Protein fatty acid binding

There is a second family of small lipid-binding proteins, the P2 family, which include among others cellular retinol- and fatty acid-binding proteins as well as a protein, P2, from myelin in the peripheral nervous system. However, members of this second family have ten antiparallel p strands in their barrels compared with the eight strands found in the barrels of the RBP superfamily. Members of the P2 family show no amino acid sequence homology to members of the RBP superfamily. Nevertheless, their three-dimensional structures have similar architecture and topology, being up-and-down P barrels. 

Sacchettini, J.C., et al. Refined apoprotein stmcture of rat intestinal fatty acid binding protein produced in Escherichia coli. Proc. Natl. Acad. Sci. USA 86 7736-7740, 1989. 

Actual and predicted structures of three domains of intestinal fatty acid binding protein... 

Acetoacetate and /3-hydroxybutyrate are transported through the blood from liver to target organs and tissues, where they are converted to acetyl-CoA (Figure 24.29). Ketone bodies are easily transportable forms of fatty acids that move through the circulatory system without the need for eomplexation with serum albumin and other fatty acid—binding proteins. 

Gene activated Lipoprotein lipase fatty acid transporter protein adipocyte fatty acid binding protein acyl-CoA synthetase malic enzyme GLUT-4 glucose transporter phosphoenolpyruvate carboxykinase... 

Guidon, P.T. Hightower, L.E. (1986). Purification and initial characterization of the 71-kilodalton rat heat-shock protein and its cognate as fatty acid binding proteins. Biochemistry, 25, 3231-9. 

Free fatty acids—also called unesterified (UFA) or non-esterified (NEFA) fatty acids—are fatty acids that are in the unesterified state. In plasma, longer-chain FFA are combined with albumin, and in the cell they are attached to a fatty acid-binding protein, so that in fact they are never really free. Shorter-chain fatty acids are... 

The free fatty acid uptake by tissues is related directly to the plasma free fatty acid concentration, which in turn is determined by the rate of lipolysis in adipose tissue. After dissociation of the fatty acid-albumin complex at the plasma membrane, fatty acids bind to a membrane tty acid transport protein that acts as a transmembrane cotransporter with Na. On entering the cytosol, free fatty acids are bound by intracellular fatty acid-binding proteins. The role of these proteins in intracellular transport is thought to be similar to that of serum albumin in extracellular transport of long-chain fatty acids. 

Kaikans RM, Bass NM, Ockner RK Functions of fatty acid binding proteins. Experientia 1990 46 617. 

The hypothesis of the participation of those cholesterol transporters (NPCILI and ABCAl) in the carotenoid transport remains to be confirmed, especially at the in vivo human scale. If the mechanism by which carotenoids are transported through the intestinal epithelial membrane seems better understood, the mechanism of intracellular carotenoid transport is yet to be elucidated. The fatty acid binding protein (FABP) responsible for the intracellular transport of fatty acids was proposed earlier as a potential transporter for carotenoids. FABP would transport carotenoids from the epithelial cell membrane to the intracellular organelles such as the Golgi apparatus where CMs are formed and assembled, but no data have illustrated this hypothesis yet. 

A. Properties of the Intestinal Fatty Acid Binding Protein. 103... 

The remaining major classes of water-soluble lipid transporter proteins (other than the polyproteins of nematodes see below) come from plants and helminths. Plants possess very small (approximately 9 kDa) helix-rich, fatty-acid-binding proteins, the structures of some of which are known (Lerche and Poulsen, 1998). A recently described class comes from cestodes these are also very small (approximately 8 kDa), presumably intracellular, and helix-rich, and bind anthelmintic drugs in addition to fatty acids (Janssen and Barrett, 1995 Barrett et al., 1997). The only helix-rich small (approximately 14 kDa) lipid transporter from vertebrates is the acetyl-CoA-binding protein (Kragelund et al., 1993). 

