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.

Immunocytochemical localization of rat intestinal 15 kDa protein, a member of cytoplasmic fatty acid-binding proteins.

Abstract: Rat intestinal 15 kDa protein (I-15P) is a member of the family of cytoplasmic fatty acid-binding proteins. Using a specific antiserum against I-15P, we studied the tissue distribution and subcellular localization of this protein in the entire rat body. By immunoblot analysis of cytosolic proteins, I-15P was detected not only in the distal portion of small intestine but also in the ovary and adrenal gland. Immunohistochemically, I-15P was localized to the absorptive epithelial cells as well as a subpopulation of enterochromaffin cells in the intestine, the lutein cells in the ovary, and subpopulations of cortical cells in the adrenal gland. Furthermore, I-15P-like immunoreactivity was also demonstrated in the surface mucous cells of stomach and the granular convoluted tubule cells of submandibular gland. Immuno-electron microscopy showed that the immunoreactivity was confined to the cytoplasmic matrix region, except in the enterochromaffin cells and granular convoluted tubule cells, where it was localized in the secretory granules. The present findings suggest that I-15P plays a role in the cellular metabolism of steroids.© Willey-Liss, Inc.

Properties and physiological significance of fatty acid binding proteins

Abstract: Publisher Summary This chapter discusses the properties and physiological significance of fatty acid binding properties. Fatty acid binding proteins (FABP) are found in many tissues of many different organisms, which include mammals, fish, birds, and insects. All FABPs are members of a large multigene family called intracellular lipid binding proteins (iLBPs) with various functions in the transport and metabolism of their ligand fatty acids and other lipophilic ligands. There are different roles in different cells, tissues, and organisms may vary, common features become apparent in the context of metabolic tasks and conditions. The purpose of this chapter is to summarize current knowledge about these proteins, and to provide insight into their roles in different organisms. FABPs are expressed in vertebrate and invertebrate species. Pertaining to the latter, two FABPs are expressed in the midgut of the tobacco hornworm and believed to be involved in lipid digestion. The FABP from the flight muscle of locusts is especially well characterized. The chapter also explains structure and conformation of FABPs and their ligands.

Purification and characterization of fatty acid-binding protein from human placenta.

Abstract: Purification of a cytosolic fatty acid-binding protein (FABP) from developing human placenta has been achieved, and its role in modulating the inhibition of human placental glucose-6-phosphate dehydrogenase (G6PD) by palmitoyl-CoA (PAL-CoA) has been studied. FABP was resolved into three peaks, viz. DE-I, DE-II and DE-III, by DEAE cellulose chromatography. DE-I was almost lipid-free. Presence of endogenous fatty acids in DE-II and DE-III was detected by thin layer chromatography (TLC). Fatty acids were the only detectable lipid component in these fractions. Gas liquid chromatography (GLC) analysis revealed that DE-II binds long chain saturated and unsaturated fatty acids nonspecifically, whereas DE-III is mainly an arachidonic acid carrier. Each of these fractions, viz. DE-I, DE-II and DE-III, has a molecular weight of 14,200 Daltons. Ouchterlony double immunodiffusion studies have confirmed the immunochemical identity of these three fractions of placental FABP. Separation in ion exchanger may be due to their different isoelectric points and varied types of binding affinities. Human placental G6PD was inhibited 50% by 0.03 mM PAL-CoA. The DE-II fraction of FABP enhanced the activity of G6PD in the absence of added PAL-CoA and protected against PAL-CoA inhibition of the enzyme. Such a modulating effect of FABP in this inhibition is attributable to binding of long chain acyl-CoA rather than to a direct effect of FABP on the enzyme itself.