脂肪细胞型脂肪酸结合蛋白的研究进展

脂肪细胞型脂肪酸结合蛋白(adipocyte fatty acid binding protein,AFABP/aP2)作为脂肪酸结合蛋白(FABPS)超家族成员之一,广泛存在于各种正常的组织细胞中,参与脂肪酸贮存,运输与降解等过程。近年来,对脂肪细胞型脂肪酸结合蛋白的研究已成为热点,本文就其主要特征及其与各类疾病的关系作一简要综述。     

糖尿病和动脉粥样硬化的潜在靶标——FABP4（aP2）

脂肪细胞型脂肪酸结合蛋白（A-FABP／FABP4／aP2／ALBP）作为脂肪酸结合蛋白家族中的一员,在脂肪细胞和巨噬细胞中高表达。在鼠及人的肥胖个体中FABP4表达均增加。FABP4基因缺陷可改善胰岛素抵抗,并抑制动脉粥样硬化的发生发展。FABP4抑制剂减小了动物体内动脉硬化斑块的大小且提高了胰岛素敏感性。FABP4已经成为治疗糖尿病和动脉粥样硬化的重要潜在靶标。     

动物FABP基因家族研究进展及育种应用探讨

脂肪酸结合蛋白家族(FABPs)是脂质结合蛋白超家族成员,它们广泛存在于哺乳动物的小肠、肝、心、脑、骨骼肌等多种细胞内。在调节细胞内长链脂肪酸(LCFA)的摄取、转运和代谢等生理活动发挥着重要的作用。本研究对几种常见的脂肪酸结合蛋白,如心脏型脂肪酸结合蛋白(H-FABP)、脂肪细胞型脂肪酸结合蛋白(A-FABP)、肠型脂肪酸结合蛋白(I-FABP)基因的基因多态性、在动物育种上的应用等相关研究进展进行了阐述,为利用FABPs基因改良和提高畜产品品质提供参考。     

鸡脂肪酸结合蛋白基因的克隆和测序分析

根据哺乳动物脂肪酸结合蛋白基因序列设计一对引物对鸡基因组进行PCR扩增,将163bp扩增片段进行克隆和测序,并与猪的脂肪酸结合蛋白（fatty acid binding protein,FABP）基因序列进行同源性比较。该基因因片段与猪的心脏脂肪酸结合蛋白（heart fatty acid binding protein,H-FABP）基因有68%的同源性,与猪的脂肪型脂肪酸结合蛋白（adipocyte fatty acid binding protein,A-FABP）基因有75%的同源性,演绎成氨基酸之后与猪的脂肪型脂肪酸结合蛋白相应的氨基酸有75%的同源性。Northern结果表明该基因只在脂肪组织中表达。     

猪I-FABP基因的分子克隆与组织特异性表达分析

小肠型脂肪酸结合蛋白对长链脂肪酸具有高度的亲和力,参与脂肪酸的吸收和细胞内转运。利用cDNA末端快速扩增（RACE）技术并结合同源克隆策略,克隆到了编码猪小肠型脂肪酸结合蛋白基因（I-FABP）的全长cDNA序列（GenBank接受号：AY960624）,并对系统发育关系等进行了生物信息学分析。猪I-FABP基因的cDNA序列全长614 bp,其中包括399bp的开放式读码框（ORF）,43bp的5’末端非编码区（5’URT）和172bp的3’末端非编码区（3’URT）,编码132个氨基酸残基蛋白,在氨基酸水半上与其他物种的I-FABP具有高度的同源性。以邻接法（Neigbor-Joining,NJ）所构建的系统发育关系表明,猪I-FABP与其他物种的,I-FABP属于同一类群,且与人的遗传距离最近。Northern杂交和半定量RT—PCR分析发现,猪I-FABP在猪体组织中出现约620bp大小的转录本,且在猪体组织中广泛存在,但在小肠组织中表达量最为丰富。     

槟榔碱对3T3-L1脂肪细胞脂代谢的影响

目的：观察槟榔碱对3T3-L1脂肪细胞脂代谢的影响并探讨其可能机制。方法：采用经典的"鸡尾酒"法诱导3T3-L1前脂肪细胞分化成熟,随后用不同浓度的槟榔碱（0、25、50、100 μmol/L）处理成熟脂肪细胞72 h。72 h后,四甲基偶氮唑盐（MTT）法检测细胞的活性;油红O染色观察胞浆内脂滴情况;Western blot检测脂肪酸合成酶（FAS）、甘油三酯脂肪酶（ATGL）、激素敏感性脂肪酶（HSL）蛋白表达。结果：诱导分化成熟的脂肪细胞胞浆内可见大量脂滴;MTT显示：0~100 μmol/L槟榔碱对脂肪细胞活力无显著影响;油红O染色后脂质含量测定结果表明槟榔碱能减少成熟脂肪细胞中脂质含量;Western blot结果显示：与0 μmol/L组（对照组）相比,槟榔碱可显著降低脂肪细胞内FAS的蛋白表达,增加ATGL和HSL的蛋白表达;其中以50 μmol/L组最为显著。结论：槟榔碱使脂肪细胞脂解增强,可能与降低脂质合成关键酶FAS的表达,增加脂质分解代谢关键酶ATGL和HSL的表达有关。     

