Tracking local and global structural changes in a protein by cold ion spectroscopy.

Autor:	Zviagin A; Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland. oleg.boiarkin@epfl.ch., Kopysov V; Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland. oleg.boiarkin@epfl.ch., Nagornova NS; Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland. oleg.boiarkin@epfl.ch., Boyarkin OV; Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland. oleg.boiarkin@epfl.ch.
Jazyk:	angličtina
Zdroj:	Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2022 Apr 06; Vol. 24 (14), pp. 8158-8165. Date of Electronic Publication: 2022 Apr 06.
DOI:	10.1039/d2cp00217e
Abstrakt:	Characterization of native structures of proteins in the gas phase remains challenging due to the unpredictable conformational changes the molecules undergo during desolvation and ionization. We spectroscopically studied cryogenically cooled protonated protein ubiquitin and its microhydrated complexes prepared in the gas phase in a range of charge states under different ionization conditions. The UV spectra appear vibrationally resolved for the unfolded protein, but become redshifted and smooth for the native-like structures of ubiquitin. This spectroscopic change results from the H-bonding of the hydroxyl of Tyr to the amide group of Glu-51 in the compact structures; the minimum length of this bond was estimated to be ∼1.7 Å. IR spectroscopy reflects the global structural change by observing redshifts of free NH/OH-stretch vibrational transitions. Evaporative cooling of microhydrated complexes of ubiquitin keeps the protein chilly during ionization, enabling native-like conformers with up to eight protons to survive in the gas phase.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu