The active site structure of E. coli HPII catalase

FEBS Letters

Zeitler, Caroline M.¹  Kadkhodayan, Saloumeh¹  Dawson, John H.¹  Bracete, Alma M.¹  Chang, Chi K.²  Sono, Masanori¹  Loewen, Peter C.³  Huff, Ann M.¹ 

[1] Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA;Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA;Department of Microbiology, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada

关键词: Magnetic circular dichroism spectroscopy;    Active site structure determination;    Tyrosinate proximal ligand;    EPR spectroscopy;    Catalase;    Dihydroporphyrin;    MCD;    magnetic circular dichroism;    EPR;    electron paramagnetic resonance;    HRP;    horseradish peroxidase;    OEC;    octaethylchlorin;    MeC;    methylchlorin;   

DOI  :  10.1016/0014-5793(91)81401-S

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

E. coli produces 2 catalases known as HPI and HPII. While the heme prosthetic group of the HPII catalase has been established to be a dihydroporphyrin or chlorin, the identity of the proximal ligand to the iron has not been addressed. The magnetic circular dichroism (MCD) spectrum of native ferric HPII catalase is very similar to those of a 5-coordinate phenolate-ligated ferric chlorin complex, a model for tyrosinate proximal ligation, as well as of chlorin-reconstituted ferric horseradish peroxidase, a model for 5-coordinate histidine ligation. However, further MCD comparisons of chlorin-reconstituted myoglobin with parallel ligand-bound adducts of the catalase clearly rule out histidine ligation in the latter, leaving tyrosinate as the best candidate for the proximal ligand.

【 授权许可】

Unknown