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1. Machine-learning algorithm for identifying and predicting amyotrophic lateral sclerosis causal mutations

Author

Serveh Kamrava, Ali Sahimi, Justin Ichida, and Muhammad Sahimi

Abstract

We propose a machine learning (ML) method to classify ALS–causative and non–ALS–causative variants based on 24 variables in five different datasets. The proposed ML method classifies the five datasets with very high accuracy. In particular, it predicts the ALS variants with 100 percent accuracy, while its accuracy for the non-ALS variants is up to 99.31 percent. The trained classifier also identifies the nine most influencial mutation assessors that help distinguishing the two classes from each other. They are FATHMM_score, PROVEAN_score, Vest3_score, CADD_phred, DANN_score, meta-SVM_score, phyloP7way_vertebrate, metaLR, and REVEL. Thus, they may be used in future studies in order to reduce the time and cost of collecting data and carrying out experimental tests, as well as in studies with more focus on the recognized assessors.

Published
2022
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2. Publisher Correction: Trans-ancestry genome-wide association meta-analysis of prostate cancer identifies new susceptibility loci and informs genetic risk prediction

Author

Brian D. Carter, Gert De Meerleer, Michael B. Cook, Paul A. Townsend, Kim De Ruyck, Edward J. Saunders, Christopher A. Haiman, Atushi Takahashi, Sonja I. Berndt, Florence Menegaux, Cezary Cybulski, Barbara Nemesure, Loic Le Marchand, Sune F. Nielsen, Demetrius Albanes, Robert J. Hamilton, Ninghan Feng, Stella Koutros, Stephen J. Chanock, Wei Zheng, Thomas A. Sellers, Rick A. Kittles, Craig C. Teerlink, Stephen N. Thibodeau, Marija Gamulin, Artitaya Lophatananon, Niclas Håkansson, Fredrik Wiklund, Roberta McKean-Cowdin, Yuan Chun Ding, Nora Pashayan, Timothy J. Key, Børge G. Nordestgaard, Shannon K. McDonnell, Jong Y. Park, Laura Fachal, Martin Andreas Røder, Johanna Schleutker, Edward Giovannucci, Anssi Auvinen, Hardev Pandha, Maria Elena Martinez, Mitchell J. Machiela, Gill Barnett, Melissa C. Southey, Graham G. Giles, Barry S. Rosenstein, Stephen Watya, Bernd Holleczek, Pascal Blanchet, Agnieszka Michael, William J. Blot, James L. Mohler, Jack A. Taylor, Sarah L. Kerns, Adam S. Kibel, Piet Ost, Ana Vega, Richard M. Martin, Jennifer J. Hu, Nicholas Mancuso, Yukihide Momozawa, Robert J. MacInnis, Sue A. Ingles, Maureen Sanderson, Kai Uwe Saum, Markus Aly, Robert Szulkin, Davor Lessel, Hermann Brenner, Yves Akoli Koudou, Jan Lubinski, Mina Torres, Anselm Hennis, Eli Marie Grindedal, Csilla Sipeky, Susan L. Neuhausen, Alison M. Dunning, Alicja Wolk, Adam B. Murphy, Brandi Weaver, Mariana C. Stern, Paula Paulo, Stephanie J. Weinstein, Xueying Mao, Tobias Nordström, Neil Fleshner, Tokhir Dadaev, Teuvo L.J. Tammela, Jay H. Fowke, Tomislav Kuliš, Steven Joniau, Yudong Wu, Rosalind A. Eeles, Shan Chao Zhao, Kenneth Muir, Mark N. Brook, Hidewaki Nakagawa, Freddie C. Hamdy, Karina Dalsgaard Sørensen, Linda Steele, Alisha Chou, Dominika Wokołorczyk, Peggy Wan, Martin Eklund, Laurent Brureau, Lisa A. Cannon-Albright, Lilit C. Moss, Daniel J. Schaid, Luc Multigner, Benjamin A. Rybicki, Xin Sheng, Constance Turman, Ron H.N. van Schaik, Radka Kaneva, Zsofia Kote-Jarai, Frank Claessens, Katarina Cuk, Kay-Tee Khaw, Chad D. Huff, Henrik Grönberg, Kathryn L. Penney, Geraldine Cancel-Tassin, Eric A. Klein, Masashi Fujita, Jennifer Cullen, Michael Borre, Jenny L Donovan, Dana C. Crawford, Antonio Gómez-Caamaño, David V. Conti, Manuel Luedeke, Maya Ghoussaini, Janet L. Stanford, Peter Kraft, Ian M. Thompson, Koichi Matsuda, Soo-Hwang Teo, Christopher J. Logothetis, Robin J. Leach, Monique J. Roobol, Manuel R. Teixeira, Jose Esteban Castelao, Sara S. Strom, Vanio Mitev, Stig E. Bojesen, David J. Hunter, Wayne D. Tilley, Jyotsna Batra, Gerald L. Andriole, Christine Neslund-Dudas, Sara Lindström, Guido Jenster, Catherine M. Tangen, William S. Bush, Maren Weischer, Chavdar Slavov, Thomas J. Schnoeller, Javier Llorca, Claire Aukim-Hastie, Nawaid Usmani, Lisa G. Horvath, Daniel W. Lin, Esther M. John, Burcu F. Darst, Milan S. Geybels, Phyllis J. Goodman, Lynne R. Wilkens, Ali Amin Al Olama, Lorelei A. Mucci, Peter Iversen, Christiane Maier, Victoria L. Stevens, Andreia Brandão, Graham Casey, Neil G. Burnet, Ann W. Hsing, Hongwei Zhang, Laura E. Beane Freeman, Susan M. Gapstur, Sara Benlloch, James E. Mensah, Marie-Élise Parent, Jianfeng Xu, Bettina F. Drake, Jeannette T. Bensen, Azad Hassan Abdul Razack, Edward D. Yeboah, David E. Neal, John D. Carpten, Ruth C. Travis, Thomas J. Hoffmann, Thomas Van den Broeck, Jeri Kim, Ali Sahimi, Gemma Castaño-Vinyals, Alexander Lubwama, Leire Moya, Elio Riboli, Douglas F. Easton, Suzanne K. Chambers, Yong-Jie Lu, Melinda C. Aldrich, Manuela Gago-Dominguez, John S. Witte, Matthew Parliament, Gail P. Risbridger, Samantha E.T. Larkin, Lisa F. Newcomb, Fredrick R. Schumacher, Shiv Srivastava, Jasmine Lim, Meir J. Stampfer, Harry Ostrer, Judith A. Clements, Thérèse Truong, Catharine M L West, Zan Sun, Olivier Cussenot, Gyorgy Petrovics, Lovise Maehle, Elizabeth T. H. Fontham, William B. Isaacs, Hui Yi Lin, Rohit Varma, Elaine A. Ostrander, Manolis Kogevinas, Robert N. Hoover, Sandeep Singhal, Antonio Finelli, and Stephen K. Van Den Eeden

