X-ray photon correlation spectroscopy of hydrated lysozyme at elevated pressures

Milla Åhlfeldt; Maddalena Bin; Anita Girelli; Iason Andronis; Aigerim Karina; Nimmi Das Anthuparambil; Fiona Berner; Tobias Eklund; Louisa E. Kraft; Aliaksandr Leonau; Fabian Westermeier; Michael Sprung; Christian Gutt; Katrin Amann-Winkel; Fivos Perakis

arXiv · 2512.02756

X-ray photon correlation spectroscopy of hydrated lysozyme at elevated pressures

Milla Åhlfeldt·Maddalena Bin·Anita Girelli·Iason Andronis·Aigerim Karina·Nimmi Das Anthuparambil·Fiona Berner·Tobias Eklund·Louisa E. Kraft·Aliaksandr Leonau·Fabian Westermeier·Michael Sprung·Christian Gutt·Katrin Amann-Winkel·Fivos Perakis

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Abstract

Pressure provides a powerful parameter to control the protein conformation state, which at sufficiently high values can lead to unfolding. Here, we investigate the effects of increasing pressure up to $0.4$ GPa on hydrated lysozyme proteins, by measuring the nanoscale stress relaxation induced and probed by X-rays. Structural and dynamical information at elevated pressures was obtained using X-ray photon correlation spectroscopy (XPCS) in combination with a diamond anvil cell (DAC). The dynamical analysis revealed a slowing down of the system up to $0.2$ GPa, followed by a re-acceleration at $0.4$ GPa. A similar non-monotonic behavior was observed both in the Porod and Kohlrausch-Williams-Watts (KWW) exponents, consistently indicating a crossover between $0.2$ and $0.4$ GPa. These findings suggest the presence of pressure-induced structural changes that impact protein collective stress-relaxation as the system transitions from a jammed state to an elastically driven regime. These results may be relevant for a deeper understanding of protein stability under compression as well as for practical high-pressure technologies, including food processing and pharmaceutical applications.

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Milla Åhlfeldt, Maddalena Bin, Anita Girelli, Iason Andronis, Aigerim Karina, Nimmi Das Anthuparambil, Fiona Berner, Tobias Eklund, Louisa E. Kraft, Aliaksandr Leonau, Fabian Westermeier, Michael Sprung, Christian Gutt, Katrin Amann-Winkel, Fivos Perakis. 2025-12-02. X-ray photon correlation spectroscopy of hydrated lysozyme at elevated pressures. https://arxiv.org/abs/2512.02756

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