克隆用于干癣病态分析的脂肪酸结合蛋白的cDNA

新泻大学医学部教授小野辉夫等小组从小鼠皮肤中分离出新的脂肪酸结合蛋白(C-FABP),并克隆了cDNA。C-FABP与人干癣病表皮细胞大量表达的脂肪酸结合蛋白(PA-FABP)的同源性高达81.5％。C-FABP的表达可能与干癣病有某种关系。在大阪召开的第67届日本生化学会上发表了该项成果。 得到的C-FABP的cDNA编码了135个氨基酸,C-FABP是分子量约15000的蛋白。目前已得知FABP家族有心肌型、脂肪细胞型、髓磷脂型等多种,它们与这次新分离的C-FABP的同源性分别为48％、52.6％、54.1％。C-FABP参与静电性结合,含有在FABP家族中保守性强的精氨酸残基。但含     

肌肉脂肪酸转运膜蛋白及其相互关系

肌肉（骨骼肌）组织对脂肪酸的利用水平是影响机体能量稳态的关键因素.肌肉摄取的长链脂肪酸(long chain fatty acids,LCFAs)主要依赖细胞膜载体蛋白协助的跨膜转运过程.近年来,一系列与脂肪酸转运相关的膜蛋白被相继克隆鉴定,其中在肌肉中大量表达的有脂肪酸转运蛋白-1（fatty acid transport protein-1,FATP-1）、膜脂肪酸结合蛋白（plasma membrane fatty acid binding protein,FABPpm）、脂肪酸转位酶（fatty acid translocase,FAT/CD36）和小窝蛋白-1（caveolin-1）.研究上述肌肉脂肪酸转运膜蛋白的结构功能、调控机制及相互关系,可能为肥胖等脂类代谢紊乱疾病的诊治提供新的手段.     

肝型脂肪酸结合蛋白研究进展

肝型脂肪酸结合蛋白(liver-type fatty acid binding protein,L-FABP,FABPI)是脂肪酸结合蛋白家族的成员之一,主要在肝脏、小肠、肾脏及胰腺等组织细胞中有表达.研究发现,L-FABP与脂肪酸的摄取、转运、代谢调节有关.近年研究表明,肝型脂肪酸结合蛋白(L-FABP)与肿瘤、肾脏疾病、脂肪肝、肥胖、糖尿病等多种疾病的发生发展密切相关.本文就肝型脂肪酸结合蛋白的分子结构、功能以及与疾病的关系作一综述.     

心肌型脂肪酸结合蛋白胶体金检测试纸条的制备和初步应用

目的应用胶体金免疫层析法制备检测全血或血清样本中心肌型脂肪酸结合蛋白（H-FABP）的检测试纸条,用于急性心肌梗塞（AMI）的早期辅助诊断。方法采用柠檬酸三钠还原法制备胶体金,标记鼠抗心肌型脂肪酸结合蛋白单克隆抗体,喷于玻璃纤维膜上制成胶体金结合物垫,将另一株鼠抗心肌型脂肪酸结合蛋白单克隆抗体和抗鼠二抗分别包被检测线和质控线,组装成试纸条进行灵敏性、特异性、精密性、稳定性及临床样品检测。结果该试纸条的检测灵敏度为10ng／mL,15min内可判定结果;与肌钙蛋白I、C反应蛋白、肌酸激酶、人心肌肌红蛋白无交叉反应。检测240份临床标本,与临床诊断结果进行配对分析,阳性符合率95．83％、阴性符合率100％、总符合率97．92％。结论制备的H-FABP检测试纸条有良好的灵敏性、特异性,可用于早期AMI的辅助诊断。     

Relationship between fatty acid binding proteins,acetyl-CoA formation and fatty acid synthesis in developing human placenta

The relationship between fatty acid binding proteins, ATP citrate lyase activity and fatty acid synthesis in developing human placenta has been studied. Fatty acid binding proteins reverse the inhibitory efect of palmitoyl-CoA and oleate on ATP citrate lyase and fatty acid synthesis. In the absence of these inhibitors fatty acid binding proteins activate ATP citrate lyase and stimulate [ 1-¹⁴ C] acetate incorporation into placental fatty acids indicating binding of endogenous inhibitors by these proteins. Thus these proteins regulate the supply of acetyl-CoA as well as the synthesis of fatty acids from that substrates. As gestation proceeds and more lipids are required by the developing placenta fatty acid binding protein content, activity of ATP citrate lyase and rate of fatty acid synthesis increase indicating a cause and efect relationship between the demand of lipids and supply of precursor fatty acids during human placental development.     

