Galactose-specific lectin from Viscum album as a mediator of aggregation and priming of human platelets
Samal, A.B.; Gabius, H.J.; Timoshenko, A.V.
Anticancer Research 15(2): 361-367
1995
ISSN/ISBN: 0250-7005 PMID: 7763007 Document Number: 448992
Galactose-specific lectin from Viscum album (VAA) was found to induce aggregation of human platelets in a dose- and sugar-dependent manner. Small nonaggregating concentrations of VAA primed the response of platelets to known aggregants (ADP, arachidonic acid, thrombin, ristocetin, and A23187). VAA-induced platelet aggregation was completely reversible by addition of the sugar inhibitor lactose and the platelets from disrupted aggregates maintained the response to other aggregants. The lectin-induced aggregation of washed platelets was more resistant to metabolic inhibitors than thrombin- or arachidonic acid-dependent cell interaction. In contrast to the related galactose-specific lectin from Ricinus communis and the soy bean agglutinin, the lectin did not aggregate liposomes prepared from total platelet lipids, indicating different affinities of aggregation-mediating lectins to platelet glycolipids.