Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 111, Issue 36, Pages 13069-13074Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1401065111
Keywords
protein folding; NCS-1; off-pathway intermediate; conformational dynamics; optical trapping
Categories
Funding
- Carlsberg Foundation
- Lundbeck Foundation
- Fondazione Cassa di Risparmio di Modena
- European Union (EU) [44952]
- Italian Ministry of Education, University, and Research (MIUR) [17DPXLNBEK]
- Italian MIUR Basic Research Investment Fund (FIRB) [RBPR05JH2P]
- Abdus Salam International Centre for Theoretical Physics, of United Nations Educational, Scientific and Cultural Organization (UNESCO)
- International Atomic Energy Agency (IAEA)
- Programme for Training and Research in Italian Laboratories (TRIL)
Ask authors/readers for more resources
Neurodegenerative disorders are strongly linked to protein misfolding, and crucial to their explication is a detailed understanding of the underlying structural rearrangements and pathways that govern the formation of misfolded states. Here we use single-molecule optical tweezers to monitor misfolding reactions of the human neuronal calcium sensor-1, a multispecific EF-hand protein involved in neurotransmitter release and linked to severe neurological diseases. We directly observed two misfolding trajectories leading to distinct kinetically trapped misfolded conformations. Both trajectories originate from an on-pathway intermediate state and compete with native folding in a calcium-dependent manner. The relative probability of the different trajectories could be affected by modulating the relaxation rate of applied force, demonstrating an unprecedented real-time control over the free-energy landscape of a protein. Constant-force experiments in combination with hidden Markov analysis revealed the free-energy landscape of the misfolding transitions under both physiological and pathological calcium concentrations. Remarkably for a calcium sensor, we found that higher calcium concentrations increased the lifetimes of the misfolded conformations, slowing productive folding to the native state. We propose a rugged, multidimensional energy landscape for neuronal calcium sensor-1 and speculate on a direct link between protein misfolding and calcium dysregulation that could play a role in neurodegeneration.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available