Biochemical characterization of human D-2-hydroxyglutarate dehydrogenase and two disease related variants reveals the molecular cause of D-2-hydroxyglutaric aciduria
摘要:
D-2-hydroxyglutaric aciduria is a neurometabolic disorder, characterized by the accumulation of D-2-hydroxyglutarate (D-2HG) in human mitochondria. Increased levels of D-2HG are detected in humans exhibiting point mutations in the genes encoding isocitrate dehydrogenase, citrate carrier, the electron transferring flavoprotein (ETF) and its downstream electron acceptor ETF-ubiquinone oxidoreductase or D-2-hydroxyglutarate dehydrogenase (hD2HGDH). However, while the pathogenicity of several amino acid replacements in the former four proteins has been studied extensively, not much is known about the effect of certain point mutations on the biochemical properties of hD2HGDH.Therefore, we recombinantly produced wild type hD2HGDH as well as two recently identified disease-related variants (hD2HGDH-I147S and -V444A) and performed their detailed biochemical characterization. We could show that hD2HGDH is a FAD dependent protein, which is able to catalyze the oxidation of D-2HG and D-lactate to alpha-ketoglutarate and pyruvate, respectively. The two variants were obtained as apo-proteins and were thus catalytically inactive. The addition of FAD failed to restore enzymatic activity of the variants, indicating that the cofactor binding site is compromised by the single amino acid replacements. Further analyses revealed that both variants form aggregates that are apparently unable to bind the FAD cofactor.Since, D-2-hydroxyglutaric aciduria may also result from a loss of function of either the ETF or its downstream electron acceptor ETF-ubiquinone oxidoreductase, ETF may serve as the cognate electron acceptor of reduced hD2HGDH. Here, we show that hD2HGDH directly reduces recombinant human ETF, thus establishing a metabolic link between the oxidation of D-2-hydroxyglutarate and the mitochondrial electron transport chain.
Asymmetric transfer hydrogenation by synthetic catalysts in cancer cells
作者:James P. C. Coverdale、Isolda Romero-Canelón、Carlos Sanchez-Cano、Guy J. Clarkson、Abraha Habtemariam、Martin Wills、Peter J. Sadler
DOI:10.1038/nchem.2918
日期:2018.3.1
cells. The formate precursor N-formylmethionine was explored as an alternative to formate in PC3 prostate cancer cells, which are known to overexpress a deformylase enzyme. Transfer-hydrogenation catalysts that generate reductive stress in cancer cells offer a new approach to cancer therapy.
低剂量活性的催化抗癌金属药物可以最大限度地减少副作用,引入对抗耐药性的新作用机制并扩大抗癌药物活性的范围。在这里,我们使用高度稳定的手性半夹心有机金属 Os( II ) 芳烃磺酰二胺配合物,[Os(arene)(TsDPEN)] (TsDPEN, N -( p-甲苯磺酰基)-1,2-二苯基乙二胺),以实现丙酮酸的高度对映选择性还原,丙酮酸是代谢途径中的关键中间体。在水性模型系统和人类癌细胞中都显示出还原,其中无毒浓度的甲酸钠用作氢化物源。催化机制产生对卵巢癌细胞与非癌性成纤维细胞(卵巢和肺)的选择性,后者通常用作健康增殖细胞的模型。甲酸前体N-甲酰甲硫氨酸被探索为 PC3 前列腺癌细胞中甲酸的替代物,已知其过表达去甲酰基酶。在癌细胞中产生还原性应力的转移氢化催化剂为癌症治疗提供了一种新方法。
A chiral spirobifluorene-based bis(salen) zinc(<scp>ii</scp>) receptor towards highly enantioselective binding of chiral carboxylates
作者:Sk Asif Ikbal、Yoko Sakata、Shigehisa Akine
DOI:10.1039/d1dt00218j
日期:——
We have designed a newchiral receptor based on two salen zinc(II) complex units connected with a spirobifluorene framework. The chiral receptor is proven to enantioselectively bind chiral carboxylate guests and the differences between the binding constants of enantiomeric guests were up to more than one order of magnitude.
The Crystal Structure of a Homodimeric<i>Pseudomonas</i>Glyoxalase I Enzyme Reveals Asymmetric Metallation Commensurate with Half-of-Sites Activity
作者:Rohan Bythell-Douglas、Uthaiwan Suttisansanee、Gavin R. Flematti、Michael Challenor、Mihwa Lee、Santosh Panjikar、John F. Honek、Charles S. Bond
DOI:10.1002/chem.201405402
日期:2015.1.7
class of glyoxalase I (Glo1) metalloenzymes are typically homodimeric with two metal‐dependent active sites. While the two active sites share identical amino acid composition, this class of enzyme is optimally active with only one metal per homodimer. We have determined the X‐ray crystalstructure of GloA2, a Zn inactive Glo1 enzyme from Pseudomonas aeruginosa. The presented structures exhibit an unprecedented
乙二醛酶I(Glo1)金属酶的Zn失活类型通常是同二聚体,具有两个金属依赖性的活性位点。尽管两个活性位点共享相同的氨基酸组成,但这类酶在每个同型二聚体中仅含一种金属时具有最佳活性。我们已经确定了GloA2的X射线晶体结构,这是一种来自铜绿假单胞菌的Zn失活的Glo1酶。所呈现的结构展现出前所未有的金属结合排列,与位点一半的活性一致:一个活性位点包含一个激活的Ni 2+离子,而另一个活性位点包含两个失活的Zn 2+离子。双核Zn 2+促进的酶学实验该位点鉴定出GloA2的新的催化性质。除了其先前确定的乙二醛酶I活性外,该酶还可以作为依赖Zn 2+ / Co 2+的水解酶起作用。提出的发现表明,GloA2可以同时容纳两种不同的金属结合结构,每种催化不同的反应。
Substrate and reaction intermediate mimics as inhibitors of 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase
作者:Scott R. Walker、Hemi Cumming、Emily J. Parker
DOI:10.1039/b909241b
日期:——
3-Deoxy-D-arabino-heptulosonate 7-phosphate (DAH7P) synthase catalyses the aldol-like addition of phosphoenolpyruvate (PEP) to D-erythrose 4-phosphate in the first step of the shikimate pathway to aromatic amino acids. A series of compounds, designed to mimic intermediates in the enzyme-catalysed reaction, have been synthesised and tested as inhibitors for the DAH7P synthase from Escherichia coli. The most potent inhibitor was the vinyl phosphonate, (E)-2-methyl-3-phosphonoacrylic acid, with a Ki of 4.7 µM.
Preorganized Homochiral Pyrrole‐Based Receptors that Display Enantioselective Anion Binding
作者:Johannes Karges、Seth M. Cohen
DOI:10.1002/ejoc.202101346
日期:2022.4.27
Herein, a series of tris(pyrrolamide) receptors for anion recognition is presented. The receptors were able to bind to a variety of anions with good affinity, and homochiralreceptors produced a 1.6-fold greater affinity for (S)-(+)-mandelate over (R)-(−)-mandelate, demonstrating the ability to differentiate between these enantiomeric anions.
在此,提出了一系列用于阴离子识别的三(吡咯酰胺)受体。这些受体能够以良好的亲和力与多种阴离子结合,并且纯手性受体对 ( S )-(+)-扁桃酸的亲和力是 ( R )-(−)-扁桃酸的 1.6 倍,这表明其能够区分这些对映体阴离子。