title: A [Lys⁴⁹]phospholipase A₂ from Protobothrops flavoviridis venom induces caspase-independent apoptotic cell death accompanied by rapid plasma-membrane rupture in human leukemia cells.
abstract: Protobothrops flavoviridis venom contains plural phospholipase A(2) (PLA(2)) isozymes. A [Lys(49)]PLA(2) called BPII induced cell death in human leukemia cells. PLA2, an [Asp(49)]PLA(2) that has much stronger lipolytic activity than BPII, failed to induce cell death. BPII-treated cells showed morphological changes, DNA fragmentation, and nuclear condensation. This BPII-induced apoptotic cell death was neither inhibited by inhibitors of caspases 3 and 6 nor accompanied by activation of procaspase 3, indicating that BPII-induced cell death is caspase independent. Since inactive p-bromophenacylated BPII induced cell death, BPII-induced apoptotic cell death is independent of PLA(2) lipolytic activity. Rapid externalization of phosphatidylserine in BPII-treated cells was observed for fluorescein isothiocyanate (FITC)-labeled annexin V. In the cells treated with BPII, this spread over the cell membranes, implying that the cell toxicity of BPII is mediated via its cell-surface receptor.
authors: Department of Applied Life Science, Faculty of Bioscience and Biotechnology, Sojo University, Kumamoto, Japan.
authors: Tatsuo
authors: T
authors: Murakami
authors: Nobuyuki
authors: N
authors: Kamikado
authors: Ryo
authors: R
authors: Fujimoto
authors: Kazuhiko
authors: K
authors: Hamaguchi
authors: Hitomi
authors: H
authors: Nakamura
authors: Takahito
authors: T
authors: Chijiwa
authors: Motonori
authors: M
authors: Ohno
authors: Naoko
authors: N
authors: Oda-Ueda