Purification and characterization of l-amino acid oxidase from king cobra ( Ophiophagus hannah) venom and its effects on human platelet aggregation
Z.-Y. Li, T.-F. Yu and E. C.-Y. Lian. Purification and characterization of l-amino acid oxidase from king cobra ( Ophiophagus hannah) venom and its effects on human platelet aggregation. Toxicon 32, 1349–1358, 1994.—Venoms of several snake species contain large amounts of l-amino acid oxidase but it...
Gespeichert in:
Veröffentlicht in: | Toxicon (Oxford) 1994-11, Vol.32 (11), p.1349-1358 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Z.-Y. Li,
T.-F. Yu and
E. C.-Y. Lian. Purification and characterization of
l-amino acid oxidase from king cobra (
Ophiophagus hannah) venom and its effects on human platelet aggregation.
Toxicon
32, 1349–1358, 1994.—Venoms of several snake species contain large amounts of
l-amino acid oxidase but its effects on human plasma coagulation and platelet aggregation have not been explored. We have purified
l-amino acid oxidase from king cobra venom through CM-Sephadex C-25, Sephadex G-100 and DEAE Sephadex A-50 chromatographies. The purified enzyme has a mol. wt of 135,000 as determined by gel filtration and 65,000 by SDS-PAGE under non-reducing and reducing conditions. Incubation of plasma with
l-amino acid oxidase at 200 μg/ml did not affect prothrombin time, activated partial thromboplastin time, or thrombin time. Upon addition of
l-amino acid oxidase, platelets in platelet-rich plasma were aggregated. The enzyme-induced aggregation was abolished by catalase. The aggregation was also inhibited by indomethacin, aspirin, ethylenediaminetetraacetate, sodium nitroprusside, prostaglandin E
1, mepacrine and verapamil, but not by heparin, hirudin, creatine phosphate/creatine phosphokinase or antimycin/2-deoxy-
d-glucose. These results suggest that
l-amino acid oxidase induces human platelet aggregation through the formation of H
2O
2, and subsequent thromboxane A
2 synthesis requiring Ca
2+ but independent of ADP release. The platelet aggregation caused by
l-amino acid oxidase is likely to contribute to toxicity inflicted by cobra venom. |
---|---|
ISSN: | 0041-0101 1879-3150 |
DOI: | 10.1016/0041-0101(94)90407-3 |