Exhaustive Exploration of the Conformational Landscape of Small Cyclic Peptides Using a Robotics Approach

J Chem Inf Model. 2018 Nov 26;58(11):2355-2368. doi: 10.1021/acs.jcim.8b00375. Epub 2018 Oct 24.

Abstract

Small cyclic peptides represent a promising class of therapeutic molecules with unique chemical properties. However, the poor knowledge of their structural characteristics makes their computational design and structure prediction a real challenge. In order to better describe their conformational space, we developed a method, named EGSCyP, for the exhaustive exploration of the energy landscape of small head-to-tail cyclic peptides. The method can be summarized by (i) a global exploration of the conformational space based on a mechanistic representation of the peptide and the use of robotics-based algorithms to deal with the closure constraint and (ii) an all-atom refinement of the obtained conformations. EGSCyP can handle D-form residues and N-methylations. Two strategies for the side-chains placement were implemented and compared. To validate our approach, we applied it to a set of three variants of cyclic RGDFV pentapeptides, including the drug candidate Cilengitide. A comparative analysis was made with respect to replica exchange molecular dynamics simulations in implicit solvent. Its results show that the EGSCyP method provides a very complete characterization of the conformational space of small cyclic pentapeptides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Biomechanical Phenomena
  • Cluster Analysis
  • Molecular Dynamics Simulation*
  • Peptides, Cyclic / chemistry*
  • Pharmaceutical Preparations / chemistry
  • Protein Conformation
  • Protein Structure, Secondary
  • Snake Venoms / chemistry*

Substances

  • Peptides, Cyclic
  • Pharmaceutical Preparations
  • Snake Venoms
  • cyclo(arginyl-glycyl-aspartyl-phenylalanyl-valyl)
  • Cilengitide