Purification and Characterization of a Novel Membrane-Associated 48 kD Phospholipase A₂in Leaves of Vicia faba = 고등식물 Vicia faba의 잎으로부터 phospholipase A₂(PLA₂)의 분리정제 및 특성구명

다국어 초록 (Multilingual Abstract)

Several lines of evidence are accumulating that PLA, plays a crucial role in plant cellular responses through production of linoleic acid, which is the precursor of jasmonic acid. Here we report the purification and characterization of a 48 kD PLA_2 from the membrne fractions of leaves of Vicla faba. The plant PLA_2 was purified to near homogeneity by sequential column chromatographies from the membrane extracts solubilized with 2 mM sodium deoxycholate. The purified 48 kD protein migrated as a single band on a SDS-PAGE gel and was identified to be the PLA_2 enzyme by examining the band paralle with the activity. This 48 kD protein was identified as a plant form of PLA_2 enzyme through immunoprecipitation study using a monoclonal antibody against it. The purified plant PLA_2 preferred 2-linoleoyl-GPC to 2-palmitoyl-GPC and 2-arachidonoyl-GPC as substrate with a pH optimum at pH 7.0-8.0. The plant PLA_2 was activated by calmodulin and inhibited by pre-treatment of 5,8,11,14-eicosatetraynoic acid (ETYA) known as an inhibitor of mammalian PLA_2's. The enzyme was characterized as a calcium-independent PLA_2 different from mammalian PLA_2's. This membrane-associated and Ca^2+-independent PLA_2 is suggested to play an important role in the release of linoleic acid, the precursor of jasmonic acid, through a signal transduction pathway.

목차 (Table of Contents)

• 1.고등식물 Vicla faba의 잎으로부터 phospholipase A₂(PLA₂)의 분리정제 및 특성 구형
• 2.ABSTRACT
• 3.INTRODUCTION
• 4.RESULTS
• 5.DISCUSSION
• 6.ACKNOWLEDGEMENTS
• 7.LITERATURECITED