Structure and Dynamics of Ribonuclease A during Thermal Unfolding: The Failure of the Zimm Model

التفاصيل البيبلوغرافية
العنوان: Structure and Dynamics of Ribonuclease A during Thermal Unfolding: The Failure of the Zimm Model
المؤلفون: Aurel Radulescu, Dieter Richter, Peter Falus, Ralf Biehl, Jennifer Fischer
المصدر: The journal of physical chemistry / B 125(3), 780-788 (2021). doi:10.1021/acs.jpcb.0c09476
بيانات النشر: American Chemical Society (ACS), 2021.
سنة النشر: 2021
مصطلحات موضوعية: Protein Folding, Materials science, Friction, education, Activation energy, 010402 general chemistry, Space (mathematics), Intrinsically disordered proteins, 01 natural sciences, Ribonucleases, Chain (algebraic topology), 0103 physical sciences, Materials Chemistry, ddc:530, Physical and Theoretical Chemistry, Spectroscopy, Quantitative Biology::Biomolecules, 010304 chemical physics, Dynamics (mechanics), Ribonuclease, Pancreatic, 0104 chemical sciences, Surfaces, Coatings and Films, Intrinsically Disordered Proteins, Chemical physics, Relaxation (physics), Protein folding
الوصف: Disordered regions as found in intrinsically disordered proteins (IDP) or during protein folding define response time to stimuli and protein folding times. Neutron spin-echo spectroscopy is a powerful tool to directly access the collective motions of the unfolded chain to enlighten the physical origin of basic conformational relaxation. During the thermal unfolding of native ribonuclease A, we examine the structure and dynamics of the disordered state within a two-state transition model using polymer models, including internal friction, to describe the chain dynamics. The presence of four disulfide bonds alters the disordered configuration to a more compact configuration compared to a Gaussian chain that is defined by the additional links, as demonstrated by coarse-grained simulation. The dynamics of the disordered chain is described by Zimm dynamics with internal friction (ZIF) between neighboring amino acids. Relaxation times are dominated by mode-independent internal friction. Internal friction relaxation times show an Arrhenius-like behavior with an activation energy of 33 kJ/mol. The Zimm dynamics is dominated by internal friction and suggest that the characteristic motions correspond to overdamped elastic modes similar to the motions observed for folded proteins but within a pool of disordered configurations spanning the configurational space. For IDP, internal friction dominates while solvent friction and hydrodynamic interactions are smaller corrections.
تدمد: 1520-5207
1520-6106
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b34d3adda1075e004a85dad6fcbee1f7
https://doi.org/10.1021/acs.jpcb.0c09476
حقوق: OPEN
رقم الأكسشن: edsair.doi.dedup.....b34d3adda1075e004a85dad6fcbee1f7
قاعدة البيانات: OpenAIRE