9IT8
Crystal structure of the ternary complex of lactoperoxidase with nitric oxide and nitrite ion at 1.95 A resolution
Summary for 9IT8
| Entry DOI | 10.2210/pdb9it8/pdb |
| Descriptor | Lactoperoxidase, 1,2-ETHANEDIOL, CALCIUM ION, ... (13 entities in total) |
| Functional Keywords | bovine lactoperoxidase, peroxide family, oxidoreductase |
| Biological source | Bos taurus (domestic cattle) |
| Total number of polymer chains | 1 |
| Total formula weight | 72813.01 |
| Authors | Maurya, A.,Ahmad, N.,Sharma, P.,Sharma, S.,Singh, T.P. (deposition date: 2024-07-19, release date: 2024-09-11, Last modification date: 2025-05-14) |
| Primary citation | Maurya, A.,Ahmad, N.,Sharma, P.,Sharma, S.,Singh, T.P. Structure of the Complex of Lactoperoxidase With Nitric Oxide at 1.95 angstrom Resolution. Proteins, 93:1079-1089, 2025 Cited by PubMed Abstract: Lactoperoxidase (LPO) is a heme-containing mammalian enzyme that is found in the extracellular fluids of animals including plasma, saliva, airway epithelial and nasal lining fluids, milk, tears, and gastric juices. LPO uses hydrogen peroxide (HO) to convert substrates into oxidized products. Previous structural studies have shown that HO, CO, and CN are bound to LPO at the distal heme cavity by coordinating with heme iron. The structure of the complex of LPO with NO shows that NO also binds to LPO at the distal heme cavity and forms a coordinate linkage with heme iron. The structure shows that the nitrogen atom of NO is linked to heme iron at a distance of 1.97 while the oxygen atom is attached to the N atom of His109 at a distance of 2.23 Å. On the other hand, N atom of NO is located with an interatomic distance of 3.25 Å allowing a hydrogen-bonding interaction with the N atom of Gln105. A comparison of the bindings of NO, CO, CN, and HO in coordination with heme iron indicates stereochemical compatibility of the distal heme cavity for the binding of diatomic molecules. However, notable differences are observed in their orientations in the distal heme cavity indicating functional differences. The bindings of NO, CO, and CN by coordinating with heme iron result in the inhibition of LPO while the binding of HO to heme iron produces an intermediate of LPO known as Compound I. PubMed: 39748619DOI: 10.1002/prot.26797 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.954 Å) |
Structure validation
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