Glycochenodeoxycholate (1-)

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 类固醇和类固醇衍生物
• 英文名称: Glycochenodeoxycholate (1-)
• 英文别名: 2-[[(4R)-4-[(3R,5S,7R,8R,9S,10S,13R,14S,17R)-3,7-dihydroxy-10,13-dimethyl-2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl]pentanoyl]amino]acetate
• 化学式: C26H42NO5-
• 分子量: 448.6
• InChiKey: GHCZAUBVMUEKKP-GYPHWSFCSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  4.9
• 重原子数：
  32
• 可旋转键数：
  5
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.92
• 拓扑面积：
  110
• 氢给体数：
  3
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  PAPS 、 Glycochenodeoxycholate (1-) 生成 Adenosine 3',5'-bismonophosphate(4-) 、 Glycochenodeoxycholate 7-sulfate(2-) 、 氢(+1)阳离子
  参考文献：
  名称：

  The Enzymes, Regulation, and Genetics of Bile Acid Synthesis

  摘要：

  ▪ 摘要：在哺乳动物体内，胆汁酸的合成和排泄构成了胆固醇分解的主要途径。合成提供了一种将既疏水又不溶于水的胆固醇直接转化为水溶性且容易排泄的分子——胆汁酸的直接方法。完成这种转化的生物合成步骤也赋予了胆汁酸的清洁剂特性，这些特性被机体利用来促进从肝脏排泄胆固醇。这种在胆固醇排泄中的作用被胆汁酸溶解膳食胆固醇和必需营养素以及促进它们传递到肝脏的能力所平衡。合成完整的胆汁酸需要17种酶。途径中的选择性酶的表达受到核激素受体和其他转录因子的严格调控，这些因子确保在不断变化的代谢环境中始终有足够的胆汁酸供应。遗传突变会影响胆汁酸的合成，导致一系列人类疾病，从儿童早期的肝衰竭到成年人的渐进性神经病变。

  DOI：

  10.1146/annurev.biochem.72.121801.161712
• 作为产物：
  描述：

  Chenodeoxycholate anion 、 聚甘氨酸 生成 Glycochenodeoxycholate (1-) 、 水
  参考文献：
  名称：

  长双歧杆菌胆汁盐水解酶的生化和遗传学表征。

  摘要：

  从长双歧杆菌SBT2928分离出胆汁盐水解酶（BSH），纯化并鉴定。此外，我们首次描述了双歧杆菌属成员中编码BSH（bsh）的基因的克隆和分析。根据推导的氨基酸序列测定，该酶的天然分子量为125,000-130,000，亚单位分子量为35,024，表明该酶是四聚体。长双歧杆菌BSH的最适pH为5至7，最适温度为40℃。该酶被硫醇酶抑制剂强烈抑制，表明Cys残基可能参与催化反应。长双歧杆菌的BSH可以水解所有六种主要的人胆汁盐和至少两种动物胆汁盐。基于特异性和K（m）值，检测到对甘氨酸缀合的胆汁酸略有偏爱。确定了bsh的核苷酸序列，并将其用于同源性研究，转录本分析以及各种突变体的构建和分析。与其他细菌的BSH和球形芽孢杆菌的青霉素V酰基转移酶（PVA）的同源性很高。基于已经阐明晶体结构的BSH和PVA的相似性，可以将BSH分类为N末端亲核水解酶，而将Cys作为N末端氨基酸。通过定点诱变进行的

  DOI：

  10.1128/aem.66.6.2502-2512.2000

文献信息

• The Human Bile Acid-CoA:Amino Acid N-Acyltransferase Functions in the Conjugation of Fatty Acids to Glycine
  作者：James O'Byrne、Mary C. Hunt、Dilip K. Rai、Masayumi Saeki、Stefan E.H. Alexson

  DOI：10.1074/jbc.m300987200

  日期：2003.9

  Bile acid-CoA:amino acid N-acyltransferase (BACAT) catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile. By use of site-directed mutagenesis and sequence comparisons, we have identified Cys-235, Asp-328, and His-362 as constituting a catalytic triad in human BACAT (hBACAT) and identifying BACAT as a member of the type I acyl-CoA thioesterase gene family. We therefore

