CGI-58/ABHD5 is a coenzyme A-dependent lysophosphatidic acid acyltransferase
摘要:
Mutations in human CGI-58/ABHD5 cause Chanarin-Dorfman syndrome (CDS), characterized by excessive storage of triacylglycerol in tissues. CGI-58 is an alpha/beta-hydrolase fold enzyme expressed in all vertebrates. The carboxyl terminus includes a highly conserved consensus sequence (HXXXXD) for acyltransferase activity. Mouse CGI-58 was expressed in Escherichia coli as a fusion protein with two amino terminal 6-histidine tags. Recombinant CGI-58 displayed acyl-CoA-dependent acyltransferase activity to lysophosphatidic acid, but not to other lysophospholipid or neutral glycerolipid acceptors. Production of phosphatidic acid increased with time and increasing concentrations of recombinant CGI-58 and was optimal between pH 7.0 and 8.5. The enzyme showed saturation kinetics with respect to 1-oleoyl-lysophosphatidic acid and oleoyl-CoA and preference for arachidonoyl-CoA and oleoyl-CoA. The enzyme showed slight preference for 1-oleoyl lysophosphatidic acid over 1-palmitoyl, 1-stearoyl, or 1-arachidonoyl lysophosphatidic acid. Recombinant CGI-58 showed intrinsic fluorescence for tryptophan that was quenched by the addition of 1-oleoyl-lysophosphatidic acid, oleoyl-CoA, arachidonoyl-CoA, and palmitoyl-CoA, but not by lysophosphatidyl choline. Expression of CGI-58 in fibroblasts from humans with CDS increased the incorporation of radiolabeled fatty acids released from the lipolysis of stored triacylglycerols into phospholipids. CGI-58 is a CoA-dependent lysophosphatidic acid acyltransferase that channels fatty acids released from the hydrolysis of stored triacylglycerols into phospholipids.-Montero-Moran, G., J. M. Caviglia, D. McMahon, A. Rothenberg, V. Suramanian, Z. Xu, S. Lara-Gonzalez, J. Storch, G. M. Carman, and D. L. Brasaemle. CGI-58/ABHD5 is a coenzyme A-dependent lysophosphatidic acid acyltransferase. J. Lipid Res. 2010. 51: 709-719.
Lipidic polyketides: We examined the in vitro reactions catalyzed by RpsA, a bacterial typeIIIpolyketidesynthase (PKS) from Rhodospirillum centenum. RpsA is the first typeIII PKS shown to be able to efficiently accept two molecules of extender methylmalonyl‐CoA and to synthesize tetraketide compounds through aldol condensation induced by methine proton abstraction.
Recombinant DNA techniques are used to produce oleaginous recombinant cells that produce triglyceride oils having desired fatty acid profiles and regiospecific or stereospecific profiles. Genes manipulated include those encoding stearoyl-ACP desaturase, delta 12 fatty acid desaturase, acyl-ACP thioesterase, ketoacyl-ACP synthase, and lysophosphatidic acid acyltransferase. The oil produced can have enhanced oxidative or thermal stability, or can be useful as a frying oil, shortening, roll-in shortening, tempering fat, cocoa butter replacement, as a lubricant, or as a feedstock for various chemical processes. The fatty acid profile can be enriched in midchain profiles or the oil can be enriched in triglycerides of the saturated-unsaturated-saturated type.
DNA 重组技术用于生产含油重组细胞,这些细胞能生产出具有所需脂肪酸特征和区域特异性或立体特异性特征的甘油三酯油。操纵的基因包括编码硬脂酰-ACP 去饱和酶、δ 12 脂肪酸去饱和酶、酰基-ACP 硫代酯酶、酮酰-ACP 合酶和溶血磷脂酸酰基转移酶的基因。生产出的油可增强氧化稳定性或热稳定性,或可用作煎炸油、起酥油、轧制起酥油、调和脂肪、可可脂替代物、润滑剂或各种化学工艺的原料。脂肪酸谱可以富含中链脂肪酸谱,或者油可以富含饱和-不饱和-饱和型甘油三酯。
Structuring fats and methods of producing structuring fats
申请人:Corbion Biotech, Inc.
公开号:US10287613B2
公开(公告)日:2019-05-14
Recombinant DNA techniques are used to produce oleaginous recombinant cells that produce triglyceride oils having desired fatty acid profiles and regiospecific or stereospecific profiles. Genes manipulated include those encoding stearoyl-ACP desturase, delta 12 fatty acid desaturase, acyl-ACP thioesterase, ketoacyl-ACP synthase, and lysophosphatidic acid acyltransferase. The oil produced can have enhanced oxidative or thermal stability, or can be useful as a frying oil, shortening, roll-in shortening, tempering fat, cocoa butter replacement, as a lubricant, or as a feedstock for various chemical processes. The fatty acid profile can be enriched in midchain profiles or the oil can be enriched in triglycerides of the saturated-unsaturated-saturated type.
DNA 重组技术用于生产含油重组细胞,这些细胞可生产出具有所需脂肪酸特征和区域特异性或立体特异性特征的甘油三酯油。操纵的基因包括编码硬脂酰-ACP 去嘌呤酶、δ 12 脂肪酸去饱和酶、酰基-ACP 硫代酯酶、酮酰-ACP 合酶和溶血磷脂酸酰基转移酶的基因。生产出的油可增强氧化稳定性或热稳定性,或可用作煎炸油、起酥油、轧制起酥油、调和脂肪、可可脂替代物、润滑剂或各种化学工艺的原料。脂肪酸谱可以富含中链脂肪酸谱,或者油可以富含饱和-不饱和-饱和型甘油三酯。
Alkylresorcylic acid synthesis by type III polyketide synthases from rice Oryza sativa
Alkylresorcinols, produced by various plants, bacteria, and fungi, are bioactive compounds possessing beneficial activities for human health, such as anti-cancer activity. In rice, they accumulate in seedlings, contributing to protection against fungi. Alkylresorcylic acids, which are carboxylated forms of alkylresorcinols, are unstable compounds and decarboxylate readily to yield alkylresorcinols. Genome mining of the rice Oryza sativa identified two type III polyketide synthases, named ARAS1 (alkylresorcylic acid synthase) and ARAS2, that catalyze the formation of alkylresorcylic acids. Both enzymes condensed fatty acyl-CoAs with three C-2 units from malonyl-CoA and cyclized the resulting tetraketide intermediates via intramolecular C-2 to C-7 aldol condensation. The alkylresorcylic acids thus produced were released from the enzyme and decarboxylated non-enzymatically to yield alkylresorcinols. This is the first report on a plant type III polyketide synthase that produces tetraketide alkylresorcylic acids as major products. (C)2010 Published by Elsevier Ltd.