Detection, Purification and Identification of An Endogenous Inhibitor of l-Dopa Decarboxylase Activity from Human Placenta
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- Vassiliou, AG., Fragoulis, E.G. & Vassilacopoulou, D. Neurochem Res (2009) 34: 1089. doi:10.1007/s11064-008-9879-2
An endogenous inhibitor of l-Dopa decarboxylase activity was identified and purified from human placenta. The endogenous inhibitor of l-Dopa decarboxylase (Ddc) was localized in the membrane fraction of placental tissue. Treatment of membranes with phosphatidylinositol-specific phospholipase C or proteinase K did not affect membrane-associated Ddc inhibitory activity, suggesting that a population of the inhibitor is embedded within membranes. Purification was achieved by extraction from a nondenaturing polyacrylamide gel. The purification scheme resulted in the isolation of a single 35 kDa band, bearing l-Dopa decarboxylase inhibitory activity. The purified inhibitor was identified as Annexin V. The elucidation of the biological importance of the presence of an l-Dopa decarboxylase activity inhibitor in normal human tissues could provide us with new information leading to the better understanding of the biological pathways that Ddc is involved in.