摘要
细胞色素酶P4504(CYP4)家族是人类第二大CYP家族,除CYP4F8、CYP4F12、CYP4X1和CYP4Z1外,大多数CYP4酶都是ω-羟化酶。CYP4Z1是CYP4家族的一个新成员,是目前研究甚少的"孤儿"酶之一,它的过表达会促进乳腺癌中的肿瘤血管生成和生长,并与某些高恶性肿瘤及愈后不良相关,是癌症治疗的潜在药物靶标。月桂酸在各种癌症的治疗和术后康复的调节中发挥重要作用。据报道,月桂酸的链内羟基化由细胞色素CYP4Z1催化,但其催化机制尚不清楚。在这项研究中,使用了量化计算、同源建模、分子对接、分子动力学模拟、自由能分析和主成分分析等方法,深入研究月桂酸羟基化的代谢特征。基于血红素和月桂酸模型的量化计算表明,潜在的羟基化位点的夺氢能垒范围为56.2至85.1 kJ/mol,其中ω-4位点的能垒最低。分子对接的结果表明,活性位点附近的Ser383、Ser113在稳定月桂酸的过程中发挥重要作用。分子动力学模拟结果表明,血红素平面与π-π相互作用形成的共同相互作用,促使ω-4位点更靠近活性氧,这与研究观察结果是一致的。当参与形成π-π相互作用的Phe313突变为Ala313时,对催化选择性的影响消失。自由能分析表明,CYP4Z1活性位点周围的芳香族氨基酸对催化选择性发挥决定性作用。本文探究细胞色素酶P4504Z1主要催化月桂酸的ω-4位点,决定该区域选择性的因素是芳香族氨基酸的π-π相互作用。
The cytochrome enzyme P4504(CYP4)family is the second largest human CYP family.Except CYP4F8,CYP4F12,CYP4X1 and CYP4Z1,most CYP4 enzymes areω-hydroxylases.CYP4Z1 is a new member of the CYP4 family.It is one of the“orphan”enzymes that are rarely studied.Its overexpression promotes tumor angiogenesis and growth in breast cancer and is associated with certain high malignant tumors and poor prognosis,and it is a potential drug target for cancer treatment.Lauric acid plays an important role in the regulation of various cancer treatments and postoperative rehabilitation.Intra-chain hydroxylation of lauric acid is reported to be catalyzed by the cytochrome CYP4Z1,but its catalytic mechanism is unclear.In this study,we used quantitativemethod(QM)calculations,homology modeling,molecular docking,molecular dynamics simulation,free energy analysis,and principal component analysis to gain insights into the metabolic characteristics of lauric acid hydroxylation.QM calculations based on the heme and lauric acid models indicated that the potential hydrogen abstraction energy range of the potential hydroxylation site was 56.2 to 85.1 kJ/mol,suggesting theω-4 site had the lowest barrier.The molecular docking results show that Ser383 and Ser113 around the active site play an important role in stabilizing lauric acid.The molecular dynamics simulation results showed that the common interaction formed by the heme plane and theπ-πinteraction promotes theω-4 site closer to the reactive oxygen,which was consistent with experimental observations.When Phe313 involved in the formation ofπ-πinteraction was mutated to Ala313,the effect on catalytic selectivity disappeared.Free energy analysis showed that aromatic amino acids around the active site of CYP4Z1 play a decisive role in catalytic selectivity.This article explores the cytochrome enzyme P4504Z1 that mainly catalyzes theω-4 site of lauric acid.The factor determining this regioselectivity is theπ-πinteraction of aromatic amino acids.
作者
张超
吕旭东
马宇飞
颜菲
王翠红
张美玲
ZHANG Chao;LV Xu-Dong;MA Yu-Fei;YAN Fei;WANG Cui-Hong;ZHANG Mei-Ling(Biomedical Laboratory,School of Biomedical Engineering and Technology,Tianjin Medical University,Tianjin 300070,China; Department of Physics,School of Science,Tianjin Chengjian University,Tianjin 300384,China)
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2020年第6期689-698,共10页
Chinese Journal of Biochemistry and Molecular Biology
基金
国家自然科学基金(No.10904111,No.11604238)
天津市自然科学基金(No.11JCYBJC14500)
天津市教委科研计划项目(No.2019KJ175)资助。
