Fatty acid-binding protein

About: Fatty acid-binding protein is a research topic. Over the lifetime, 1721 publications have been published within this topic receiving 81530 citations. The topic is also known as: FABP.

Long-chain polyunsaturated fatty acid accretion in brain.

Abstract: Brain is highly enriched in long-chain polyunsaturated fatty acids (PUFAs), particularly arachidonic acid and docosahexaenoic acid, which play important roles in brain structural and biologic functions. Plasma transport, in the form of free fatty acids or esterified FAs in lysophosphatidylcholine and lipoproteins, and de-novo synthesis contribute to brain accretion of long-chain PUFAs. Transport of long-chain PUFAs from plasma may play important roles because of the limited ability of brain to synthesize long-chain PUFAs, in the face of high demand for them. Although several proteins involved in facilitated fatty acid transport (e.g. fatty acid transport protein, fatty acid binding protein and very-long-chain acyl-coenzyme A synthetase) have been found in brain, their roles in fatty acid accumulation in brain are poorly defined. The primary pathways that are involved in long-chain PUFA accumulation in brain may vary according to brain region and developmental stage.

Differential gene expression of fatty acid binding proteins during porcine adipogenesis

Abstract: Four different subtypes of fatty acid binding proteins i.e. liver-type FABP1, heart/muscle-type FABP3, adipocyte-type FABP4 and epithelial/epidermal-type FABP5 are expressed in adipose tissue. However, only the regulatory role of FABP4 in adipogenesis has been thoroughly investigated. To increase the knowledge on possible roles of these FABP subtypes in preadipocyte differentiation, gene expression patterns were examined during adipogenesis in pig (Sus scrofa). FABP1 expression was induced in proliferating cells, whereas FABP3, FABP4 and FABP5 expression increased throughout preadipocyte differentiation. Interestingly, the FABP4 and FABP5 expression increased early in the differentiation, followed by FABP3 later in the differentiation process. This indicates a role of FABP4 and FABP5 in intracellular fatty acid transport during initiation of differentiation, whereas, FABP3 likely is involved in the transport of fatty acids during intermediate stages of adipogenesis. In this study we demonstrate that FABP3, FABP4 and FABP5 expression is correlated with that of the peroxisome proliferator-activated receptors alpha and gamma (PPARA and PPARG). Altogether, this suggests a role of FABP1 during cell proliferation, whereas a coordinated expression of FABP3, FABP4 and FABP5 together with that of PPARA, PPARG1 and PPARG2 might be critical for the metabolic regulation during porcine adipogenesis.

Seasonal proteomic changes reveal molecular adaptations to preserve and replenish liver proteins during ground squirrel hibernation

Abstract: Hibernators are unique among mammals in their ability to survive extended periods of time with core body temperatures near freezing and with dramatically reduced heart, respiratory, and metabolic rates in a state known as torpor. To gain insight into the molecular events underlying this remarkable physiological phenotype, we applied a proteomic screening approach to identify liver proteins that differ between the summer active (SA) and the entrance (Ent) phase of winter hibernation in 13-lined ground squirrels. The relative abundance of 1,600 protein spots separated on two-dimensional gels was quantitatively determined using fluorescence difference gel electrophoresis, and 74 unique proteins exhibiting significant differences between the two states were identified using liquid chromatography followed by tandem mass spectrometry (LC-MS/MS). Proteins elevated in Ent hibernators included liver fatty acid-binding protein, fatty acid transporter, and 3-hydroxy-3-methylglutaryl-CoA synthase, which support the known metabolic fuel switch to lipid and ketone body utilization in winter. Several proteins involved in protein stability and protein folding were also elevated in the Ent phase, consistent with previous findings. In contrast to transcript screening results, there was a surprising increase in the abundance of proteins involved in protein synthesis during Ent hibernation, including several initiation and elongation factors. This finding, coupled with decreased abundance of numerous proteins involved in amino acid and nitrogen metabolism, supports the intriguing hypothesis that the mechanism of protein preservation and resynthesis is used by hibernating ground squirrels to help avoid nitrogen toxicity and ensure preservation of essential amino acids throughout the long winter fast.

In vitro inhibition of insulin-degrading enzyme by long-chain fatty acids and their coenzyme A thioesters.

Abstract: Insulin-degrading enzyme is responsible for initiating insulin degradation in cells, but little is known about the factors controlling its activity. Because obesity and high levels of free fatty acids decrease insulin clearance, we examined the effect of some common free fatty acids and their acyl-coenzyme A thioesters on insulin-degrading enzyme partially purified from the livers of male Sprague Dawley rats. Octanoic acid (C8:0) had no effect on activity. Long-chain free fatty acids (C16-C20) inhibited between 50% and 90% of the insulin degradation with IC(50) values in the range of 10-50 micro M. In general, the corresponding acyl-coenzyme A thioesters had lower IC(50) values and were slightly more efficacious. (125)I-insulin cross-linking studies showed free fatty acids did not inhibit hormone binding to insulin-degrading enzyme. Kinetic analysis showed a noncompetitive type of inhibition. Furthermore, fatty acids eliminated the ability of insulin to inhibit the proteasome. These results suggest that when intracellular long-chain fatty acid concentrations are elevated, they may act directly on insulin-degrading enzyme to decrease insulin metabolism and alter insulin action in intact cells. This mechanism may contribute to the hyperinsulinemia and insulin resistance seen with elevated fatty acids and obesity.