Amino acid conjugation of bile acids

胆汁酸的氨基酸缀合

• 批准号: 7101799
• 负责人: STEPHEN BARNES
• 金额: $ 20.32万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7101799
• 关键词: acid thiol ligase; active sites; acyltransferase; chemical conjugate; cholanate compound; coenzyme A; cysteine; enzyme activity; enzyme mechanism; enzyme structure; enzyme substrate; gene targeting; genetic library; glycine; high performance liquid chromatography; laboratory rat; liver metabolism; matrix assisted laser desorption ionization; protein sequence; steroid metabolism; taurine

DESCRIPTION (provided by applicant): In virtually all modern species, including man, the formation of amino acid conjugates (amidates) of bile acids (BA) is quantitatively the most important step in BA metabolism. These conjugates because of their low pKas are effective micellar detergents even in the acid milieu of the upper gut. BA amidation is catalyzed by two enzymes, bile acid CoA ligase and bile acid CoA:amino acid N-acyltransferase (BAT). The long-term goal of this project is to determine the effects of defects in bile acid amidation in human health and disease. This will be approached in several ways using various molecular biology reagents (cloned cDNAs and specific antibodies) that we have prepared in the previous grant periods. We propose to determine how BAT could be sensitive to specific genetic mutations and to post-translational modifications that may occur in liver disease. This involves (1) the identification of critical residues that (a) account for BAT enzyme activity, (b) for the marked differences in glycine/taurine substrate specificity amongst, humans, mice and rats, (c) the effect of mutation of the Cys-235 to Ser on the enzymatic properties of this protein, (d) the effect of the Met- 76 to Val mutation observed in children with cholestasis and other hepatobiliary disease symptoms in an Amish kindred, and (e) the effect of each mutation on BAT structure using H-D exchange/mass spectrometry; (2) the control of peroxisomal localization of BAT using biochemical and molecular biology approaches; and (3) the effect of reactive oxygen species and reactive nitrogen species generated in cholestatic and inflammatory liver disease on BAT activity (modeled in vitro, in hepatocytes and in animal models), in particular, on the cysteine sulfhydryl groups (Cys-235 and Cys372), but potentially other groups such as tyrosine and histidine residues. Overall, these experiments will utilize a combination of molecular biology, enzyme biochemistry, animal models, and mass spectrometry to identify protein modifications of BAT in order to determine the consequence of defects in BA amidation that occur genetically or epigenetically as a consequence of the inflammatory complications of hepatobiliary disease.

描述（申请人提供）：在几乎所有现代物种（包括人类）中，胆汁酸（BA）的氨基酸缀合物（酰胺化物）的形成在数量上是BA代谢中最重要的步骤。这些缀合物由于其低pKa是有效的胶束洗涤剂，即使在上消化道的酸性环境中也是如此。BA酰胺化由两种酶催化，胆汁酸CoA连接酶和胆汁酸CoA：氨基酸N-酰基转移酶（BAT）。该项目的长期目标是确定胆汁酸酰胺化缺陷对人类健康和疾病的影响。这将通过几种方式使用我们在以前的资助期准备的各种分子生物学试剂（克隆的cDNA和特异性抗体）来实现。我们建议确定BAT如何对特定的基因突变和肝脏疾病中可能发生的翻译后修饰敏感。这涉及（1）鉴定关键残基，其（a）解释BAT酶活性，（B）人、小鼠和大鼠之间甘氨酸/牛磺酸底物特异性的显著差异，（c）Cys-235突变为Ser对该蛋白质的酶性质的影响，（d）在阿米什家族中具有胆汁淤积和其他肝胆疾病症状的儿童中观察到的Met-76至瓦尔突变的影响，和（e）使用H-D交换/质谱法，每种突变对BAT结构的影响;（2）使用生物化学和分子生物学方法，控制BAT的过氧化物酶体定位;胆汁淤积性和炎症性肝病中产生的活性氧和活性氮对BAT活性的影响（在体外、肝细胞和动物模型中建模），特别是在半胱氨酸巯基（Cys-235和Cys 372）上，但潜在地在其他基团如酪氨酸和组氨酸残基上。总体而言，这些实验将利用分子生物学、酶生物化学、动物模型和质谱的组合来鉴定BAT的蛋白质修饰，以确定由于肝胆疾病的炎症并发症而在遗传或表观遗传上发生的BA酰胺化缺陷的后果。

项目成果

The enzymatic formation of novel bile acid primary amides.

新型胆汁酸伯酰胺的酶促形成。

• DOI: 10.1006/abbi.1999.1611
• 发表时间: 2000
• 期刊: Archives of biochemistry and biophysics.
• 作者: King3rd,L;Barnes,S;Glufke,U;Henz,ME;Kirk,M;Merkler,KA;Vederas,JC;Wilcox,BJ;Merkler,DJ
• 通讯作者: Merkler,DJ

Bile acid coenzyme A: amino acid N-acyltransferase in the amino acid conjugation of bile acids.

• DOI: 10.1016/s0076-6879(05)00022-4
• 发表时间: 2005
• 期刊: Methods in enzymology
• 作者: E. Shonsey;Mindan K. Sfakianos;Michelle Johnson;Dongning He;C. Falany;J. Falany;D. Merkler;S. Barnes

Quantification and regulation of the subcellular distribution of bile acid coenzyme A:amino acid N-acyltransferase activity in rat liver.

大鼠肝脏中胆汁酸辅酶 A 的亚细胞分布的定量和调节：氨基酸 N-酰基转移酶活性。

• DOI: 10.1194/jlr.m600472-jlr200
• 发表时间: 2007
• 期刊: Journal of lipid research
• 影响因子: 6.5
• 作者: Styles,NathanA;Falany,JosieL;Barnes,Stephen;Falany,CharlesN
• 通讯作者: Falany,CharlesN

Purification and characterization of a rat liver bile acid coenzyme A ligase from rat liver microsomes.

从大鼠肝微粒体中纯化和表征大鼠肝胆汁酸辅酶 A 连接酶。

• DOI: 10.1006/abbi.1997.0391
• 发表时间: 1997
• 期刊: Archives of biochemistry and biophysics.
• 作者: Wheeler,JB;Shaw,DR;Barnes,S
• 通讯作者: Barnes,S

Inactivation of human liver bile acid CoA:amino acid N-acyltransferase by the electrophilic lipid, 4-hydroxynonenal.

亲电脂质 4-羟基壬烯醛可使人肝胆汁酸 CoA：氨基酸 N-酰基转移酶失活。

• DOI: 10.1194/jlr.m700208-jlr200
• 发表时间: 2008
• 期刊: Journal of lipid research
• 影响因子: 6.5
• 作者: Shonsey,EM;Eliuk,SM;Johnson,MS;Barnes,S;Falany,CN;Darley-Usmar,VM;Renfrow,MB
• 通讯作者: Renfrow,MB