PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network Model

Understanding the effects of missense mutations on protein stability is a widely acknowledged significant biological problem. Genomic missense mutations may alter one or more amino acids, leading to increased or decreased stability of the encoded proteins. In this study, we describe a novel approach...

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Main Author: Sambit Kumar Mishra
Format: Article
Language:English
Published: MDPI AG 2022-09-01
Series:International Journal of Molecular Sciences
Subjects:
Online Access:https://www.mdpi.com/1422-0067/23/18/10711
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author Sambit Kumar Mishra
author_facet Sambit Kumar Mishra
author_sort Sambit Kumar Mishra
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description Understanding the effects of missense mutations on protein stability is a widely acknowledged significant biological problem. Genomic missense mutations may alter one or more amino acids, leading to increased or decreased stability of the encoded proteins. In this study, we describe a novel approach—Protein Stability Prediction with a Gaussian Network Model (PSP-GNM)—to measure the unfolding Gibbs free energy change (ΔΔG) and evaluate the effects of single amino acid substitutions on protein stability. Specifically, PSP-GNM employs a coarse-grained Gaussian Network Model (GNM) that has interactions between amino acids weighted by the Miyazawa–Jernigan statistical potential. We used PSP-GNM to simulate partial unfolding of the wildtype and mutant protein structures, and then used the difference in the energies and entropies of the unfolded wildtype and mutant proteins to calculate ΔΔG. The extent of the agreement between the ΔΔG calculated by PSP-GNM and the experimental ΔΔG was evaluated on three benchmark datasets: 350 forward mutations (S350 dataset), 669 forward and reverse mutations (S669 dataset) and 611 forward and reverse mutations (S611 dataset). We observed a Pearson correlation coefficient as high as 0.61, which is comparable to many of the existing state-of-the-art methods. The agreement with experimental ΔΔG further increased when we considered only those measurements made close to 25 °C and neutral pH, suggesting dependence on experimental conditions. We also assessed for the antisymmetry (ΔΔG<i><sub>reverse</sub></i> = −ΔΔG<i><sub>forward</sub></i>) between the forward and reverse mutations on the Ssym+ dataset, which has 352 forward and reverse mutations. While most available methods do not display significant antisymmetry, PSP-GNM demonstrated near-perfect antisymmetry, with a Pearson correlation of −0.97. PSP-GNM is written in Python and can be downloaded as a stand-alone code.
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spelling doaj.art-4ba0a8f0156d431ea971d3309a57ebfc2023-11-23T16:46:33ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672022-09-0123181071110.3390/ijms231810711PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network ModelSambit Kumar Mishra0Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Rockville, MD 20850, USAUnderstanding the effects of missense mutations on protein stability is a widely acknowledged significant biological problem. Genomic missense mutations may alter one or more amino acids, leading to increased or decreased stability of the encoded proteins. In this study, we describe a novel approach—Protein Stability Prediction with a Gaussian Network Model (PSP-GNM)—to measure the unfolding Gibbs free energy change (ΔΔG) and evaluate the effects of single amino acid substitutions on protein stability. Specifically, PSP-GNM employs a coarse-grained Gaussian Network Model (GNM) that has interactions between amino acids weighted by the Miyazawa–Jernigan statistical potential. We used PSP-GNM to simulate partial unfolding of the wildtype and mutant protein structures, and then used the difference in the energies and entropies of the unfolded wildtype and mutant proteins to calculate ΔΔG. The extent of the agreement between the ΔΔG calculated by PSP-GNM and the experimental ΔΔG was evaluated on three benchmark datasets: 350 forward mutations (S350 dataset), 669 forward and reverse mutations (S669 dataset) and 611 forward and reverse mutations (S611 dataset). We observed a Pearson correlation coefficient as high as 0.61, which is comparable to many of the existing state-of-the-art methods. The agreement with experimental ΔΔG further increased when we considered only those measurements made close to 25 °C and neutral pH, suggesting dependence on experimental conditions. We also assessed for the antisymmetry (ΔΔG<i><sub>reverse</sub></i> = −ΔΔG<i><sub>forward</sub></i>) between the forward and reverse mutations on the Ssym+ dataset, which has 352 forward and reverse mutations. While most available methods do not display significant antisymmetry, PSP-GNM demonstrated near-perfect antisymmetry, with a Pearson correlation of −0.97. PSP-GNM is written in Python and can be downloaded as a stand-alone code.https://www.mdpi.com/1422-0067/23/18/10711Gaussian network modelsmissense mutationsprotein stabilityGibbs free energy changeMiyazawa–Jernigan potential
spellingShingle Sambit Kumar Mishra
PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network Model
International Journal of Molecular Sciences
Gaussian network models
missense mutations
protein stability
Gibbs free energy change
Miyazawa–Jernigan potential
title PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network Model
title_full PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network Model
title_fullStr PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network Model
title_full_unstemmed PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network Model
title_short PSP-GNM: Predicting Protein Stability Changes upon Point Mutations with a Gaussian Network Model
title_sort psp gnm predicting protein stability changes upon point mutations with a gaussian network model
topic Gaussian network models
missense mutations
protein stability
Gibbs free energy change
Miyazawa–Jernigan potential
url https://www.mdpi.com/1422-0067/23/18/10711
work_keys_str_mv AT sambitkumarmishra pspgnmpredictingproteinstabilitychangesuponpointmutationswithagaussiannetworkmodel