Conformational Stability and Dynamics in Crystals Recapitulate Protein Behavior in Solution.

Autor:	Sala BM; Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy., Le Marchand T; Centre de Résonance Magnétique Nucléaire à Très Hauts Champs (FRE 2034 CNRS, UCBL, ENS Lyon), Université de Lyon, Villeurbanne, France., Pintacuda G; Centre de Résonance Magnétique Nucléaire à Très Hauts Champs (FRE 2034 CNRS, UCBL, ENS Lyon), Université de Lyon, Villeurbanne, France., Camilloni C; Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy. Electronic address: carlo.camilloni@unimi.it., Natalello A; Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy. Electronic address: antonino.natalello@unimib.it., Ricagno S; Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy. Electronic address: stefano.ricagno@unimi.it.
Jazyk:	angličtina
Zdroj:	Biophysical journal [Biophys J] 2020 Sep 01; Vol. 119 (5), pp. 978-988. Date of Electronic Publication: 2020 Jul 24.
DOI:	10.1016/j.bpj.2020.07.015
Abstrakt:	A growing body of evidences has established that in many cases proteins may preserve most of their function and flexibility in a crystalline environment, and several techniques are today capable to characterize molecular properties of proteins in tightly packed lattices. Intriguingly, in the case of amyloidogenic precursors, the presence of transiently populated states (hidden to conventional crystallographic studies) can be correlated to the pathological fate of the native fold; the low fold stability of the native state is a hallmark of aggregation propensity. It remains unclear, however, to which extent biophysical properties of proteins such as the presence of transient conformations or protein stability characterized in crystallo reflect the protein behavior that is more commonly studied in solution. Here, we address this question by investigating some biophysical properties of a prototypical amyloidogenic system, β2-microglobulin in solution and in microcrystalline state. By combining NMR chemical shifts with molecular dynamics simulations, we confirmed that conformational dynamics of β2-microglobulin native state in the crystal lattice is in keeping with what observed in solution. A comparative study of protein stability in solution and in crystallo is then carried out, monitoring the change in protein secondary structure at increasing temperature by Fourier transform infrared spectroscopy. The increased structural order of the crystalline state contributes to provide better resolved spectral components compared to those collected in solution and crucially, the crystalline samples display thermal stabilities in good agreement with the trend observed in solution. Overall, this work shows that protein stability and occurrence of pathological hidden states in crystals parallel their solution counterpart, confirming the interest of crystals as a platform for the biophysical characterization of processes such as unfolding and aggregation. (Copyright © 2020 Biophysical Society. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu