Outer sphere contributions within the thiol dioxygenase active site: a combined structure-function study

硫醇双加氧酶活性位点内外球的贡献：结构-功能组合研究

基本信息

批准号：
10579496
负责人：
Bradley S Pierce
金额：
$ 41.37万
依托单位：
UNIVERSITY OF ALABAMA IN TUSCALOOSA
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-15 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10579496
关键词：
Active Sites Address Affinity Amines Amino Acids Anions Binding Binding Sites Catalysis Categories Central Nervous System Charge Computing Methodologies Conserved Sequence Coupled Cysteamine Cysteine Cysteine dioxygenase Diagnostic Dioxygen Dioxygenases Electron Transport Embryo Enzymes Exhibits GTP-Binding Protein Regulators Health Human Hydrogen Bonding Intuition Investigation Iron Kinetics Knowledge Ligands Maintenance Malignant Neoplasms Mammals Measurement Metabolic Diseases Modeling Molecular Mononuclear N-terminal Neurodegenerative Disorders Neurotransmitters Osmoregulation Oxygen Oxygenases Pathway interactions Physiological Play Positioning Attribute Proteins Reaction Reporting Rheumatoid Arthritis Role Sampling Scheme Series Site Skeletal Muscle Specificity Structural Models Structure Substrate Specificity Sulfhydryl Compounds Sulfinic Acids Taurine bile salts carboxylate carboxylation cross reactivity cysteine sulfinic acid cysteinyltyrosine enzyme mechanism enzyme substrate complex experimental study falls heart rhythm human disease hypotaurine iron nitrosyl member nervous system development novel oxidation polypeptide posttranscriptional protein degradation sensor seryl-histidine small molecule spectroscopic survey tool

项目摘要

TITLE. Outer sphere contributions within the thiol dioxygenase active site: a combined structure-function study PROJECT SUMMARY. Thiol dioxygenases (TDOs) are a subset of non-heme mononuclear iron oxygenases that catalyze the O2-dependent oxidation of thiol-bearing substrates to yield the corresponding sulfinic acid. Cysteine dioxygenase (CDO) and cysteamine dioxygenase (ADO) are the only known mammalian TDOs. These enzymes catalyze the oxidation of L-cysteine (CYS) and cysteamine (2-aminoethanthiol, CA) to produce cysteine sulfinic acid (CSA) and hypotaurine (HT), respectively. Ultimately, CSA and HT feed into the mammalian biosynthetic pathways for taurine (TAU). As the most abundant (sulfonic) amino acid derivative in the body, TAU plays a variety of essential functions including osmoregulation, conjugation substrate in the synthesis of bile salts, stabilization of skeletal muscle, maintenance of cardiac rhythm, and an essential neurotransmitter in embryonic central nervous system development. Despite having structurally similar substrates, CDO and ADO exhibit remarkable substrate-specificity; exhibiting no (or negligible) cross-reactivity. Significantly, changes in the cellular expression and/or activity of mammalian TDOs (CDO and ADO) have been correlated with the onset of various human diseases (cancer, neurodegenerative disorders, rheumatoid arthritis, as well as other metabolic disorders). An emerging subset of TDOs are referred to as N-terminal cysteinyl dioxygenases (NCOs). These enzymes are believed to function as physiologic O2-sensors by catalyzing the oxidation of protein N-terminal CYS-residues to initiate protein degradation. A similar function has recently been reported for mammalian ADO in controlling regulators of G protein signaling. Therefore ADO functions both as a small molecule TDO, specific for cysteamine (CA), as well as a NCO by regulating the stability of specific proteins in an O2-dependent fashion. A notable distinction within the NCO active site is the absence of a conserved sequence of spatially adjacent amino acids (Ser-His-Tyr) forming a hydrogen bonding network. This structural motif is highly conserved among structurally characterized TDOs and it is believed to regulate oxygen and thiol-substrate binding affinity at the TDO Fe-site. The absence of this conserved sequence among NCOs suggests a novel mechanism for O2-sensing in this class of enzymes. The central theme of the proposed activities is to investigate the role of outer-sphere interactions within the TDO active site that influence substrate efficiency and recognition. The experiments proposed involve a series of careful kinetic measurements to identify catalytically essential residues within the enzymatic active site. In parallel, spectroscopic and computational methods will be employed to develop a structural model for active site hydrogen-bonding interactions. Similar studies will be performed on members of the NCO class of enzymes to provide a valuable counterpoint to results obtained for TDOs. Potentially these studies will shed light on the mechanisms by which TDOs (and NCOs) regulate specificity of small molecule thiols, polypeptide substrates, and molecular oxygen.

标题。硫醇二氧酶活性位点内的外球贡献：结合结构功能学习项目摘要。硫醇二氧酶（TDOS）是非血红素单核铁氧酶的子集催化硫化底物的O2依赖性氧化以产生相应的硫酸酸。半胱氨酸二氧酶（CDO）和氰氨基二加氧酶（ADO）是唯一已知的哺乳动物TDOS。这些酶催化L-半胱氨酸（Cys）和cysteamine（2-氨基乙醇，CA）的氧化以产生半胱氨酸硫酸（CSA）和次龙（HT）分别。最终，CSA和HT进食哺乳动物牛磺酸（TAU）的生物合成途径。作为体内最丰富（硫酸）氨基酸衍生物， tau扮演着各种基本功能，包括渗透调节，共轭底物合成胆汁盐，骨骼肌的稳定，心律的维持以及必需的神经递质胚胎中枢神经系统发展。尽管结构相似，但CDO和ADO 表现出显着的底物特异性；表现出没有（或可以忽略的）交叉反应性。值得注意的是，变化哺乳动物TDOS（CDO和ADO）的细胞表达和/或活性已与发作相关各种人类疾病（癌症，神经退行性疾病，类风湿关节炎以及其他代谢疾病）。 TDO的新兴子集称为N末端白胱氨酸二加氧酶（NCOS）。这些酶据信通过催化蛋白质N末端的氧化来充当生理O2传感器 Cys-生长蛋白质降解。最近有类似的哺乳动物ADO功能在控制G蛋白信号的调节剂中。因此，ADO既可以用作小分子TDO 对于Cysteamine（CA）以及NCO，通过以O2依赖性方式调节特定蛋白质的稳定性。 NCO活动位点中的一个显着区别是没有一个保守的空间相邻序列形成氢键网络的氨基酸（Ser-His-Tyr）。这种结构图案在结构表征的TDOS，据信可以调节氧气和硫醇 - 基底结合亲和力 TDO FE地点。 NCO中没有这种保守的序列提出了一种新型的O2感应机制在这类酶中。拟议活动的中心主题是调查外部球员的作用 TDO主动部位的相互作用会影响底物效率和识别。实验提出的涉及一系列仔细的动力学测量，以鉴定催化性的基本残基酶促活性位点。同时，将采用光谱和计算方法来开发活性位点氢键相互作用的结构模型。将对成员的成员进行类似的研究 NCO类的酶为TDOS获得的结果提供了有价值的对立点。可能是这些研究将阐明TDOS（和NCO）调节小分子特异性的机制硫醇，多肽底物和分子氧。

项目成果

期刊论文数量（16）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Cooperative redox and spin activity from three redox congeners of sulfur-bridged iron nitrosyl and nickel dithiolene complexes.

DOI：
10.1073/pnas.2201240119
发表时间：
2022-06-21
期刊：
Proceedings of the National Academy of Sciences of the United States of America
影响因子：
11.1
作者：
通讯作者：

Cyanide replaces substrate in obligate-ordered addition of nitric oxide to the non-heme mononuclear iron AvMDO active site.

DOI：
10.1007/s00775-023-01990-7
发表时间：
2023-04
期刊：
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY
影响因子：
3
作者：
York, Nicholas J. J.;Lockart, Molly M. M.;Schmittou, Allison N. N.;Pierce, Brad S. S.
通讯作者：
Pierce, Brad S. S.

Outer-Sphere Tyrosine 159 within the 3-Mercaptopropionic Acid Dioxygenase S-H-Y Motif Gates Substrate-Coordination Denticity at the Non-Heme Iron Active Site.

DOI：
10.1021/acs.biochem.9b00674
发表时间：
2019-12-24
期刊：
BIOCHEMISTRY
影响因子：
2.9
作者：
Sardar, Sinjinee;Weitz, Andrew;Hendrich, Michael P.;Pierce, Brad S.
通讯作者：
Pierce, Brad S.

Nitroxyl Modified Tobacco Mosaic Virus as a Metal-Free High-Relaxivity MRI and EPR Active Superoxide Sensor.

DOI：
10.1021/acs.molpharmaceut.8b00262
发表时间：
2018-08-06
期刊：
Molecular pharmaceutics
影响因子：
4.9
作者：
Dharmarwardana M;Martins AF;Chen Z;Palacios PM;Nowak CM;Welch RP;Li S;Luzuriaga MA;Bleris L;Pierce BS;Sherry AD;Gassensmith JJ
通讯作者：
Gassensmith JJ

Low-Spin Cyanide Complexes of 3-Mercaptopropionic Acid Dioxygenase (MDO) Reveal the Impact of Outer-Sphere SHY-Motif Residues.