Effect of Correlated Pair Mutations in Protein Misfolding

J Phys Chem B. 2019 Jun 20;123(24):5069-5078. doi: 10.1021/acs.jpcb.9b03533. Epub 2019 Jun 10.

Abstract

A Monte Carlo simulation based sequence design method is proposed to explore the effect of correlated pair mutations in proteins. In the designed sequences, the most correlated residue pairs are identified and mutated with all possible amino acid pairs except those already present. The cumulative correlated pair mutations generated an array of mutated sequences. Results show a significant increase in the probability of misfolding for correlated pair mutations as compared to that of the random pair mutations. The pair mutations of correlated residues that are in contact record a higher probability of misfolding as compared to the correlated residues that are not in contact. The probability of misfolding increases on pair mutation of nonlocally correlated residue pairs as compared to that of the locally correlated residue pairs. The choice of a compact or expanded conformation does not depend on the type of correlated pair mutations. Pair mutation of the most correlated residue pairs at the surface with hydrophobic amino acids results in higher misfolding probability as compared to that in the core. An exactly opposite behavior is observed on pair mutation with hydrophilic and charged amino acid pairs. The neutral amino acid pairs do not differentiate between core and surface sites. This study may be used for targeted mutation experiments to predict complex mutation patterns, reengineer the existing proteins, and design new proteins with reduced misfolding propensity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / chemistry
  • Amino Acids / genetics
  • Hydrophobic and Hydrophilic Interactions
  • Molecular Dynamics Simulation
  • Monte Carlo Method
  • Mutation*
  • Protein Conformation
  • Protein Folding
  • Proteins / chemistry*
  • Proteins / genetics*
  • Surface Properties

Substances

  • Amino Acids
  • Proteins