We have characterized a large-scale inactive-to-active conformational change in the activation-loop of the insulin receptor kinase domain at the atomistic level via untargeted temperature-accelerated molecular dynamics (TAMD) and free-energy calculations using the string method. TAMD simulations consistently show folding of the A-loop into a helical conformation followed by unfolding to an active conformation, causing the highly conserved DFG-motif (Asp 1150, Phe 1151, and Gly 1152) to switch from the inactive "D-out/F-in" to the nucleotide-binding-competent "D-in/F-out" conformation. The minimum free-energy path computed from the string method preserves these helical intermediates along the inactive-to-active path, and the thermodynamic free-energy differences are consistent with previous work on various other kinases. The mechanisms revealed by TAMD also suggest that the regulatory spine can be dynamically assembled/disassembled either by DFG-flip or by movement of the αC-helix. Together, these findings both broaden our understanding of kinase activation and point to intermediates as specific therapeutic targets. © 2012 Biophysical Society.

"dFG-Flip" in the insulin receptor kinase is facilitated by a helical intermediate state of the activation loop / Vashisth, H.; Maragliano, L.; Abrams, C. F.. - In: BIOPHYSICAL JOURNAL. - ISSN 0006-3495. - 102:8(2012), pp. 1979-1987. [10.1016/j.bpj.2012.03.031]

"dFG-Flip" in the insulin receptor kinase is facilitated by a helical intermediate state of the activation loop

Maragliano L.;
2012-01-01

Abstract

We have characterized a large-scale inactive-to-active conformational change in the activation-loop of the insulin receptor kinase domain at the atomistic level via untargeted temperature-accelerated molecular dynamics (TAMD) and free-energy calculations using the string method. TAMD simulations consistently show folding of the A-loop into a helical conformation followed by unfolding to an active conformation, causing the highly conserved DFG-motif (Asp 1150, Phe 1151, and Gly 1152) to switch from the inactive "D-out/F-in" to the nucleotide-binding-competent "D-in/F-out" conformation. The minimum free-energy path computed from the string method preserves these helical intermediates along the inactive-to-active path, and the thermodynamic free-energy differences are consistent with previous work on various other kinases. The mechanisms revealed by TAMD also suggest that the regulatory spine can be dynamically assembled/disassembled either by DFG-flip or by movement of the αC-helix. Together, these findings both broaden our understanding of kinase activation and point to intermediates as specific therapeutic targets. © 2012 Biophysical Society.
2012
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11566/278466
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