Subjects
0303 health sciences, business.industry, Published Erratum, MEDLINE, Genome-wide association study, Computational biology, Biology, medicine.disease, 03 medical and health sciences, Prostate cancer, 0302 clinical medicine, Meta-analysis, Genetics, medicine, Susceptibility locus, 06 Biological Sciences, 11 Medical and Health Sciences, Personalized medicine, Genetic risk, business, 030217 neurology & neurosurgery, 030304 developmental biology, Developmental Biology
Abstract

In the version of this article originally published, the names of the equally contributing authors and jointly supervising authors were switched. The correct affiliations are: “These authors contributed equally: David V. Conti, Burcu F. Darst. These authors jointly supervised this work: David V. Conti, Rosalind A. Eeles, Zsofia Kote-Jarai, Christopher A. Haiman.” The error has been corrected in the HTML and PDF versions of the article.

Published
2021

3. Trans-ancestry genome-wide association meta-analysis of prostate cancer identifies new susceptibility loci and informs genetic risk prediction

Author

Paul A. Townsend, Edward J. Saunders, Hidewaki Nakagawa, Manuel R. Teixeira, Graham Casey, Demetrius Albanes, Christine Neslund-Dudas, Sara Lindström, William S. Bush, Maren Weischer, Lisa A. Cannon-Albright, Rick A. Kittles, Peggy Wan, Martin Eklund, Stephen N. Thibodeau, Burcu F. Darst, Fredrik Wiklund, Nicholas Mancuso, Jeri Kim, Jong Y. Park, Johanna Schleutker, Maureen Sanderson, Samantha E.T. Larkin, Radka Kaneva, Hongwei Zhang, Daniel J. Schaid, Luc Multigner, Marie-Élise Parent, Robert Szulkin, Fredrick R. Schumacher, Geraldine Cancel-Tassin, Jianfeng Xu, Gill Barnett, Melissa C. Southey, Yuan Chun Ding, Alexander Lubwama, Maria Elena Martinez, Manolis Kogevinas, Linda Steele, Laurent Brureau, Shiv Srivastava, Maya Ghoussaini, Alison M. Dunning, Adam B. Murphy, Kenneth Muir, Edward Giovannucci, Mitchell J. Machiela, James L. Mohler, Jack A. Taylor, Robert N. Hoover, Sandeep Singhal, Chavdar Slavov, Guido Jenster, Frank Claessens, Neil Fleshner, Sara Benlloch, Gert De Meerleer, Michael B. Cook, Zan Sun, Harry Ostrer, Pascal Blanchet, Lynne R. Wilkens, Ali Amin Al Olama, Sue A. Ingles, Markus Aly, Jay H. Fowke, Agnieszka Michael, Yves Akoli Koudou, Victoria L. Stevens, Kathryn L. Penney, Ana Vega, Xin Sheng, Ron H.N. van Schaik, Zsofia Kote-Jarai, Kim De Ruyck, Christopher A. Haiman, Atushi Takahashi, Florence Menegaux, Judith A. Clements, Stephen K. Van Den Eeden, Brian D. Carter, Wayne D. Tilley, Antonio Finelli, Jennifer J. Hu, Hermann Brenner, Thomas Van den Broeck, Shan Chao Zhao, Azad Hassan Abdul Razack, Edward D. Yeboah, Sonja I. Berndt, Barbara Nemesure, Mark N. Brook, David V. Conti, Katarina Cuk, Teuvo L.J. Tammela, Ali Sahimi, Stephen J. Chanock, Loic Le Marchand, Gemma Castaño-Vinyals, Sune F. Nielsen, Sara S. Strom, Ann W. Hsing, Roberta McKean-Cowdin, David J. Hunter, Ian M. Thompson, Børge G. Nordestgaard, Jyotsna Batra, Paula Paulo, Masashi Fujita, Jennifer