Thromb Haemost 1992; 67(06): 702-707
DOI: 10.1055/s-0038-1648526
Original Articles
Schattauer GmbH Stuttgart

Characterization of Three Alboaggregins Purified from Trimeresurus albolabris Venom

Manling Peng
The Department of Biochemistry and the Thrombosis Research Center, Temple University, School of Medicine, Philadelphia, PA, USA
,
Weiqi Lu
The Department of Biochemistry and the Thrombosis Research Center, Temple University, School of Medicine, Philadelphia, PA, USA
,
Edward P Kirby
The Department of Biochemistry and the Thrombosis Research Center, Temple University, School of Medicine, Philadelphia, PA, USA
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Publikationsverlauf

Received 05. September 1991

Accepted after revision 20. Dezember 1991

Publikationsdatum:
24. Juli 2018 (online)

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Summary

Alboaggregins (AL-A, AL-B, AL-C) isolated from Trimeresurus albolabris snake venom represent a new family of proteins which bind to platelet glycoprotein lb (GPIb). These alboaggregins were purified to homogeneity with ion exchange HPLC (Mono-Q column) and hydrophobic HPLC (TSK Phenyl-5PW column). On SDS-polyacrylamide gel electrophoresis, apparent molecular weights of AL-A, AL-B and AL-C were 52 kDa, 26 kDa, and 121 kDa respectively, under nonreducing conditions. Upon reduction, each alboaggregin showed two types of chains with apparent molecular weights in the range of 15-20 kDa. All three alboaggregins agglutinated formalin-fixed platelets. Agglutination activities and binding of labeled alboaggregins to GPIb were specifically inhibited by the monoclonal antibody AK2 which is directed against the 45 kDa N-terminal region on GPIb, but not by monoclonal antibodies against other epitopes on GPIb. 125I-alboaggregin binding to platelets was not altered by the presence of thrombin. Alboaggregins did not bind to GPIIb/IIIa. Alboaggregins were competitive inhibitors for 125I-bovine vWF binding to platelets. Mutual competition studies between AL-A, AL-B and AL-C for the binding of labeled bovine vWF and AL-B to platelets demonstrated that AL-B and AL-C had a significantly higher affinity than AL-A.