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|1d7w, resolution 1.90Å ()|
|Ligands:||, , , , , , , , ,|
|Related:||1mhl, 1myp, 1cxp, 1d2v, 1d5l|
CRYSTAL STRUCTURE OF HUMAN MYELOPEROXIDASE ISOFORM C COMPLEXED WITH CYANIDE AND BROMIDE AT PH 4.0
The 1.9 A X-ray crystal structure of human myeloperoxidase complexed with cyanide (R = 0.175, R(free) = 0.215) indicates that cyanide binds to the heme iron with a bent Fe-C-N angle of approximately 157 degrees, and binding is accompanied by movement of the iron atom by 0.2 A into the porphyrin plane. The bent orientation of the cyanide allows the formation of three hydrogen bonds between its nitrogen atom and the distal histidine as well as two water molecules in the distal cavity. The 1.85 A X-ray crystal structure of an inhibitory complex with thiocyanate (R = 0.178, R(free) = 0.210) indicates replacement of chloride at a proximal helix halide binding site in addition to binding in the distal cavity in an orientation parallel with the heme. The thiocyanate replaces two water molecules in the distal cavity and is hydrogen bonded to Gln 91. The 1.9 A structures of the complexes formed by bromide (R = 0.215, R(free) = 0.270) and thiocyanate (R = 0.198, R(free) = 0.224) with the cyanide complex of myeloperoxidase show how the presence of bound cyanide alters the binding site for bromide in the distal heme cavity, while having little effect on thiocyanate binding. These results support a model for a single common binding site for halides and thiocyanate as substrates or as inhibitors near the delta-meso carbon of the porphyrin ring in myeloperoxidase.
Human myeloperoxidase: structure of a cyanide complex and its interaction with bromide and thiocyanate substrates at 1.9 A resolution., Blair-Johnson M, Fiedler T, Fenna R, Biochemistry. 2001 Nov 20;40(46):13990-7. PMID:11705390
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[PERM_HUMAN] Defects in MPO are the cause of myeloperoxidase deficiency (MPOD) [MIM:254600]. A disorder characterized by decreased myeloperoxidase activity in neutrophils and monocytes that results in disseminated candidiasis.
[PERM_HUMAN] Part of the host defense system of polymorphonuclear leukocytes. It is responsible for microbicidal activity against a wide range of organisms. In the stimulated PMN, MPO catalyzes the production of hypohalous acids, primarily hypochlorous acid in physiologic situations, and other toxic intermediates that greatly enhance PMN microbicidal activity.
About this Structure
- Blair-Johnson M, Fiedler T, Fenna R. Human myeloperoxidase: structure of a cyanide complex and its interaction with bromide and thiocyanate substrates at 1.9 A resolution. Biochemistry. 2001 Nov 20;40(46):13990-7. PMID:11705390
- Blasiak LC, Drennan CL. Structural perspective on enzymatic halogenation. Acc Chem Res. 2009 Jan 20;42(1):147-55. PMID:18774824 doi:10.1021/ar800088r
- ↑ Kizaki M, Miller CW, Selsted ME, Koeffler HP. Myeloperoxidase (MPO) gene mutation in hereditary MPO deficiency. Blood. 1994 Apr 1;83(7):1935-40. PMID:8142659
- ↑ Nauseef WM, Brigham S, Cogley M. Hereditary myeloperoxidase deficiency due to a missense mutation of arginine 569 to tryptophan. J Biol Chem. 1994 Jan 14;269(2):1212-6. PMID:7904599
- ↑ Nauseef WM, Cogley M, McCormick S. Effect of the R569W missense mutation on the biosynthesis of myeloperoxidase. J Biol Chem. 1996 Apr 19;271(16):9546-9. PMID:8621627
- ↑ DeLeo FR, Goedken M, McCormick SJ, Nauseef WM. A novel form of hereditary myeloperoxidase deficiency linked to endoplasmic reticulum/proteasome degradation. J Clin Invest. 1998 Jun 15;101(12):2900-9. PMID:9637725 doi:10.1172/JCI2649
- ↑ Romano M, Dri P, Dadalt L, Patriarca P, Baralle FE. Biochemical and molecular characterization of hereditary myeloperoxidase deficiency. Blood. 1997 Nov 15;90(10):4126-34. PMID:9354683