Cullen, Susan M. Gapstur, Sarah L. Kerns, Lorelei A. Mucci, Neil G. Burnet, Xueying Mao, Hui Yi Lin, Rohit Varma, Marija Gamulin, Wei Zheng, Thomas A. Sellers, Adam S. Kibel, Robert J. Hamilton, Leire Moya, Ninghan Feng, Laura E. Beane Freeman, James E. Mensah, Catherine M. Tangen, Shannon K. McDonnell, Matthew Parliament, Davor Lessel, Gail P. Risbridger, Mina Torres, Janet L. Stanford, Bettina F. Drake, Soo-Hwang Teo, Robert J. MacInnis, Stig E. Bojesen, Jeannette T. Bensen, William J. Blot, Stella Koutros, Robin J. Leach, Graham G. Giles, Piet Ost, Artitaya Lophatananon, Laura Fachal, Tomislav Kuliš, Peter Kraft, Monique J. Roobol, Elaine A. Ostrander, Niclas Håkansson, Anselm Hennis, Yukihide Momozawa, Anssi Auvinen, Koichi Matsuda, Steven Joniau, Lisa G. Horvath, Javier Llorca, Claire Aukim-Hastie, Bernd Holleczek, Daniel W. Lin, Gerald L. Andriole, John D. Carpten, Eli Marie Grindedal, Rosalind A. Eeles, Elio Riboli, Constance Turman, Martin Andreas Røder, Yong-Jie Lu, Tobias Nordström, Kai Uwe Saum, Esther M. John, Melinda C. Aldrich, Peter Iversen, Henrik Grönberg, John S. Witte, Andreia Brandão, Eric A. Klein, Olivier Cussenot, Barry S. Rosenstein, Stephen Watya, Jan Lubinski, Douglas F. Easton, Dana C. Crawford, Gyorgy Petrovics, Thomas J. Schnoeller, Richard M. Martin, Stephanie J. Weinstein, Jose Esteban Castelao, Suzanne K. Chambers, Tokhir Dadaev, Karina Dalsgaard Sørensen, Antonio Gómez-Caamaño, Lisa F. Newcomb, Csilla Sipeky, Lovise Maehle, Brandi Weaver, Susan L. Neuhausen, Christiane Maier, Alicja Wolk, Vanio Mitev, Thérèse Truong, Manuel Luedeke, Jenny L Donovan, Mariana C. Stern, Catharine M L West, Manuela Gago-Dominguez, Elizabeth T. H. Fontham, William B. Isaacs, David E. Neal, Christopher J. Logothetis, Alisha Chou, Jasmine Lim, Benjamin A. Rybicki, Kay-Tee Khaw, Meir J. Stampfer, Chad D. Huff, Thomas J. Hoffmann, Michael Borre, Freddie C. Hamdy, Nawaid Usmani, Cezary Cybulski, Craig C. Teerlink, Milan S. Geybels, Nora Pashayan, Timothy J. Key, Phyllis J. Goodman, Hardev Pandha, Ruth C. Travis, Yudong Wu, Dominika Wokołorczyk, Lilit C. Moss, University of Southern California (USC), Keck School of Medicine [Los Angeles], CHU Tenon [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre de recherche en épidémiologie et santé des populations (CESP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Paul Brousse-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay, Institut de recherche en santé, environnement et travail (Irset), Université d'Angers (UA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), CHU Pointe-à-Pitre/Abymes [Guadeloupe], The institute of cancer research [London], U01CA194393, National Institutes of Health, NA, Achievement Rewards for College Scientists Foundation, Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique )-Institut National de la Santé et de la Recherche Médicale (INSERM)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université d'Angers (UA), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Université