Campbell, F.M., Gordan, M.J., Taffasse, S. and Dutta-Roy, A.K. (1995) Plasma membrane fatty acid-binding protein from human placenta identification and characterization. Biochemical and Biophysical Research Communications 209, 1011-1017. 

Coe, N.R. and Bernlohr, D.A. (1998) Physiological properties and functions of intracellular fatty acid-binding proteins. Biochimica et Biophysica Acta 1391, 287-306. 

Corsico, B., Cistola, D.P., Frieden, C. and Storch, J. (1998) The helical domain of intestinal fatty acid binding protein is critical for collisional transfer of fatty acids to phospholipid membranes. Proceedings of the National Academy of Sciences USA 95,12174-12178. 

Herr, F.H., Matarese, V., Bernlohr, D.A. and Storch, J. (1995) Surface lysine residues modulate the collisional transfer of fatty acid from adipocyte fatty acid binding protein to membranes. Biochemistry 34, 11840-11845. 

Hsu, K.-T. and Storch, J. (1996) Fatty acid transfer from liver and intestinal fatty acid-binding proteins to membranes occurs by different mechanisms. Journal of Biological Chemistry 271,13317—13323. 

Kennedy, M.W., Scott, J.C., Lo, S.J., Beauchamp, J. and McManus, D.P. (2000) The Sj-FABPc fatty acid binding protein of the human blood fluke Schistosoma japonicum structural and functional characterisation and unusual solvent exposure of a portal-proximal tryptophan. BiochemicalJournal 349, 377-384. 

Mei, B., Kennedy, M.W., Beauchamp, J., Komuniecki, P.R. and Komuniecki, R. (1997) Secretion of a novel, developmentally regulated fatty acid binding protein into the perivitelline fluid of the parasitic nematode, Ascaris mum. Journal of Biological Chemistry 272, 9933-9941. 

Sacchettini, J.C. and Gordon, J.I. (1993) Rat intestinal fatty acid binding protein a model system for analyzing the forces that can bind fatty acids to proteins. Journal of Biological Chemistry 268, 18399—18402. 

Stewart, J.M. (2000) The cytoplasmic fatty acid binding proteins thirty years and counting. Cellular and Molecular Life Sciences (in press). 

U. Kunz, A. Katerkamp, R. Renneberg, F. Spener, and K. Cammann, Sensing fatty acid binding protein with planar and fiber-optical surface plasmon resonance spectroscopy devices. Sens. Actuators B 32, 149-155 (1996). 

Schnurr et al. [22] showed that rabbit 15-LOX oxidized beef heart submitochondrial particles to form phospholipid-bound hydroperoxy- and keto-polyenoic fatty acids and induced the oxidative modification of membrane proteins. It was also found that the total oxygen uptake significantly exceeded the formation of oxygenated polyenoic acids supposedly due to the formation of hydroxyl radicals by the reaction of ubiquinone with lipid 15-LOX-derived hydroperoxides. However, it is impossible to agree with this proposal because it is known for a long time [23] that quinones cannot catalyze the formation of hydroxyl radicals by the Fenton reaction. Oxidation of intracellular unsaturated acids (for example, linoleic and arachidonic acids) by lipoxygenases can be suppressed by fatty acid binding proteins [24]. 

P2 protein. PNS myelin contains a positively charged protein different from MBP that is referred to as P2 (Mr — 15,000). It is unrelated in sequence to MBP and is a member of a family of cytoplasmic fatty acid binding proteins (FABP) that are present in a variety of cell types [25]. The amount of P2 protein is variable among species, accounting for about 15% of total protein in bovine PNS myelin, 5% in humans and less than 1% in rodents. P2 protein is generally considered a PNS myelin protein but it is expressed in small amounts in CNS myelin sheaths of some species. P2 is an antigen for experimental allergic neuritis, the PNS counterpart of EAE (see Chs 36 and 38). P2 appears to be present in the major dense line of myelin sheaths, where it may play a structural role similar to MBP... 

CNPase 2, 3 cyclic nucleotide 3 -phosphodiesterase FABP fatty acid binding proteins... 

---