Deoxy hemerythrin

Time-resolved resonance Raman studies of the detailed course of cytochrome interaction with carbon monoxide gives an idea of relaxation and conformational changes in the vicinity of the actual reaction site/ A brief conference report lists rate constants for forward and reverse rate constants for interaction of deoxy-hemerythrin with dioxygen, nitrogen monoxide, hydrazoic acid, formamide, and fluoride/ ... 

Rodriguez JH, Xia YM, Debruimer PG. 1999. Mdssbauer spectroscopy of the spin coupled Fe - FeNO centers of nitrosyl derivatives of deoxy hemerythrin and density functional theory of the FeNO S = 3/2) motif. JAm Chem Soc 121 7846-7863. 

Pulver, S., Proland, W. A., Pox, B. G., Lipscomb, J. D., and Solomon, E. 1., 1993, Spectroscopic studies of the coupled binuclear non-heme iron active site in the fully reduced hydroxylase component of methane monooxygenase Comparison to deoxy and deoxy-azide hemerythrin, J. Am. Chem. Soc. 115 12409912422. 

Hemerythrin is the best studied example and high-resolution X-ray data are available for the deoxy (176), oxy (176), met (177), and azido-met (177) forms. Extensive spectroscopic studies have also been carried out on these forms and on the semi-met Fe" Fe form 178). The active site structure of hemerythrin is illustrated in Fig. 40. The two iron atoms are bridged by an oxygen donor (OH or 0 ) and by two carbox-ylates, one aspartate and one gluamate. The remaining protein donors are five histidine residues, three coordinated to one iron and two to the other. In the deoxy form one iron atom is five coordinate and this vacant site can be occupied by dioxygen in oxyhemerythrin or by other... 

Herrmann, K. M., Schultz, J. and Hermodson, M. A. (1980). Sequence homology between the tyrosine-sensitive 3-deoxy-D-ara zn( -heptulosonate 7-phosphate synthase from Escherichia coli and hemerythrin from Sipunculida. Journal of Biological Chemistry, 255, 7079-81. 

The geometry at the iron centres of the bridged dinuclear unit in hemerythrin in its dioxygen-free deoxy (left) and oxygenated oxy (right) forms, with changes upon dioxygen coordination shown. 

The stracture of hemerythrin in a variety of derivatives (oxy, azido, met, and deoxy) is now well-characterized. With three bridging ligands, a distinctive cofacial bioctahedral stereochemistry is seen (Figure... 

We propose that the two-electron oxidative addition 02-binding model developed for hemerythrin can be generalized to hemoglobin, as shown in Figure 20. The deoxy form is presumed to have weak axial... 

Hemerythrin, deoxy-dioxygen binding, 689 Hemiporphyrazines metal complexes dyes, 91... 

Fig. 1 Active site deoxy and oxy forms of the biological oxygen carriers hemoglobin (Hb), hemocyanin (He), and hemerythrin (Hr).

Figure 33. Active site structures of (A) oxy hemeiythriu (PDB code IHMO), (B) deoxy he-merythrin (PDB code IHMD), (C) oxy DcrH-hemerythrin (PDB code 2AWY), and (D) deoxy DcrH-hemerythrin (PDB code 2AWC).

Holmes MA, Letrong I, Turley S, Sieker LC, Stenkamp RE. 1991. Structures of deoxy and oxy hemerythrin at 2.0 A resolution. JMol Biol 218 583-593. 

Brunold TC, Solomon EL 1999. Reversible dioxygen binding to hemerythrin, 1 electronic structures of deoxy- and oxyhemerythrin. J Am Chem Soc 121 8277-8287. 

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