2-Ketoglutarate taurine

Eichhorn E, JR van der Ploeg, MA Kertesz, T Leisinger (1997) Characterization of an a-ketoglutarate-depen-dent taurine dioxygenase from Escherichia coli. J Biol Chem 272 23031-23036. 

Figure 2.1 X-ray crystal structure of a proposed a-ketoglutarate. The substrate taurine is already intermediate of the TauD catalytic cycle located in its binding pocket near the metal...

Varma, S.D., Devamanoharan, P.S., Ali, A.H., Brozetti, J., Petrali, J., Lehnert, E., Weir, A. (1998b). Half mustard (CEES) induced damage to rabbit cornea attenuating effect of taurine-pymvate-alpha-ketoglutarate-pantothenate mixture. J. Ocul. Pharmacol. Ther. 14 423-8. 

Price JC, Barr EW, Tirupati B, Bollinger JM Jr, Krebs C. The first direct characterization of a high-valent iron intermediate in the reaction of an alpha-ketoglutarate-dependent dioxygenase a high-spin FePV complex in taurine/alpha-ketoglutarate dioxygenase (TauD) from Escherichia coli. Biochemistry 2003 42 7497-7508. 

The resonance Raman spectra of Fe(IV) complexes [(L)FeO]2+, where L = pentadentate pyridylamine ligands, include vFe=0 at 752 cm-1.298 Transient resonance Raman spectra of oxygen intermediates in the non-haem iron enzyme taurine/a-ketoglutarate dioxygenase, include characteristic bands at 812 (160)/787 (lsO) cm-1 and 583 (160)/555 (lsO) cm-1.299 Oxidised intermediates of cytochrome c oxidase give resonance Raman bands for vFe=0 showing that there are three different forms present.300... 

Only since 2003 has there been spectroscopic evidence to support that monomeric, nonheme iron oxygenases cleave O2 and form Fe(IV)=0 species. These findings came from studies on taurine dioxygenase (TauD), a member of the Fe(If)/a-ketoglutarate (a-KG)-dependent hydroxylase superfamily of enzymes [48]. A generic mechanism proposed for hydroxylation is shown in Fig. 6.19 and includes an Fe(IV)=0 intermediate as the competent H-atom abstractor. 

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