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Related papers: Modeling knotted proteins with tangles

200 papers

Simulations of knotting and unknotting in polymers or other filaments rely on random processes to facilitate topological changes. Here we introduce a method of \textit{topological steering} to determine the optimal pathway by which a…

Geometric Topology · Mathematics 2025-04-18 Agnese Barbensi , Alexander R. Klotz , Dimos Gkountaroulis

Knotted proteins, when forced through the pores, can get stuck if the knots in their backbone tighten under force. Alternatively, the knot can slide off the chain, making translocation possible. We construct a simple energy landscape model…

Statistical Mechanics · Physics 2023-11-08 Karol Capała , Piotr Szymczak

We consider multi-chain protein native structures and propose a criterion that determines whether two chains in the system are entangled or not. The criterion is based on the behavior observed by pulling at both temini of each chain…

Biomolecules · Quantitative Biology 2017-07-19 Yani Zhao , Mateusz Chwastyk , Marek Cieplak

Natural protein sequences that self-assemble to form globular structures are compact with high packing densities in the folded states. It is known that proteins unfold upon addition of denaturants, adopting random coil structures. The…

Biomolecules · Quantitative Biology 2016-12-02 Himadri S. Samanta , Pavel I. Zhuravlev , Michael Hinczewski , Naoto Hori , Shaon Chakrabarti , D. Thirumalai

Focusing on a small set of proteins that i) fold in a concerted, all-or-none fashion and ii) do not contain knots or slipknots, we show that the Gauss linking integral, the torsion and the number of sequence-distant contacts provide…

Quantitative Methods · Quantitative Biology 2019-10-01 E. Panagiotou , K. W. Plaxco

We develop a model characterizing all possible knots and links arising from recombination starting with a twist knot substrate, extending previous work of Buck and Flapan. We show that all knot or link products fall into three…

Geometric Topology · Mathematics 2015-05-19 Dorothy Buck , Karin Valencia

How proteins fold remains a central unsolved problem in biology. While the idea of a folding code embedded in the amino acid sequence was introduced more than 6 decades ago, this code remains undefined. While we now have powerful predictive…

Biomolecules · Quantitative Biology 2025-11-04 Carlos Bustamante , Christian Kaiser , Erik Lindahl , Robert Sosa , Giovanni Volpe

We study the folding process in the shallowly knotted protein MJ0366 within two variants of a structure-based model. We observe that the resulting topological pathways are much richer than identified in previous studies. In addition to the…

Biological Physics · Physics 2015-09-04 Mateusz Chwastyk , Marek Cieplak

Knotted molecules occur naturally and are designed by scientists to gain special biological and material properties. Understanding and utilizing knotting require efficient methods to recognize and generate knotted structures, which are…

Computational Physics · Physics 2025-01-23 Zhiyu Zhang , Yongjian Zhu , Liang Dai

Knotted proteins embed a physical (i.e., open) knot within their native structures. For decades, significant effort has been devoted to elucidating the functional role of knots in proteins, yet no consensus has been reached. Here, using…

Biomolecules · Quantitative Biology 2026-03-13 João NC Especial , Patrícia FN Faísca

Apart from the knots formed by the main-chain, the proteins can form numerous topological structures, when included the covalent and ion-mediated interactions. In this work, we define the protein non-trivial $\theta$-curves and identify 7…

Soft Condensed Matter · Physics 2019-08-19 Pawel Dabrowski-Tumanski , Dimos Goundaroulis , Andrzej Stasiak , Joanna I. Sulkowska

Stochastic simulations of coarse-grained protein models are used to investigate the propensity to form knots in early stages of protein folding. The study is carried out comparatively for two homologous carbamoyltransferases, a…

Biomolecules · Quantitative Biology 2015-06-04 T. Skrbic , C. Micheletti , P. Faccioli

Recent experiments demonstrated that knots in single DNA strands can be formed by hydrodynamic compression in a nanochannel. In this letter, we further elucidate the underlying molecular mechanisms by carrying out a compression experiment…

Soft Condensed Matter · Physics 2021-11-23 Jan Rothörl , Sarah Wettermann , Peter Virnau , Aniket Bhattacharya

As protein folding is a NP-complete problem, artificial intelligence tools like neural networks and genetic algorithms are used to attempt to predict the 3D shape of an amino acids sequence. Underlying these attempts, it is supposed that…

Biomolecules · Quantitative Biology 2015-11-03 Jacques M. Bahi , Nathalie M. -L. Cote , Christophe Guyeux

Proper folding of deeply knotted proteins has a very low success rate even in structure-based models which favor formation of the native contacts but have no topological bias. By employing a structure-based model, we demonstrate that…

Biological Physics · Physics 2015-09-04 Mateusz Chwastyk , Marek Cieplak

The folding pathway and rate coefficients of the folding of a knotted protein are calculated for a potential energy function with minimal energetic frustration. A kinetic transition network is constructed using the discrete path sampling…

Biomolecules · Quantitative Biology 2010-07-05 Michael C. Prentiss , David J. Wales , Peter G. Wolynes

The principles underlying protein folding remains one of Nature's puzzles with important practical consequences for Life. An approach that has gathered momentum since the late 1990's, looks at protein hetero-polymers and their folding…

Computational Engineering, Finance, and Science · Computer Science 2011-10-05 Susan Khor

Polymers can be modeled as open polygonal paths and their closure generates knots. Knotted proteins detection is currently achieved via high-throughput methods based on a common framework insensitive to the handedness of knots. Here we…

Biomolecules · Quantitative Biology 2011-04-19 Federico Comoglio , Maurizio Rinaldi

The folding of a protein towards its native state is a rather complicated process. However there are empirical evidences that the folding time correlates with the contact order, a simple measure of the spatial organisation of the native…

Soft Condensed Matter · Physics 2017-12-06 Marco Baiesi , Enzo Orlandini , Flavio Seno , Antonio Trovato

Knots in proteins have been proposed to resist proteasomal degradation. Ample evidence associates proteasomal degradation with neurodegeneration. One interesting possibility is that indeed knotted conformers stall this machinery leading to…

Biomolecules · Quantitative Biology 2016-10-17 Michał Wojciechowski , Àngel Gómez-Sicilia , Mariano Carrión-Vázquez , Marek Cieplak