9IT8

Crystal structure of the ternary complex of lactoperoxidase with nitric oxide and nitrite ion at 1.95 A resolution

9IT8 の概要

• エントリーDOI: 10.2210/pdb9it8/pdb
• 分子名称: Lactoperoxidase, 1,2-ETHANEDIOL, CALCIUM ION, ... (13 entities in total)
• 機能のキーワード: bovine lactoperoxidase, peroxide family, oxidoreductase
• 由来する生物種: Bos taurus (domestic cattle)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 72813.01

構造登録者

Maurya, A.,Ahmad, N.,Sharma, P.,Sharma, S.,Singh, T.P. (登録日: 2024-07-19, 公開日: 2024-09-11, 最終更新日: 2025-05-14)

主引用文献

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

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: 39748619
DOI: 10.1002/prot.26797

実験手法

X-RAY DIFFRACTION (1.954 Å)