Detection, purification and identification of an endogenous inhibitor of L-Dopa decarboxylase activity from human placenta.
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.
Vassiliou
Alice-Georgia
AG
Department of Biochemistry and Molecular Biology, University of Athens, Athens, Greece.
Fragoulis
Emmanuel G
EG
Vassilacopoulou
Dido
D
D000818:Animals; D017304:Annexin A5 / Q000302:isolation & purification* / Q000378:metabolism; D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D033622:Ceratitis capitata; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D008565:Membrane Proteins / Q000302:isolation & purification* / Q000378:metabolism; D008566:Membranes / Q000378:metabolism; D051379:Mice; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000302:isolation & purification* / Q000378:metabolism
D017304:Annexin A5; D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D011257:Pregnancy Proteins