  胆汁酸-CoA：氨基酸N-酰基转移酶（BACAT）催化胆汁酸与甘氨酸和牛磺酸的结合，从而排泄到胆汁中。通过使用定点诱变和序列比较，我们已鉴定出Cys-235，Asp-328和His-362构成人BACAT（hBACAT）中的催化三联体，并将BACAT鉴定为I型酰基辅酶A硫酯酶基因家族。因此，我们假设hBACAT也可能将脂肪酰基辅酶A和/或共轭脂肪酸水解为甘氨酸。我们在这里显示重组hBACAT也可以水解长链和非常长链的饱和酰基CoAs（主要是C16：0-C26：0），并且通过质谱法验证了hBACAT还可以将脂肪酸缀合到甘氨酸上。组织表达研究表明，BACAT在肝，胆囊以及近端和远端肠中都有强表达。然而，BACAT还可以在与胆汁酸形成和运输无关的多种组织中表达，这表明在调节长链脂肪酸的细胞内水平方面也起着重要的作用。在人皮肤成纤维细胞中的绿色荧光蛋白定位实验表明，hBACAT酶主要是胞质的。因此
• Hepatic reduction of the secondary bile acid 7-oxolithocholic acid is mediated by 11β-hydroxysteroid dehydrogenase 1
  作者：Alex Odermatt、Thierry Da Cunha、Carlos A. Penno、Charlie Chandsawangbhuwana、Christian Reichert、Armin Wolf、Min Dong、Michael E. Baker

  DOI：10.1042/bj20110022

  日期：2011.6.15

  The oxidized bile acid 7-oxoLCA (7-oxolithocholic acid), formed primarily by gut micro-organisms, is reduced in human liver to CDCA (chenodeoxycholic acid) and, to a lesser extent, UDCA (ursodeoxycholic acid). The enzyme(s) responsible remained unknown. Using human liver microsomes, we observed enhanced 7-oxoLCA reduction in the presence of detergent. The reaction was dependent on NADPH and stimulated by glucose 6-phosphate, suggesting localization of the enzyme in the ER (endoplasmic reticulum) and dependence on NADPH-generating H6PDH (hexose-6-phosphate dehydrogenase). Using recombinant human 11β-HSD1 (11β-hydroxysteroid dehydrogenase 1), we demonstrate efficient conversion of 7-oxoLCA into CDCA and, to a lesser extent, UDCA. Unlike the reversible metabolism of glucocorticoids, 11β-HSD1 mediated solely 7-oxo reduction of 7-oxoLCA and its taurine and glycine conjugates. Furthermore, we investigated the interference of bile acids with 11β-HSD1-dependent interconversion of glucocorticoids. 7-OxoLCA and its conjugates preferentially inhibited cortisone reduction, and CDCA and its conjugates inhibited cortisol oxidation. Three-dimensional modelling provided an explanation for the binding mode and selectivity of the bile acids studied. The results reveal that 11β-HSD1 is responsible for 7-oxoLCA reduction in humans, providing a further link between hepatic glucocorticoid activation and bile acid metabolism. These findings also suggest the need for animal and clinical studies to explore whether inhibition of 11β-HSD1 to reduce cortisol levels would also lead to an accumulation of 7-oxoLCA, thereby potentially affecting bile acid-mediated functions.

  主要由肠道微生物形成的氧化胆汁酸 7-oxoLCA（7-oxolithocholic acid）在人体肝脏中还原成 CDCA（chenodeoxycholic acid），其次是 UDCA（ursodeoxycholic acid）。负责该过程的酶仍然未知。利用人体肝脏微粒体，我们观察到 7-oxoLCA 在去污剂存在的情况下还原能力增强。该反应依赖于 NADPH，并受到 6-磷酸葡萄糖的刺激，这表明该酶定位在 ER（内质网）中，并依赖于 NADPH 生成的 H6PDH（己糖-6-磷酸脱氢酶）。利用重组人 11β-HSD1（11β-羟类固醇脱氢酶 1），我们证明了 7-oxoLCA 向 CDCA 的高效转化，以及 UDCA 的少量转化。与糖皮质激素的可逆代谢不同，11β-HSD1 只介导 7-oxoLCA 及其牛磺酸和甘氨酸共轭物的 7-oxo 还原。此外，我们还研究了胆汁酸对 11β-HSD1 依赖性糖皮质激素相互转化的干扰。7-OxoLCA 及其共轭物优先抑制了可的松的还原，而 CDCA 及其共轭物抑制了可的松的氧化。三维建模解释了所研究胆汁酸的结合模式和选择性。研究结果表明，11β-HSD1 在人体中负责 7-oxoLCA 的还原，这进一步证实了肝脏糖皮质激素激活与胆汁酸代谢之间的联系。这些发现还表明有必要进行动物和临床研究，以探讨抑制 11β-HSD1 以降低皮质醇水平是否也会导致 7-oxoLCA 的积累，从而可能影响胆汁酸介导的功能。
• Crystal Structures of the Binary and Ternary Complexes of 7α-Hydroxysteroid Dehydrogenase from <i>Escherichia coli</i>^,
  作者：Nobutada Tanaka、Takamasa Nonaka、Tetsurou Tanabe、Tadashi Yoshimoto、Daisuke Tsuru、Yukio Mitsui

