Detection of Fibril Nucleation in Micrometer-Sized Protein Condensates and Suppression of Sup35NM Fibril Nucleation by Liquid-Liquid Phase Separation.

Autor: Fukuyama M; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Sendai, Miyagi 980-8577, Japan.; Organization for Advanced Studies, Tohoku University, 2-1-1 Katahira, Sendai, Miyagi 980-8577, Japan., Nishinami S; Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennoudai, Tsukuba, Ibaraki 305-8573, Japan., Maruyama Y; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Sendai, Miyagi 980-8577, Japan., Ozawa T; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Sendai, Miyagi 980-8577, Japan., Tomita S; Health and Medical Research Institute, The National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan., Ohhashi Y; Graduate School of Science, Kobe University, 1-1, Rokkoudaichou, Nada, Kobe, Hyogo 657-8501, Japan., Kasuya M; Faculty of Production Systems Engineering and Sciences, Komatsu University, Nu 1-3, Yonchoumemachi, Komatsu, Ishikawa 923-0971, Japan., Gen M; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Sendai, Miyagi 980-8577, Japan., Chatani E; Graduate School of Science, Kobe University, 1-1, Rokkoudaichou, Nada, Kobe, Hyogo 657-8501, Japan., Shiraki K; Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennoudai, Tsukuba, Ibaraki 305-8573, Japan., Hibara A; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Sendai, Miyagi 980-8577, Japan.; Riken, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan.
Jazyk: angličtina
Zdroj: Analytical chemistry [Anal Chem] 2023 Jul 04; Vol. 95 (26), pp. 9855-9862. Date of Electronic Publication: 2023 Jun 22.
DOI: 10.1021/acs.analchem.3c00766
Abstrakt: Elucidating the link between amyloid fibril formation and liquid-liquid phase separation (LLPS) is crucial in understanding the pathologies of various intractable human diseases. However, the effect of condensed protein droplets generated by LLPS on nucleation (the initial step of amyloid formation) remains unclear because of the lack of available quantitative analysis techniques. This study aimed to develop a measurement method for the amyloid droplet nucleation rate based on image analysis. We developed a method to fix micrometer-sized droplets in gel for long-term observation of protein droplets with known droplet volumes. By combining this method with image analysis, we determined the nucleation dynamics in droplets of a prion disease model protein, Sup35NM, at the single-event level. We found that the nucleation was unexpectedly suppressed by LLPS above the critical concentration ( C *) and enhanced below C *. We also revealed that the lag time in the Thioflavin T assay, a semi-quantitative parameter of amyloid nucleation rate, does not necessarily reflect nucleation tendencies in droplets. Our results suggest that LLPS can suppress amyloid nucleation, contrary to the conventional hypothesis that LLPS enhances it. We believe that the proposed quantitative analytical method will provide insights into the role of LLPS from a pathological perspective.
Databáze: MEDLINE
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