Dehaloperoxidase-hemoglobin is the first hemoglobin identified with biologically-relevant oxidative functions, which include peroxidase, peroxygenase and oxidase activities. Herein we report a study of the protein backbone dynamics of DHP using heteronuclear NMR relaxation methods and molecular dynamics (MD) simulations to address the role of protein dynamics in switching from one function to another. The results show that DHP's backbone helical regions and turns have average order parameters of S² = 0.87 ± 0.03 and S² = 0.76 ± 0.08, respectively. Furthermore, DHP is primarily a monomer in solution based on the overall tumbling correlation time τ_m is 9.49 ± 1.65 ns calculated using the prolate diffusion tensor model in the program relax. A number of amino acid residues have significant R_ex using the Lipari-Szabo model-free formalism. These include Lys³, Ile⁶, Leu¹³, Gln¹⁸, Arg³², Ser⁴⁸, Met⁴⁹, Thr⁵⁶, Phe⁶⁰, Arg⁶⁹, Thr⁷¹ Cys⁷³, Ala⁷⁷, Asn⁸¹, Gly⁹⁵, Arg¹⁰⁹, Phe¹¹⁵, Leu¹²⁷ and Met¹³⁶, which may experience slow conformational motions on the microseconds-milliseconds time scale according to the model. Caution should be used when the model contains >4 fitting parameters. The program caver3.0 was used to identify tunnels inside DHP obtained from MD simulation snapshots that are consistent with the importance of the Xe binding site, which is located at the central intersection of the tunnels. These tunnels provide diffusion pathways for small ligands such as O₂, H₂O and H₂O₂ to enter the distal pocket independently of the trajectory of substrates and inhibitors, both of which are aromatic molecules.

脱卤过氧化物酶-血红蛋白是第一个被鉴定为具有生物学相关氧化功能的血红蛋白，其中包括过氧化物酶，过氧化酶和氧化酶活性。本文中，我们报告了使用异核NMR弛豫方法和分子动力学（MD）模拟研究DHP的蛋白质主链动力学的研究，以解决蛋白质动力学在从一种功能切换到另一种功能中的作用。结果表明，DHP的主链螺旋区域和匝数的平均阶数参数分别为S ²  = 0.87±0.03和S ²  = 0.76±0.08。此外，DHP主要是基于总的翻滚相关时间在溶液中的单体τ_米是9.49±1.65纳秒使用扁长扩散张量模型中的程序计算放松一下。使用无Lipari-Szabo模型的形式主义，许多氨基酸残基具有显着的R _ex。这些包括Lys ³，Ile ⁶，Leu ¹³，Gln ¹⁸，Arg ³²，Ser ⁴⁸，Met ⁴⁹，Thr ⁵⁶，Phe ⁶⁰，Arg ⁶⁹，Thr ⁷¹ Cys ⁷³，Ala ⁷⁷，Asn ⁸¹，Gly ⁹⁵，Arg ¹⁰⁹，Phe ¹¹⁵，列伊¹²⁷和大都会¹³⁶，根据模型，它可能会在微秒-毫秒的时间尺度上经历缓慢的构象运动。当模型包含> 4个拟合参数时，应格外小心。Caver3.0程序用于识别从MD模拟快照获得的DHP内部的隧道，这些隧道与Xe绑定站点的重要性一致，Xe绑定站点位于隧道的中央交叉点。这些通道为诸如O ₂，H ₂ O和H ₂ O _2之类的小配体的扩散途径提供了进入远端口袋的途径，而与底物和抑制剂的轨迹无关，而底物和抑制剂都是芳香分子。