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Author

Gourisankar Sa

Bio: Gourisankar Sa is an academic researcher from University of Calcutta. The author has contributed to research in topics: Fatty acid-binding protein & Enzyme. The author has an hindex of 4, co-authored 7 publications receiving 65 citations.

Papers
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Journal ArticleDOI
01 Jun 1988-Lipids
TL;DR: Ouchterlony double immunodiffusion studies have confirmed the immunochemical identity of these three fractions of placental FABP, which revealed that DE-II binds long chain saturated and unsaturated fatty acids nonspecifically, whereas DE-III is mainly an arachidonic acid carrier.
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.

26 citations

Journal ArticleDOI
TL;DR: F fetal liver FABPs play a regulatory role in critical aspects of cellular physiology during human embryogenesis and protect glucose-6-phosphate dehydrogenase from the feed-back inhibition exerted by added palmitoyl-CoA and oleate.

16 citations

Journal ArticleDOI
TL;DR: Defatted lung FABP reverses the inhibitory effect of palmitoyl coenzyme A (CoA) (PAL- CoA) on lung glucose-6-phosphate dehydrogenase (G6PD), a key enzyme of the hexose monophosphate (HMP) shunt pathway in vitro.
Abstract: Fatty acid-binding protein (FABP) was isolated, purified, and characterized from developing human fetal lung cytosol by gel filtration and ion-exchange chromatography. FABP exists in three immunochemically identical forms, DE-I, DE-II, and DE-III, having Mr 15,200 ± 200 each and isoelectric pH 7.8, 6.9, and 5.4, respectively. DE-I is almost lipid-free, DE-II binds mainly long-chain unsaturated fatty acids, and DE-III is an arachi-donic acid carrier. One mole of DE-II and DE-III each binds 1 mol of fatty acids noncov-alently. Concentrations of all these FABPs increase gradually from early gestation to term. Defatted lung FABP reverses the inhibitory effect of palmitoyl coenzyme A (CoA) (PAL-CoA) on lung glucose-6-phosphate dehydrogenase (G6PD), a key enzyme of the hexose monophosphate (HMP) shunt pathway. This protein when added alone activates the enzyme, suggesting that the original submaximal activity is probably due to the presence of endogenous long-chain fatty acyl CoA esters in the cytosols. As FABP...

12 citations

Journal Article
TL;DR: Role of fatty acid binding proteins (FABPs) in modulating inhibition of human placental malate dehydrogenase by palmitoyl-CoA and oleate has been studied and a modulatory effect of FABP may be due to the binding of long chain fatty acyl- coA or fatty acid.
Abstract: Role of fatty acid binding proteins (FABPs) in modulating inhibition of human placental malate dehydrogenase by palmitoyl-CoA and oleate has been studied Activity of human placental cytosolic malate dehydrogenase is detected throughout the gestation, showing a peak at midgestation (20-25 weeks) Inhibition (50%) of the enzyme activity is obtained by 20 microM palmitoyl-CoA or 35 microM oleate FABPs enhance the activity of malate dehydrogenase in absence of palmitoyl-CoA or oleate and also protect against palmitoyl-CoA or oleate inhibition Such a modulatory effect of FABP may be due to the binding of long chain fatty acyl-CoA or fatty acid rather than a direct effect of FABPs on the enzyme

4 citations

Journal Article
TL;DR: The results indicate the importance of supply and/or synthesis of fatty acids when lung surfactant synthesis begins; thereby showing a correlation between the FABPs, lipid pattern and the activities of fatty acid synthesizing enzymes during prenatal lung development.
Abstract: Levels of fatty acid binding proteins (FABPs), lipids as well as activities of fatty acid synthesizing enzymes such as fatty acid synthase and ATP-citrate lyase increase with gestation showing maximum at term in human fetal lung However, the activity of ATP-citrate lyase showed the same trend up to 30 weeks of gestation before declining slightly at term These results indicate the importance of supply and/or synthesis of fatty acids when lung surfactant synthesis begins; thereby showing a correlation between the FABPs, lipid pattern and the activities of fatty acid synthesizing enzymes during prenatal lung development

4 citations


Cited by
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Journal ArticleDOI
TL;DR: Article de synthese sur les donnees recentes de caracteristiques structurales et physicochimiques de divers types of proteines de liaison aux acides gras, avec la signification physiologique de ces diversites.

