We have used optical tweezers and molecular dynamics simulations to investigate the unfolding and refolding process of a stable monomeric form of HIV-1-protease (PR). We have characterized the behavior under tension of the native state (N), and that of the ensemble of partially folded (PF) conformations the protein visits en route to N, which collectively act as a long-lived state controlling the slow kinetic phase of the folding process. Our results reveal a rich network of unfolding events, where the native state unfolds either in a two-state manner or by populating an intermediate state I, while the PF state unravels through a multitude of pathways, underscoring its structural heterogeneity. Refolding of mechanically denatured HIV-1-PR monomers is also a multiple-pathway process. Molecular dynamics simulations allowed us to gain insight into possible conformations the protein adopts along the unfolding pathways, and provide information regarding possible structural features of the PF state.

The complex folding behavior of HIV-1-protease monomer revealed by optical-tweezer single-molecule experiments and molecular dynamics simulations / M. Caldarini, P. Sonar, I. Valpapuram, D. Tavella, C. Volonté, V. Pandini, M.A. Vanoni, A. Aliverti, R.A. Broglia, G. Tiana, C. Cecconi. - In: BIOPHYSICAL CHEMISTRY. - ISSN 0301-4622. - 195(2014 Aug 14), pp. 32-42. [10.1016/j.bpc.2014.08.001]

The complex folding behavior of HIV-1-protease monomer revealed by optical-tweezer single-molecule experiments and molecular dynamics simulations

M. Caldarini
Primo
;
V. Pandini;M.A. Vanoni;A. Aliverti;G. Tiana
;
2014

Abstract

We have used optical tweezers and molecular dynamics simulations to investigate the unfolding and refolding process of a stable monomeric form of HIV-1-protease (PR). We have characterized the behavior under tension of the native state (N), and that of the ensemble of partially folded (PF) conformations the protein visits en route to N, which collectively act as a long-lived state controlling the slow kinetic phase of the folding process. Our results reveal a rich network of unfolding events, where the native state unfolds either in a two-state manner or by populating an intermediate state I, while the PF state unravels through a multitude of pathways, underscoring its structural heterogeneity. Refolding of mechanically denatured HIV-1-PR monomers is also a multiple-pathway process. Molecular dynamics simulations allowed us to gain insight into possible conformations the protein adopts along the unfolding pathways, and provide information regarding possible structural features of the PF state.
HIV-1-protease; Intermediate states; Molecular dynamics simulations; Protein folding; Single-molecule studies
Settore FIS/03 - Fisica della Materia
14-ago-2014
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/238995
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