d'Angers (UA)-Université de Rennes (UR)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Urology, Clinical Chemistry, Darst, Burcu F [0000-0002-6205-4632], Chou, Alisha [0000-0001-7521-6373], Schumacher, Fredrick R [0000-0002-3073-7463], Dadaev, Tokhir [0000-0002-8268-0438], Brook, Mark N [0000-0002-8969-2378], Hoffmann, Thomas J [0000-0001-6893-4449], Takahashi, Atushi [0000-0001-7099-8767], Matsuda, Koichi [0000-0001-7292-2686], Fujita, Masashi [0000-0002-1457-6233], Muir, Kenneth [0000-0001-6429-988X], Stevens, Victoria L [0000-0003-0259-4407], Schleutker, Johanna [0000-0002-1863-0305], Sipeky, Csilla [0000-0002-8853-4722], Auvinen, Anssi [0000-0003-1125-4818], Giles, Graham G [0000-0003-4946-9099], Martin, Richard M [0000-0002-7992-7719], Nordestgaard, Børge G [0000-0002-1954-7220], Bojesen, Stig E [0000-0002-4061-4133], Røder, Martin Andreas [0000-0002-0019-5333], Batra, Jyotsna [0000-0003-4646-6247], Tilley, Wayne [0000-0003-1893-2626], Risbridger, Gail P [0000-0003-3089-4028], Gronberg, Henrik [0000-0002-1073-2753], Eklund, Martin [0000-0001-5032-5266], Nordström, Tobias [0000-0003-4915-7546], Pashayan, Nora [0000-0003-0843-2468], Dunning, Alison M [0000-0001-6651-7166], Travis, Ruth C [0000-0002-9571-0763], Riboli, Elio [0000-0001-6795-6080], Park, Jong Y [0000-0002-6384-6447], Weinstein, Stephanie J [0000-0002-3834-1535], Kraft, Peter [0000-0002-4472-8103], Ostrander, Elaine A [0000-0001-6075-9738], Wolk, Alicja [0000-0001-7387-6845], Håkansson, Niclas [0000-0001-7673-5554], Machiela, Mitchell J [0000-0001-6538-9705], Sørensen, Karina Dalsgaard [0000-0002-4902-5490], Zheng, Wei [0000-0003-1226-070X], Mensah, James E [0000-0003-4133-1722], Lu, Yong-Jie [0000-0001-6174-6621], West, Catharine ML [0000-0002-0839-3449], Cancel-Tassin, Géraldine [0000-0002-9583-6382], Truong, Thérèse [0000-0002-2943-6786], Vega, Ana [0000-0002-7416-5137], Gómez-Caamaño, Antonio [0000-0002-9773-4590], Fachal, Laura [0000-0002-7256-9752], Kerns, Sarah L [0000-0002-6503-0011], Ostrer, Harry [0000-0002-2209-5376], Teixeira, Manuel R [0000-0002-4896-5982], Brandão, Andreia [0000-0003-0938-1543], Cannon-Albright, Lisa [0000-0003-2602-3668], Multigner, Luc [0000-0003-3205-8568], Klein, Eric A [0000-0002-1783-0698], Murphy, Adam B [0000-0001-9977-3473], Michael, Agnieszka [0000-0002-7262-6227], Ost, Piet [0000-0002-2203-4848], Xu, Jianfeng [0000-0002-1343-8752], Teo, Soo-Hwang [0000-0002-0444-590X], Lessel, Davor [0000-0003-4496-244X], Kulis, Tomislav [0000-0002-0895-5691], Joniau, Steven [0000-0003-3195-9890], Bush, William S [0000-0002-9729-6519], Crawford, Dana C [0000-0002-6437-6248], Roobol, Monique J [0000-0001-6967-1708], Jenster, Guido [0000-0002-8658-2552], Van Den Eeden, Stephen K [0000-0002-5599-8387], Easton, Douglas F [0000-0003-2444-3247], Chanock, Stephen J [0000-0002-2324-3393], Wiklund, Fredrik [0000-0002-4623-0544], Eeles, Rosalind A [0000-0002-3698-6241], Haiman, Christopher A [0000-0002-0097-9971], and Apollo - University of Cambridge Repository

