| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1993: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1992: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
Forty years ago, crude wasp venom from Polistes jadwigae was found to elevate the fertilization membrane(FM)of sea urchin eggs, but effective components of the venom have not been elucidated yet. Mastoparan, a peptide in the wasp venom, was thought to be the first candidate for such an effective component, because it was known to be able to activate G protein, which is a major transducer of biosignals in cells.
1. The activity of various natural wasp peptides to elevate the FM of sea urchin eggs was examined. Mastoparan was foudnd to elevate the FM in part, but it cannot be the effective component of the venom, because other wasp peptides, such as melittin and chemotactic peptides, could act to the eggs more effectively.
2. While mastoparan itself hardly elevates the FM of sea urchin eggs, it was found to obtain the activity by modification of N^<alpha>-or N^<epsilon>-amino groups. Among the analogs, [Lys(Dns)^<11>]mastoparan was most effective, but truncated derivatives of the dansylated peptide that lacked a few N-terminal residuees did not show any activity.
3. From various indirect evidences, [Lys(Dns)^<11>]mastoparan was not thought to activate the G protein to elevate the FM of sea urchin eggs. The peptide must promote only the topical cortical reactions, but it was also found to induce the aggregation of chromosomes and the formation of actin bundle. This indicates that the dansylaled mastoparan acts to the cells not as a non-specifiic detergent but as a promoter of the cortical reactions and the initial segmentation.
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