Study on the structure and formation mechanism of quantum beam crosslinked protein

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K12653
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 80040:Quantum beam science-related
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: Kimura Atsushi 国立研究開発法人量子科学技術研究開発機構, 高崎量子応用研究所 先端機能材料研究部, 上席研究員 (60465979)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: タンパク質 / 量子ビーム / 架橋 / メカニズム

Outline of Final Research Achievements

The aim of this work is to clarify the effects of quantum beam irradiation on the changing structures and physical properties (swelling ratio, elastic modulus, particle size) of proteins qualitatively and quantitatively. The contribution of OH radicals to the radiation crosslinking reaction of gelatin was 96%. It was clarified that the radiation cross-linking reaction of gelatin is predominantly caused by OH radicals. In addition, we quantitatively clarified for the first time that the aromatic amino acid residues contained in proteins, tyrosine, phenylalanine, and histidine, serve as crosslinking sites by detailed amino acid composition analysis of quantum beam crosslinked protein gels.

Free Research Field

量子ビーム科学

Academic Significance and Societal Importance of the Research Achievements

タンパク質の量子ビーム架橋メカニズムを定性・定量的に明らかにし、架橋タンパク質の物性（膨潤度、硬さ、粒径）変化の要因を初めて解明した。本研究で明らかにしたタンパク質の放射線架橋メカニズムに基づき、平均粒径5-20 nmを有する放射線架橋ゼラチンナノ粒子の作製に成功した。粒径を精密に制御したゼラチンナノゲルにGdを担持させ、MRI造影剤として腫瘍マウスへ投与した。直ちに腎臓に顕著なMRI信号上昇が観察され、投与2時間後には共に投与前の信号に近いレベルまで低下した。以上より、生体適合性の高いゼラチンを基材とした、脳内に入らず、体外排出の早い、より安全なMRI造影剤の作製に世界で初めて成功した。