Subjects
Male, 8Q24, Genome-wide association study, Continental Population Groups/genetics, VARIANTS, Prostate cancer, 0302 clinical medicine, Risk Factors, Epidemiology, IMPUTATION, Odds Ratio, Prostatic Neoplasms/diagnosis, 0303 health sciences, education.field_of_study, Continental Population Groups, Manchester Cancer Research Centre, Middle Aged, Càncer--Aspectes genètics, 3. Good health, ODDS RATIOS, 06 Biological Sciences, 11 Medical and Health Sciences, medicine.medical_specialty, Population, Biology, prostate cancer, meta-analysis, SEQUENCE, Article, 03 medical and health sciences, Breast cancer, SDG 3 - Good Health and Well-being, Genetics, medicine, BREAST-CANCER, Humans, Genetic Predisposition to Disease, Neoplasm Invasiveness, education, 030304 developmental biology, Genetic association, [SDV.GEN]Life Sciences [q-bio]/Genetics, MUTATIONS, ResearchInstitutes_Networks_Beacons/mcrc, Racial Groups, Prostatic Neoplasms, Molecular Sequence Annotation, Odds ratio, medicine.disease, BRCA2, Pròstata--Càncer, Genetic Loci, 030217 neurology & neurosurgery, Imputation (genetics), Genètica, Demography, Developmental Biology, Genome-Wide Association Study
Abstract

International audience; Prostate cancer is a highly heritable disease with large disparities in incidence rates across ancestry populations. We conducted a multiancestry meta-analysis of prostate cancer genome-wide association studies (107,247 cases and 127,006 controls) and identified 86 new genetic risk variants independently associated with prostate cancer risk, bringing the total to 269 known risk variants. The top genetic risk score (GRS) decile was associated with odds ratios that ranged from 5.06 (95% confidence interval (CI), 4.84-5.29) for men of European ancestry to 3.74 (95% CI, 3.36-4.17) for men of African ancestry. Men of African ancestry were estimated to have a mean GRS that was 2.18-times higher (95% CI, 2.14-2.22), and men of East Asian ancestry 0.73-times lower (95% CI, 0.71-0.76), than men of European ancestry. These findings support the role of germline variation contributing to population differences in prostate cancer risk, with the GRS offering an approach for personalized risk prediction.