Relationship between glycerol-3-phosphate dehydrogenase,fatty acid synthase and fatty acid binding proteins in developing human placenta

The activities of the enzymes glycerol-3-phosphate dehydrogenase and fatty acid synthase are inhibited by palmitoyl-coenzyme A and oleate. The two isoforms of fatty acid binding proteins (PI 6.9 and PI 5.4) enhance the activities of glycerol-3-phosphate dehydrogenase and fatty acid synthase in the absence of palmitoyl-coenzyme A or oleate and also protect them against palmitoyl-coenzyme A or oleate inhibition. Levels of fatty acid binding proteins, the activities of the enzymes fatty acid synthase and glycerol-3-phosphate dehydrogenase increase with gestation showing a peak at term. However, the activity of fatty acid synthase showed the same trend up to the 30th week of gestation and then declined slightly at term. With the advancement of pregnancy when more lipids are required for the developing placenta, fatty acid binding proteins supply more fatty acids and glycerol-3-phosphate for the synthesis of lipids. Thus a correlation exists between glycerol-3-phosphate dehydrogenase, fatty acid synthase and fatty acid binding proteins in developing human placenta.     

Study on fatty acid binding by proteins in yeast. Dissimilar results in Saccharomyces cerevisiae and Yarrowia lipolytica.

1. The presence of soluble proteins with fatty acid binding activity was investigated in cell-free extracts from Saccharomyces cerevisiae and Yarrowia lipolytica cultures. 2. No significant fatty acid binding by proteins was detected in S. cerevisiae, even when grown on a fatty acid-rich medium, thus indicating that such proteins are not essential to fatty acid metabolism. 3. An inducible fatty acid binding protein (K0.5 = 3-4 microM) was found in Y. lipolytica which had grown on a minimal medium with palmitate as the sole source of carbon and energy. 4. The relative molecular mass of this protein was 100,000 as inferred from Sephacryl S-200 gel filtration.     

Potent and selective biphenyl azole inhibitors of adipocyte fatty acid binding protein (aFABP)

Herein we report the first disclosure of biphenyl azoles that are nanomolar binders of adipocyte fatty acid binding protein (aFABP or aP2) with up to thousand-fold selectivity against muscle fatty acid binding protein and epidermal fatty acid binding protein. In addition a new radio-ligand to determine binding against the three fatty acid binding proteins was also synthesized.     

The role of fatty acid binding proteins in metabolic syndrome and atherosclerosis

PURPOSE OF REVIEW: The global prevalence of obesity is increasing epidemically. Obesity causes an array of health problems, reduces life expectancy, and costs over US dollar 100 billion annually. More than a quarter of the population suffers from an aggregation of co-morbidities, including obesity, atherosclerosis, insulin resistance, dyslipidemias, coagulopathies, hypertension, and a pro-inflammatory state known as the metabolic syndrome. Patients with metabolic syndrome have high risk of atherosclerosis as well as type 2 diabetes and other health problems. Like obesity, atherosclerosis has very limited therapeutic options. RECENT FINDINGS: Fatty acid binding proteins integrate metabolic and immune responses and link the inflammatory and lipid-mediated pathways that are critical in the metabolic syndrome. This review will highlight recent studies on fatty acid binding protein-deficient models and several fatty acid binding protein-mediated pathways specifically modified in macrophages, cells that are paramount to the initiation and persistence of cardiovascular lesions. SUMMARY: Adipocyte/macrophage fatty acid binding proteins, aP2 and mal1, act at the interface of metabolic and inflammatory pathways. These fatty acid binding proteins are involved in the formation of atherosclerosis predominantly through the direct modification of macrophage cholesterol trafficking and inflammatory responses. In addition to atherosclerosis, these fatty acid binding proteins also exert a dramatic impact on obesity, insulin resistance, type 2 diabetes and fatty liver disease. The creation of pharmacological agents to modify fatty acid binding protein function will provide tissue or cell-type-specific control of these lipid signaling pathways, inflammatory responses, atherosclerosis, and the other components of the metabolic syndrome, therefore offering a new class of multi-indication therapeutic agents.     