366 citations

Journal ArticleDOI
TL;DR: Molecular and biochemical studies show that ABCA3 is targeted to vesicle membranes and is found in the limiting membrane of lamellar bodies, suggesting that this protein may play a key role in lipid organization during the formation of lameLLar bodies.

197 citations

Journal ArticleDOI
TL;DR: A considerable body of indirect evidence is provided supporting a broad role for the FABP in the intracellular transport and metabolism of long-chain fatty acids and the existence of structure- and tissue-specific specialization of function among different members of the F ABP gene family.
Abstract: Cytosolic fatty acid binding proteins (FABP) belong to a gene family of which eight members have been conclusively identified. These 14–15 kDa proteins are abundantly expressed in a highly tissue-specific manner. Although the functions of the cytosolic FABP are not clearly established, they appear to enhance the transfer of long-chain fatty acids between artificial and native lipid membranes, and also to have a stimulatory effect on a number of enzymes of fatty acid metabolism in vitro. These findings, as well as the tissue expression, ligand binding properties, ontogeny and regulation of these proteins provide a considerable body of indirect evidence supporting a broad role for the FABP in the intracellular transport and metabolism of long-chain fatty acids. The available data also support the existence of structure- and tissue-specific specialization of function among different members of the FABP gene family. Moreover, FABP may also have a possible role in the modulation of cell growth and proliferation, possibly by virtue of their affinity for ligands such as prostaglandins, leukotrienes and fatty acids, which are known to influence cell growth activity. FABP structurally unrelated to the cytosolic gene family have also been identified in the plasma membranes of several tissues (FABPpm). These proteins have not been fully characterized to date, but strong evidence suggests that they function in the transport of long-chain fatty acids across the plasma membrane.

167 citations

Journal ArticleDOI
TL;DR: The strengths and weaknesses of H-FABP as a clinically applicable marker of myocyte necrosis in the context of acute coronary syndromes are reviewed.
Abstract: Heart fatty-acid-binding protein (FABP) is a small cytosolic protein that is abundant in the heart and has low concentrations in the blood and in tissues outside the heart. It appears in the blood as early as 1.5 h after onset of symptoms of infarction, peaks around 6 h and returns to baseline values in 24 h. These features of H-FABP make it an excellent potential candidate for the detection of acute myocardial infarction (AMI). We review the strengths and weaknesses of H-FABP as a clinically applicable marker of myocyte necrosis in the context of acute coronary syndromes.

147 citations

Journal ArticleDOI
TL;DR: It is shown that C/EBPα plays a crucial role in the maturation of the respiratory epithelium in late gestation, being required for the production of surfactant lipids and proteins necessary for lung function.
Abstract: Epithelial cells lining the peripheral lung synthesize pulmonary surfactant that reduces surface tension at the air-liquid interface. Lack of surfactant lipids and proteins in the lungs causes respiratory distress syndrome, a common cause of morbidity and mortality in preterm infants. We show that C/EBPalpha plays a crucial role in the maturation of the respiratory epithelium in late gestation, being required for the production of surfactant lipids and proteins necessary for lung function. Deletion of the Cebpa gene in respiratory epithelial cells in fetal mice caused respiratory failure at birth. Structural and biochemical maturation of the lung was delayed. Normal synthesis of surfactant lipids and proteins, including SP-A, SP-B, SP-C, SP-D, ABCA3 (a lamellar body associated protein) and FAS (precursor of fatty acid synthesis) were dependent upon expression of the C/EBPalpha in respiratory epithelial cells. Deletion of the Cebpa gene caused increased expression of Tgfb2, a growth factor that inhibits lung epithelial cell proliferation and differentiation. Normal expression of C/EBPalpha required Titf1 and Foxa2, transcription factors that also play an important role in perinatal lung differentiation. C/EBPalpha participates in a transcriptional network that is required for the regulation of genes mediating perinatal lung maturation and surfactant homeostasis that is necessary for adaptation to air breathing at birth.

131 citations