  DOI：10.1021/bi951904d

  日期：1996.1.1

  structure of the ternary complex [the enzyme complexed with NADH, 7-oxoglycochenodeoxycholic acid (as a reaction product), and possibly partially glycochenodeoxycholic acid (as a substrate)] has been determined by a difference Fourier method at 1.8 A resolution. The enzyme 7 alpha-HSDH is an alpha/beta doubly wound protein having a Rossmann-fold domain for NAD (H) binding. Upon substrate binding, large conformation

  7α-羟基类固醇脱氢酶（7 alpha-HSDH; 1 EC 1.1.1.159）是NAD +依赖性氧化还原酶，属于短链脱氢酶/还原酶（SDR）1家族。它催化胆汁酸类固醇骨架第7位的羟基脱氢。通过多重同构置换方法，已在2.3 A分辨率下解析了7 alpha-HSDH的二元（与NAD +结合）复合物的晶体结构。三元复合物的结构[与NADH，7-氧代糖基去氧胆酸（作为反应产物）和可能的部分糖基去氧胆酸（作为底物）络合的酶]已经通过差示傅里叶方法在1.8A分辨率下确定。酶7 alpha-HSDH是具有针对NAD（H）结合的Rossmann折叠结构域的alpha / beta双链缠绕蛋白。结合底物后，大的构象变化发生在底物结合环（在βF链和αG螺旋之间）和C末端片段（残基250-255）处。底物结合环的可变氨基酸序列似乎是造成SDR家族酶中观察到的多种底物特异性的原因。7α-HSDH三元复合物的晶
• Carboxyl-Terminal and Arg38 are Essential for Activity of the 7&amp;#945;-Hydroxysteroid Dehydrogenase from Clostridium absonum
  作者：Deshuai Lou、Bochu Wang、Jun Tan、Liancai Zhu

  DOI：10.2174/0929866521666140507160050

  日期：2014.7.18

  7α-hydroxysteroid dehydrogenase (7α-HSDH, EC 1.1.1.159), one of the short-chain dehydrogenase/reductase superfamily, catalyzes the dehydrogenation of C7 hydroxyl group of the steroid skeleton of bile acids. Clostridium absonum 7α-HSDH (Ca 7α-HSDH) was cloned and heterologously expressed in Escherichia coli. The function of carboxyterminal (C-terminal) and Arg38 of Ca 7α-HSDH was investigated through

  短链脱氢酶/还原酶超家族之一7α-羟基类固醇脱氢酶（7α-HSDH，EC 1.1.1.159）催化胆汁酸类固醇骨架C7羟基的脱氢。克隆了无性梭菌7α-HSDH（Ca7α-HSDH），并在大肠杆菌中异源表达。通过截短和定点诱变分别研究了Ca7α-HSDH的羧基末端（C末端）和Arg38的功能。当除去C末端的2个和6个氨基酸时，Ca7α-HSDH的催化效率（k（cat）/ K（m））分别保持19.1％和2.5％。此外，缺失8、14和17个氨基酸后无法检测到活性。用天冬氨酸置换第38位的精氨酸后，NADP（+）或NAD（+）的辅酶均未检测到活性。金属离子Mg（2+）（50 mM），Na（+）（200 mM）和K（+）（500 mM）可以分别最大程度地提高Ca7α-HSDH的活性61.4％，64.7％和105.7％。在4或25°C下孵育108小时后，活性没有明显变化，但在37°C下急剧下降。我们的
• Roles of the Ser146, Tyr159, and Lys163 Residues in the Catalytic Action of 7 -Hydroxysteroid Dehydrogenase from Escherichia coli
  作者：T. Tanabe、N. Tanaka、K. Uchikawa、T. Kabashima、K. Ito、T. Nonaka、Y. Mitsui、M. Tsuru、T. Yoshimoto

