A dimeric form of lipocortin-1 in human placenta.

Article Details


Pepinsky RB, Sinclair LK, Chow EP, O'Brine-Greco B

A dimeric form of lipocortin-1 in human placenta.

Biochem J. 1989 Oct 1;263(1):97-103.

PubMed ID
2532504 [ View in PubMed

We have characterized a 68 kDa lipocortin from human placenta that was identified as a covalently linked homodimer of lipocortin-1 by peptide mapping and sequence analysis. The site of cross-linking was localized within the 3 kDa N-terminal tail region, an exposed domain that contains the phosphorylation sites for protein tyrosine kinase and protein kinase C and is sensitive to proteolysis. Sequence analysis of the corresponding peptide revealed that glutamine-18 was modified, suggesting that the cross-link may be generated by a transglutaminase. By incubating lipocortin-1 with placental membranes and with labelled glycine ethyl ester we observed a Ca2+-dependent labelling of lipocortin-1 within the tail region, supporting this notion. Like lipocortin-1, the dimer inhibits phospholipase Ad2 activity, is a substrate for the epidermal-growth-factor (EGF) receptor/kinase, and display Ca2+-dependent binding to phosphatidylserine-containing vesicles. In preparations from human placenta the dimer is particularly abundant, accounting for approx. 20% of the lipocortin-1.

DrugBank Data that Cites this Article

NameUniProt ID
Annexin A1P04083Details