Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Complementary DNA clones encoding a protein highly homologous to the previously characterized long-chain acyl-CoA synthetase (LACS) in liver were isolated from rat brain cDNA libraries. This protein consists of 697 amino acids and has 64.7% identity with the rat liver LACS sequence. The brain protein and the liver LACS share essentially the same domain structure, having two regions similar to those of click beetle luciferase and a long discrete gap flanking the similar domains. A significant sequence similarity was found between the brain protein and malaria octapeptide-repeat antigen, suggesting a functional similarity. COS cells transfected with the cDNA for the brain protein expressed LACS activity with slightly different fatty acid specificity from that of the liver LACS. This new LACS is expressed predominantly in brain and, to a much lesser extent, in heart and adrenal. The 2.9- and 6.3-kb mRNAs coding for the brain enzyme are coregulated with the development of brain, suggesting the physiological importance of the enzyme in fatty acid metabolism in brain.
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PMID:Cloning and functional expression of a novel long-chain acyl-CoA synthetase expressed in brain. 156 43

In its blood stages the malaria parasite, Plasmodium, displays very high lipid metabolism. We present evidence for an abundant long-chain acyl-CoA synthetase (EC 6.2.1.3) activity in Plasmodium knowlesi-infected simian erythrocytes. The activity was found to be 20-fold higher in the schizont-infected (the last parasite stage) than in control erythrocytes. The cosubstrate requirements of the enzyme were similar to those previously reported for acyl-CoA synthetases from other sources. Among the separated reaction products of oleyl-CoA synthetase, only PPi and oleyl-CoA were inhibitory, with Ki over 350 microM. The fatty acid specificity of the parasite acyl-CoA synthetase activity was fairly marked and depended on the unsaturation state of the substrate. The tested fatty acids displayed similar Vmax, whereas their Km ranged from 11 (palmitate) to 59 microM (arachidonate). Finally, experiments involving heat inactivation and separation on hydroxyapatite excluded the presence of a specific arachidonyl-CoA synthetase identical to those present in other cells. On the other hand, fatty acid competition experiments evidenced the existence of at least two distinct enzymatic sites for fatty acid activation in P. knowlesi-infected simian erythrocytes: one is specific for saturated fatty acids and the other for polyunsaturated species, whereas oleate could be activated at both sites.
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PMID:Acyl-CoA synthetase activity in Plasmodium knowlesi-infected erythrocytes displays peculiar substrate specificities. 333 57