College of Medicine, King Faisal University, Al Hofuf, Al-Ahsa, Saudi Arabia.
Department of Microbiology, College of Veterinary Medicine, King Faisal University, Al Hofuf, Al-Ahsa, Saudi Arabia.
Biomed Res Int. 2023 May 23;2023:2322286. doi: 10.1155/2023/2322286. eCollection 2023.
Lactoferrin (LF) is a major natural antimicrobial agent secreted in body fluids as a natural innate immunity protein. The action and structure of LF are closely related to its iron-binding capacity with structural reporting in open and closed conformations. This study looked at how lactoferrin structures change in camel (cLF), bovine (bLF), and human (hLF) lactoferrin closed forms after iron is removed from their binding sites. Initially, the sequence comparison between cLF and the LFs of marine mammals, bats, and domestic animals was the most intriguing conclusion. Camel LF is revealed to be more closely related to marine animals (80.36% identity) and bats (79.3% identity) than to terrestrial mammal species (~75.5% identity). Results indicated that cLF was more dynamic in nature than bLF and hLF by showing higher RMSD values. The cLF is known to be half lactoferrin half transferrin; in this study, we show that there are different MD behavior of both iron-binding sites. While LF contains two lobes (C- and N-lobes), the C-lobe showed high fluctuations as N-lobe was more stable in the absence of ferric ions. The C-lobe and N-lobe of cLF react differently at physiological pH, revealing distinct molecular interactions between these components. In addition, cLF showed higher system flexibility derived from its larger RMSD, RMSF, lower intermolecular hydrogen bonds, and higher solvent accessible surface area (SASA).
乳铁蛋白 (LF) 是一种主要的天然抗菌剂,作为天然先天免疫蛋白分泌在体液中。LF 的作用和结构与其铁结合能力密切相关,结构报告显示 LF 具有开放和闭合构象。本研究探讨了在从结合部位去除铁后,骆驼 (cLF)、牛 (bLF) 和人 (hLF) 乳铁蛋白封闭形式中 LF 结构如何变化。最初,cLF 与海洋哺乳动物、蝙蝠和家畜的 LF 之间的序列比较是最有趣的结论。骆驼 LF 与海洋动物 (80.36%同一性) 和蝙蝠 (79.3%同一性) 的关系比与陆地哺乳动物 (~75.5%同一性) 更为密切。结果表明,cLF 比 bLF 和 hLF 更具动态性,表现出更高的 RMSD 值。众所周知,cLF 是一半乳铁蛋白,一半转铁蛋白;在这项研究中,我们表明两个铁结合位点的 MD 行为不同。虽然 LF 包含两个叶(C 叶和 N 叶),但在没有三价铁离子的情况下,C 叶表现出较高的波动,而 N 叶则更稳定。在生理 pH 下,cLF 的 C 叶和 N 叶反应不同,揭示了这些成分之间的独特分子相互作用。此外,cLF 表现出更高的系统灵活性,源自其更高的 RMSD、RMSF、更低的分子间氢键和更高的溶剂可及表面积 (SASA)。