Molecular basis for lipid transfer particle, lipophorin

Research Project

Project/Area Number	17K15071
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Structural biochemistry
Research Institution	Hokkaido University
Principal Investigator	Kita Shunsuke 北海道大学, 薬学研究院, 特任助教 (10702003)
Project Period (FY)	2017-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000) Fiscal Year 2018: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000) Fiscal Year 2017: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Keywords	脂質輸送 / 電子顕微鏡 / 昆虫 / タンパク質 / 脂質 / リポタンパク質 / リポホリン / カイコ / 蛋白質 / 生体分子
Outline of Final Research Achievements	The lipid transportation of insects are carried out by protein complex, lipophorin. Lipophorin-mediated lipid transportation is an insect specific system and has a unique feature that lipohorin is recycled after lipid transportation. In order to reveal the lipid transportation mechanism of lipophorin, structure analysis of silkworm lipophorin was performed. Lipohorin proteins used in this study were purified from heamolymph of silkworm larvae and was observed by electron microscope. The observed lipohorin particles showed uniform-sized spherical shape. Further LTP proteins which work together with lipophorin were also prepared and observed by electron microscope. The result showed that LTP particles bended in a middle like shrimp.
Academic Significance and Societal Importance of the Research Achievements	本研究を通じて、昆虫の脂質輸送を担うリポホリンやLTPの立体構造情報を部分的ではあるが解明した。昆虫の脂質輸送機構はヒトを含む高等生物とは異なり、独自のシステムとなっており立体構造も特徴的であるため、これまで知られてきた脂質輸送システムの概念をアップデートしたと言える。今後は昆虫の脂質輸送機構を模倣して、幅広く膜タンパク質やリポタンパク質の研究に応用していきたい。