Interaction of fatty acids with recombinant rat intestinal and liver fatty acid-binding proteins

Intestinal enterocytes contain two homologous fatty acid-binding proteins, intestinal fatty acid-binding protein (I-FABP)2 and liver fatty acid-binding protein (L-FABP). Since the functional basis for this multiplicity is not known, the fatty acid-binding specificity of recombinant forms of both rat I-FABP and rat L-FABP was examined. A systematic comparative analysis of the 18 carbon chain length fatty acid binding parameters, using both radiolabeled (stearic, oleic, and linoleic) and fluorescent (trans-parinaric and cis-parinaric) fatty acids, was undertaken. Results obtained with a classical Lipidex-1000 binding assay, which requires separation of bound from free fatty acid, were confirmed with a fluorescent fatty acid-binding assay not requiring separation of bound and unbound ligand. Depending on the nature of the fatty acid ligand, I-FABP bound fatty acid had dissociation constants between 0.2 and 3.1 microM and a consistent 1:1 molar ratio. The dissociation constants for L-FABP bound fatty acids ranged between 0.9 and 2.6 microM and the protein bound up to 2 mol fatty acid per mole of protein. Both fatty acid-binding proteins exhibited relatively higher affinity for unsaturated fatty acids as compared to saturated fatty acids of the same chain length. cis-Parinaric acid or trans-parinaric acid (each containing four double bonds) bound to L-FABP and I-FABP were displaced in a competitive manner by non-fluorescent fatty acid. Hill plots of the binding of cis- and trans- parinaric acid to L-FABP showed that the binding affinities of the two sites were very similar and did not exhibit cooperativity. The lack of fluorescence self-quenching upon binding 2 mol of either trans- or cis-parinaric acid/mol L-FABP is consistent with the presence of two binding sites with dissimilar orientation in the L-FABP. Thus, the difference in binding capacity between I-FABP and L-FABP predicts a structurally different binding site or sites.     

Binding of acyl-CoA to liver fatty acid binding protein: effect on acyl-CoA synthesis

The ability of purified rat liver and heart fatty acid binding proteins to bind oleoyl-CoA and modulate acyl-CoA synthesis by microsomal membranes was investigated. Using binding assays employing either Lipidex 1000 or multilamellar liposomes to sequester unbound ligand, rat liver but not rat heart fatty acid binding protein was shown to bind radiolabeled acyl CoA. Binding studies suggest that liver fatty acid binding protein has a single binding site acyl-CoA which is separate from the two binding sites for fatty acids. Experiments were then performed to determine how binding may influence acyl-CoA metabolism by liver microsomes or heart sarcoplasmic reticulum. Using liposomes as fatty acid donors, liver fatty acid binding protein stimulated acyl-CoA production, whereas that from heart did not stimulate production over control values. 14C-labeled fatty acid-fatty acid binding protein complexes were prepared, incubated with membranes, and acyl-CoA synthetase activity was determined. Up to 70% of the fatty acid could be converted to acyl-CoA in the presence of liver fatty acid binding protein but in the presence of heart fatty acid binding protein, only 45% of the fatty acid was converted. Liver but not heart fatty acid binding protein bound the acyl-CoA formed and removed it from the membranes. The amount of product formed was not changed by additional membrane, enzyme cofactors, or incubation time. Additional liver fatty acid binding protein was the only factor found that stimulated product formation. Acyl-CoA hydrolase activity was also shown in the absence of ATP and CoA. These studies suggest that liver fatty acid binding protein can increase the amount of acyl-CoA by binding this ligand, thereby removing it from the membrane and possibly aiding transport within the cell.     

Alteration of the binding specificity of cellular retinol-binding protein II by site-directed mutagenesis.

Rat cellular retinol-binding protein II (CRBP II) is an abundant 134-residue intestinal protein that binds all-trans-retinol and all-trans-retinal. It belongs to a family of homologous, 15-kDa cytoplasmic proteins that bind hydrophobic ligands in a noncovalent fashion. These binding proteins include a number of proteins that bind long chain fatty acids. X-ray analyses of the structure of two family members, rat intestinal fatty acid-binding protein and bovine myelin P2 protein, indicate that they have a high degree of conformational similarity and that the carboxylate group of their bound fatty acid interacts with a delta-guanidium group of at least 1 of 2 "buried" arginine residues. These 2 Arg residues are conserved in other family members that bind long chain fatty acids and in cellular retinoic acid-binding protein, but are replaced by Gln109 and Gln129 in CRBP II. We have genetically engineered two amino acid substitutions in CRBP II: 1) Gln109 to Arg and 2) Gln129 to Arg. The purified Escherichia coli-derived CRBP II mutant proteins were analyzed by fluorescence and nuclear magnetic resonance spectroscopy. Both mutants exhibit markedly decreased binding of all-trans-retinol and all-trans-retinaldehyde, but no increased binding of all-trans-retinoic acid. Arg substitution for Gln109 but not for Gln129 produces a dramatic increase in palmitate binding activity. Analysis of the endogenous fatty acids associated with the purified E. coli-derived proteins revealed that E. coli-derived intestinal fatty acid binding protein and the Arg109 CRBP II mutant are complexed with endogenous fatty acids in a qualitatively and quantitatively similar manner. These results provide evidence that this internal Arg may play an important role in the binding of long chain fatty acids by members of this protein family.