کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7560765 | 1491445 | 2017 | 19 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The unfolding mechanism of monomeric mutant SOD1 by simulated force spectroscopy
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
Mechanical unfolding of mutated apo, disulfide-reduced, monomeric superoxide dismutase 1 protein (SOD1) has been simulated via force spectroscopy techniques, using both an all-atom (AA), explicit solvent model and a coarse-grained heavy-atom GÅ (HA-GÅ) model. The HA-GÅ model was implemented at two different pulling speeds for comparison. The most-common sequence of unfolding in the AA model agrees well with the most-common unfolding sequence of the HA-GÅ model, when the same normalized pulling rate was used. Clustering of partially-native structures as the protein unfolds shows that the AA and HA-GÅ models both exhibit a dominant pathway for early unfolding, which eventually bifurcates repeatedly to multiple branches after the protein is about half-unfolded. The force-extension curve exhibits multiple force drops, which are concomitant with jumps in the local interaction potential energy between specific β-strands in the protein. These sudden jumps in the potential energy coincide with the dissociation of specific pairs of β-strands, and thus intermediate unfolding events. The most common sequence of β-strand dissociation in the unfolding pathway of the AA model is β-strands 5, 4, 8, 7, 1, 2, then finally β-strands 3 and 6. The observation that β-strand 5 is among the first to unfold here, but the last to unfold in simulations of loop-truncated SOD1, could imply the existence of an evolutionary compensation mechanism, which would stabilize β-strands flanking long loops against their entropic penalty by strengthening intramolecular interactions. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1865, Issue 11, Part B, November 2017, Pages 1631-1642
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1865, Issue 11, Part B, November 2017, Pages 1631-1642
نویسندگان
Mona Habibi, Jörg Rottler, Steven S. Plotkin,