Molecular mechanism of fungal bio-surfactant protein hydrophobin involving in biological functions of filamentous fungi at interfaces

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H03787
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: Tohoku University
• Principal Investigator: Abe Keietsu 東北大学, 農学研究科, 教授 (50312624)
• Co-Investigator(Kenkyū-buntansha): 藪 浩 東北大学, 材料科学高等研究所, 准教授 (40396255)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 糸状菌 / 界面活性タンパク質 / 自己組織化

Outline of Final Research Achievements

Hydrophobins are secreted amphipathic proteins ubiquitous among filamentous fungi. Hydrophobin RolA produced by Aspergillus oryzae attaches to solid surfaces, recruits esterase CutL1, and promotes hydrolysis of polyesters. Using a quartz crystal microbalance (QCM), we analyzed the kinetic properties of RolA adsorption to the surfaces of QCM electrodes chemically modified. We observed the assembled RolA structures on the surfaces by atomic force microscopy (AFM). The RolA-surface interaction was affected by the zeta potential of RolA. Adsorption of RolA to surfaces depended on its hydrophobic interaction with the surfaces. The kinetics of RolA adsorption and the structures formed depended on the amount of RolA, surface properties, and the pH of the buffer. Using the Langmuir-Blodgett method, we also analyzed the process by which RolA forms a self-assembled structure at the air-water interface and observed the structures on the hydrophobic or hydrophilic SiO2 substrates via AFM.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

本研究では従来の微生物学的および生化学的手法に加え、新たに界面化学的手法を導入して、様々な化学構造を有する固体表面を作製してHydrophobin (HP)と固体表面との相互作用とその後のHP自己組織化構造形成過程を可視化・定量化(動力学的)した。また固体高分子分解酵素のHP自己組織化構造への吸着過程の可視化にも成功した。これら研究は、申請者らが独自に開拓した研究領域の知見に基づき発展させたものであり独創的である。本成果は、糸状菌の感染や高分子分解の分子機構の理解に貢献するのみならず、感染防除やバイオマス分解、HPの免疫ステルス素材としての利用を目指す生物模倣技術への発展も期待される。