SEMINAR

The nucleus factory on bubble for amyloid beta peptide

Abstract
It has been reported that formation of amyloid fibrils is drastically accelerated with ultrasonic irradiation. Its mechanism, however, still remains unclear. We, then, researched the aggregation acceleration mechanism, experimentally and theoretically. We developed homebuilt experimental system, which allows us to control the irradiation condition (i.e. acoustic pressure and frequency) of ultrasonic wave. We performed the ultrasonic irradiation experiments for AB-40 peptide with various acoustic pressures and frequencies. The results show that the reaction rate constant for nucleation strongly depends on the second-harmonics acoustic pressure, which increases by a factor of 1000 by increasing the pressure, and that there is an optimum frequency for nucleation acceleration at ~30 kHz. For explaining these observations, we propose a theoretical model focusing on cavitation-bubble dynamics and succeeded in consistently reproduce the pressure and frequency dependences of the aggregation reaction.

BIOGRAPHY

2014-present: Graduate School of Engineering Science, Osaka University

Research Fields and Interests:
Nucleation reaction of amyloid aggregates often takes long time, preventing us from understanding essential characteristics of formation of amyloid fibrils. We found that pressure-and-frequency optimized ultrasonic irradiation drastically accelerates the nucleation reaction of amyloid peptides. I study the catalytic effect of cavitation bubble generated by ultrasonic wave on the aggregation reaction of peptides for clarifying the mechanism of ultrasonically induced fibril formation.