP)Fe(1-VinIm) 2 and (TPP)Fe(1-BzlIm) 2 (Fe-N(Im) ¼ 2.004(2), 2.017(4) A) [15], the dioxygen complex (TpivPP)Fe(O 2 )(1-MeIm) (Fe-N(Im) ¼ 2.068 (18) A) [16], the nitro compound (TpivPP)Fe(NO 2 )(HIm) (Fe-N(Im) ¼ 2.037 (10) A) [17], the carbonyl derivatives (por)Fe(CO)(1-MeIm) (Fe-N(Im) ¼ 2.027(5)-2.077 (3) A) [18][19][20][21][22][23][24], and the paramagnetic complex (TPP)Fe(NO)(1-MeIm) containing a bent NO ligand (Fe-N(Im) ¼ 2.173 (2) A) [25]. There are some interesting observations regarding the axial ligand orientations in the (por)Fe( i PrNO)(L) complexes described in this paper.…”

Section: X-ray Crystal Structuresmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and solid-state molecular structures of nitrosoalkane complexes of iron porphyrins containing methanol, pyridine, and 1-methylimidazole ligands

Sohl

Lee

Alguindigue

et al. 2004

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

Section: X-ray Crystallographic Studiesmentioning

confidence: 99%

Section: X-ray Crystal Structuresmentioning

confidence: 99%

Synthesis and solid-state molecular structures of nitrosoalkane complexes of iron porphyrins containing methanol, pyridine, and 1-methylimidazole ligands

Sohl

Lee

Alguindigue

et al. 2004

Journal of Inorganic Biochemistry

View full text Add to dashboard Cite

“…A common approach in the development of have been obtained by combining more than one of low molecular weight hemoprotein models is the the above-mentioned strategies. The works of assembly, around the porphyrin rings, of several Traylor, 49,52 Collman, 48 Momenteau, 51 and Reed [54][55] different chemical moieties, which would resemble are excellent examples of these approaches, and and mimic the protein matrix. Several excellent rethey can be considered fundamental works for the view articles have recently been published with the development of dioxygen binding molecules.…”

Section: Introductionmentioning

confidence: 99%

Miniaturized hemoproteins

et al. 1998

View full text Add to dashboard Cite

The present paper highlights and reviews current research in the field of hemoprotein models. Hemoproteins have been extensively studied in order to understand structure‐function relationships, and to design new molecules with desired functions. A wide number of synthetic analogues have been developed, using quite different approaches. They differ in molecular structures, ranging from simple meso‐substituted tetraaryl‐metalloporphyrins and peptide‐porphyrin conjugates. In this paper we summarize the state of the art on peptide based hemoprotein models. We also report here the approach used by us to develop a new class of molecules, named mimochromes. They can be regarded as miniaturized hemoproteins, because mimochromes are low molecular weight compounds with some structural and functional properties common to those of the parent high molecular weight protein. The basic structure of mimochromes is a deuteroporphyrin ring covalently linked to two helical peptide chains. Two molecules of this series have been fully characterized. All the information derived from their structural analysis has been applied to the design of new analogues with additional functions. © 1998 John Wiley & Sons, Inc. Biopoly 47: 5–22, 1998

show abstract

“…Through the attachment of diverse organic protecting groups to the distal face of model porphyrins, the size, shape, and functionality of such systems can be systematically varied so that steric and electronic factors for CO discrimination can be addressed individually. A large variety of model compounds have been prepared, including "chelated" [18,19], "strapped" [20][21][22][23][24][25][26], "picnic basket" [27], "picket fence" [28,29], "pocket" [30][31][32] and "capped" [33][34][35][36][37][38][39][40] porphyrins as well as hybrids [41][42][43] of these different classifications.…”

mentioning

confidence: 99%

“…Related studies of strapped porphyrin systems are available [43]. The steric barrier in the pocket and capped porphyrins is created by tethering a 1,3,5-substituted or a 1,2,4,5-substituted benzene ring to the ortho positions of 5,10,15,20-tetraphenylporphyrin.…”

mentioning

confidence: 99%

Myoglobin models and steric origins of the discrimination between O2 and CO

Slebodnick

Ibers

1997

J Biol Inorg Chem

View full text Add to dashboard Cite

Synthetic models of the myoglobin active site have provided much insight into factors that affect CO and O 2 binding in the proteins. "Capped" and "pocket" metal porphyrin systems have been developed to probe how steric factors affect ligand binding and ultimately to elucidate important aspects of the mechanism of CO discrimination in the proteins. These model porphyrins are among the most thoroughly characterized systems to date. From the twenty-one known crystal structures, analysis of the types of distortion that occur upon ligand binding under the cap, including porphyrin doming and ruffling, lateral and horizontal movement of the cap, and bending and tilting of the Fe-C-O bond, provides an indication of how steric interactions will affect structure in Hb and Mb. The model porphyrin systems discussed range from those that discriminate against O 2 binding compared to biological systems to those with similar CO and O 2 binding strength to myoglobin, and also to those that bind both O 2 and CO very weakly or not at all. The primary type of distortion observed upon CO binding is vertical or lateral movement of the cap and some ruffling of the porphyrin plane. Minimal bending or tilting of the M-C-O bond is observed, suggesting that the Fe-C-O bending that has been found from crystal structures of the hemoproteins is unlikely.Key words X-ray structure 7 Biomimetic porphyrin 7 Iron 7 Ruthenium 7 Carbonyl Despite the fact that the oxygen-carrying hemoproteins hemoglobin (Hb) and myoglobin (Mb) are among the most studied of the proteins, the question of how structure affects CO and O 2 binding to their heme centers remains contentious. These proteins contain a squareplanar heme [iron(II) protoporphyrin IX] that is embedded in the hydrophobic pocket of the globin; the heme and the globin are connected on the so-called proximal side by a covalent bond between the Fe center and a nitrogen atom of the imidazole group of a histidine residue. An open sixth coordination position on the distal side of the heme is the site of dioxygen binding. Other ligands, including CO, NO, and RNC bind at this site with respective affinities of approximately 10 2 , 10 5 , and 10 -2 times those of O 2 [1]. The binding of CO has been of particular interest because it is discriminated against: although Hb and Mb bind CO more strongly than O 2 , the M value [M p P 1/2 (O 2 )/P 1/2 (CO)] for Hb and Mb is much smaller than it is for unprotected model porphyrin systems [2,3]. This discrimination, which in energy terms amounts to about 4 kcal/ mol, is vital, since CO is produced endogenously in various biological processes [2,4], and approximately 3% of the heme sites in Hb are ligated by CO, even with the discrimination [5].A central question that has led to intense study of biological [6] and model systems [5,7] is how this discrimination occurs. Is O 2 binding stabilized or is CO binding destabilized in the biological systems? In fact, it is likely that both of these processes contribute to the lower value of M by very different chemical means....

show abstract

Structure-Reactivity Relationship in Oxygen and Carbon Monoxide Binding with Some Heme Models

Cited by 56 publications

References 12 publications

Synthesis and solid-state molecular structures of nitrosoalkane complexes of iron porphyrins containing methanol, pyridine, and 1-methylimidazole ligands

Synthesis and solid-state molecular structures of nitrosoalkane complexes of iron porphyrins containing methanol, pyridine, and 1-methylimidazole ligands

Miniaturized hemoproteins

Myoglobin models and steric origins of the discrimination between O2 and CO

Contact Info

Product

Resources

About