| Structural highlights
7qzr is a 6 chain structure with sequence from Homo sapiens and Staphylococcus aureus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | X-ray diffraction, Resolution 2.18Å |
| Ligands: | , , , , , , , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Disease
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.[1] [2] [3] [4] [5]
Function
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.
Publication Abstract from PubMed
The heme enzyme myeloperoxidase (MPO) is one of the key players in the neutrophil-mediated killing of invading pathogens as part of the innate immune system. MPO generates antimicrobial oxidants which indiscriminately and effectively kill phagocytosed pathogens. Staphylococcus aureus however is able to escape this fate, in part by secreting a small protein called SPIN (Staphylococcal Peroxidase Inhibitor), which specifically targets and inhibits MPO in a structurally complex manner. Here we present the first crystal structures of the complex of SPIN-aureus and a truncated version (SPIN-truncated) with mature dimeric leukocyte MPO. We unravel the contributions of the two domains to the kinetics and thermodynamics of SPIN-aureus binding to MPO by using a broad array of complementary biochemical and biophysical methods. The C-terminal "recognition" domain is shown to mediate specific binding to MPO, while interaction of the N-terminal "inhibitory" domain is guided mainly by hydrophobic effects and thus is less sequence-dependent. We found that inhibition of MPO is achieved by reducing substrate migration, but SPIN-aureus cannot completely block MPO activity. Its' effectiveness is inversely related to substrate size, with no discernible dependence on other factors. Thus, SPIN-aureus is an extremely high-affinity inhibitor and highly efficient for substrates larger than halogens. As aberrant MPO activity is implicated in a number of chronic inflammatory diseases, SPIN-aureus is the first promising protein inhibitor for specific inhibition of human MPO.
The staphylococcal inhibitory protein SPIN binds to human myeloperoxidase with picomolar affinity but only dampens halide oxidation.,Leitgeb U, Furtmuller PG, Hofbauer S, Brito JA, Obinger C, Pfanzagl V J Biol Chem. 2022 Sep 20:102514. doi: 10.1016/j.jbc.2022.102514. PMID:36150500[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ 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
- ↑ Leitgeb U, Furtmuller PG, Hofbauer S, Brito JA, Obinger C, Pfanzagl V. The staphylococcal inhibitory protein SPIN binds to human myeloperoxidase with picomolar affinity but only dampens halide oxidation. J Biol Chem. 2022 Sep 20:102514. doi: 10.1016/j.jbc.2022.102514. PMID:36150500 doi:http://dx.doi.org/10.1016/j.jbc.2022.102514
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