  DOI：10.1093/oxfordjournals.jbchem.a022159

  日期：1998.9.1

  The Escherichia coli 7α-hydroxysteroid dehydrogenase (7α-HSDH; EC 1.1.1.159) has been the subject of our studies, including the cloning of its gene, and determination of the crystal structures of its binary and ternary complexes [J. Bacteriol 173, 2173–2179 (1991); Biochemistry 35, 7715–7730 (1996)]. Through these studies, the Ser146, Tyr159, and Lys163 residues were found to be involved in its catalytic action. In order to clarify the roles of these residues, we constructed six single mutants of 7α-HSDH, Tyr159-Phe (Y159F), Tyr159-His (Y159H), Lys163-Arg (K163R), Lys163-Ile (K163I), Ser146-Ala (S146A), and Ser146-His (S146H), by site-directed mutagenesis. These mutants were overexpressed in E. coli WSD, which is a 7α-HSDH null strain, and the expressed enzymes were purified to homogeneity. The kinetic constants of the mutant enzymes were determined, and the structures of the Y159F, Y159H, and K163R mutants were analyzed by X-ray crystallography. The Y159F mutant showed no activity, while the Y159H mutant exhibited 13.3% of the wild-type enzyme activity. No remarkable conformational change between the Y159F (or Y159H) and wild-type proteins was detected on X-ray crystallography. On the other hand, the K163I mutant showed just 5.3% of the native enzyme activity, with a 8.5-fold higher Kd. However, the K163R mutant retained 64% activity, and no remarkable conformational change was detected on X-ray crystallography. In the cases of the S146A and S146H mutants, the activities fairly decreased, with 20.3 and 35.6% of kcat of the wild-type, respectively. The data presented in this paper confirm that Tyr159 acts as a basic catalyst, that Lys163 binds to NAD(H) and lowers the pKa value of Tyr159, and that Ser146 stabilizes the substrate, reaction intermediate and product in catalysis.

  大肠杆菌 7α-羟类固醇脱氢酶（7α-HSDH；EC 1.1.1.159）一直是我们研究的对象，包括克隆其基因以及确定其二元和三元复合物的晶体结构 [J. Bacteriol 173, 2173-2179 (1991); Biochemistry 35, 7715-7730 (1996)]。通过这些研究，发现 Ser146、Tyr159 和 Lys163 残基参与了催化作用。为了明确这些残基的作用，我们通过定点突变构建了 6 个 7α-HSDH 的单突变体：Tyr159-Phe (Y159F)、Tyr159-His (Y159H)、Lys163-Arg (K163R)、Lys163-Ile (K163I)、Ser146-Ala (S146A) 和 Ser146-His (S146H)。这些突变体在7α-HSDH无效菌株大肠杆菌WSD中被过表达，表达的酶被纯化至均一。测定了突变体酶的动力学常数，并通过 X 射线晶体学分析了 Y159F、Y159H 和 K163R 突变体的结构。Y159F突变体没有活性，而Y159H突变体的酶活性是野生型的13.3%。在 X 射线晶体学上，没有发现 Y159F（或 Y159H）和野生型蛋白质之间有明显的构象变化。另一方面，K163I 突变体的酶活性仅为野生型的 5.3%，Kd 则高出 8.5 倍。然而，K163R 突变体保留了 64% 的活性，并且在 X 射线晶体学上没有检测到明显的构象变化。S146A 和 S146H 突变体的活性显著降低，分别为野生型 kcat 的 20.3% 和 35.6%。本文提供的数据证实了 Tyr159 起着碱性催化剂的作用，Lys163 与 NAD(H) 结合并降低了 Tyr159 的 pKa 值，而 Ser146 则稳定了催化过程中的底物、反应中间产物和产物。