Phospholipid biosynthetic enzymes in human brain

摘要: Growing evidence suggests an involvement of brain membrane phospholipid metabolism in a variety neurodegenerative and psychiatric conditions. This has prompted the use drugs (e.g., CDPcholine) aimed at elevating rate neural synthesis. However, no information is available regarding human enzymes synthesis which these affect. Thus, objective our study was to characterize involved, particular, whether differences existed relative affinity substrates for phosphatidylethanolamine (PE) compared those phosphatidylcholine (PC) The concentration choline rapidly frozen biopsies ranged from 32–186 nmol/g tissue, similar that determined previously ethanolamine. Since ethanolamine kinase possessed much lower (K m=460 μM) than did m=17 μM), activity vivo may be more dependent on substrate availability kinase. In addition, whereas inhibited by choline, lesser extent phosphocholine, unaffected presence ethanolamine, or phosphoethanolamine, only weakly phosphocholine. Phosphoethanolamine cytidylyl-transferase (PECT) phosphocholine cytidylyltransferase (PCCT) also displayed dissimilar characteristics, with PECT PCCT being located predominantly cytosolic particulate fractions, respectively. Both exhibited low CTP (Km approximately 1.2 mM), suggesting activities enzymes, implication, synthesis, are highly upon cellular CTP. conclusion, data indicate different regulatory properties PE PC brain, suggest (ethanolamine)