Published
2021
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4. Molecular Dynamics Study of Structure, Folding, and Aggregation of Poly-PR and Poly-GR Proteins

Author

Ali Sahimi, Size Zheng, Muhammad Sahimi, and Katherine S. Shing

Subjects
Arginine, Biophysics, Molecular Dynamics Simulation, medicine.disease_cause, 03 medical and health sciences, 0302 clinical medicine, C9orf72, medicine, Humans, Receptor, 030304 developmental biology, 0303 health sciences, Mutation, C9orf72 Protein, Chemistry, Amyotrophic Lateral Sclerosis, Proteins, Dipeptides, Articles, Folding (chemistry), Frontotemporal Dementia, Trinucleotide repeat expansion, 030217 neurology & neurosurgery, Ionotropic effect
Abstract

Poly-proline-arginine (poly-PR) and poly-glycine-arginine (poly-GR) proteins are believed to be the most toxic dipeptide repeat (DPR) proteins that are expressed by the hexanucleotide repeat expansion mutation in C9ORF72, which are associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) diseases. Their structural information and mechanisms of toxicity remain incomplete, however. Using molecular dynamics simulation and all-atom model of proteins, we study folding and aggregation of both poly-PR and poly-GR. The results indicate formation of double-helix structure during the aggregation of poly-PR into dimers, whereas no stable aggregate is formed during the aggregation of poly-GR; the latter only folds into α-helix and double-helix structures that are similar to those formed in the folding of poly-glycine-alanine (poly-GA) protein. Our findings are consistent with the experimental data indicating that poly-PR and poly-GR are less likely to aggregate because of the hydrophilic arginine residues within their structures. Such characteristics could, however, in some respect facilitate migration of the DPR proteins between and within cells and, at the same time, give proline residues the benefits of activating the receptors that regulate ionotropic effect in neurons, resulting in death or malfunction of neurons because of the abnormal increase or decrease of the ion transmission. This may explain the neurotoxicities of poly-PR and poly-GR associated with many neurodegenerative diseases. To our knowledge, this is the first molecular dynamics simulation of the phenomena involving poly-PR and poly-GR proteins.

Published
2020

5. Molecular dynamics study of structure, folding, and aggregation of poly-glycine-alanine (Poly-GA)

Author

Ali Sahimi, Katherine S. Shing, Size Zheng, and Muhammad Sahimi

Subjects
chemistry.chemical_classification, Alanine, Dipeptide, 010304 chemical physics, Molecular biophysics, General Physics and Astronomy, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Amino acid, Folding (chemistry), chemistry.chemical_compound, Molecular dynamics, chemistry, 0103 physical sciences, Glycine, Biophysics, Molecule, Physical and Theoretical Chemistry
Abstract

Poly-glycine-alanine (poly-GA) proteins are widely believed to be one of the main toxic dipeptide repeat molecules associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia diseases. Using discontinuous molecular dynamics simulation and an all-atom model of the proteins, we study folding, stability, and aggregation of poly-GA. The results demonstrate that poly-GA is an aggregation-prone protein that, after a long enough time, forms β-sheet-rich aggregates that match recent experiment data and that two unique helical structures are formed very frequently, namely, β-helix and double-helix. The details of the two structures are analyzed. The analysis indicates that such helical structures are stable and share the characteristics of both α-helices and β-sheets. Molecular simulations indicate that identical phenomena also occur in the aggregation of poly-glycine-arginine (poly-GR). Therefore, we hypothesize that proteins of type (GX)n in which X may be any non-glycine amino acid and n is the repeat length may share the same folding structures of β-helix and double-helix and that it is the glycine in the repeat that contributes the most to this characteristic. Molecular dynamics simulation with continuous interaction potentials and explicit water molecules as the solvent supports the hypothesis. To our knowledge, this is the first molecular dynamics simulation of the phenomena involving poly-GA and poly-GR proteins.

Published
2019

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