The development of a novel freeze-fracture replica labeling method for visualizing the hydrophobic part of the biological membrane

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19252
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 42:Veterinary medical science, animal science, and related fields
• Research Institution: Kagoshima University
• Principal Investigator: Fujita Akikazu 鹿児島大学, 農水産獣医学域獣医学系, 教授 (60282232)
• Co-Investigator(Kenkyū-buntansha): 正谷 達謄 岐阜大学, 応用生物科学部, 准教授 (70614072)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 脂肪酸 / ナノスケール / 急速凍結 / フリーズフラクチャー / 電子顕微鏡 / 生体膜

Outline of Final Research Achievements

We thought that hydrophobic portion of phospholipids may exposes in the biological membrane of the replica thin membrane by etching. However, the specific labelings of alkyne oleate or alkyne arachidonate could not be detected in these replicas of the biological membranes. On the other hand, the labeling of the alkyne arachidonate was detected in the replica membrane of the mitochondrial membrane which was made by the normal QF-FRL method. These results suggest that the alkyne of arachidonate indicating the terminal end of fatty acid of arachidonate is exposed on the hydrophilic surface of the mitochondrial membrane.

Free Research Field

脂質細胞生物学

Academic Significance and Societal Importance of the Research Achievements

本研究では、従来の方法とは逆に親水性頭部側から炭素を蒸着してレプリカを作成し、露出した膜脂質尾部の脂肪酸を標識する方法の開発を試みたが、現在までのところ予想したような結果は得られなかった。今後、この方法を開発するには課題は多く残るが、脂肪酸鎖の分布をナノスケールで明らかにすることができれば、これまでにない全く新しい知見を得られると確信している。