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Martins M, Dos Santos AM, da Costa CHS, Canner SW, Chungyoun M, Gray JJ, Skaf MS, Ostermeier M, Goldbeck R. Thermostability Enhancement of GH 62 α-l-Arabinofuranosidase by Directed Evolution and Rational Design. J Agric Food Chem 2024; 72:4225-4236. [PMID: 38354215 DOI: 10.1021/acs.jafc.3c08019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
GH 62 arabinofuranosidases are known for their excellent specificity for arabinoxylan of agroindustrial residues and their synergism with endoxylanases and other hemicellulases. However, the low thermostability of some GH enzymes hampers potential industrial applications. Protein engineering research highly desires mutations that can enhance thermostability. Therefore, we employed directed evolution using one round of error-prone PCR and site-saturation mutagenesis for thermostability enhancement of GH 62 arabinofuranosidase from Aspergillus fumigatus. Single mutants with enhanced thermostability showed significant ΔΔG changes (<-2.5 kcal/mol) and improvements in perplexity scores from evolutionary scale modeling inverse folding. The best mutant, G205K, increased the melting temperature by 5 °C and the energy of denaturation by 41.3%. We discussed the functional mechanisms for improved stability. Analyzing the adjustments in α-helices, β-sheets, and loops resulting from point mutations, we have obtained significant knowledge regarding the potential impacts on protein stability, folding, and overall structural integrity.
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Affiliation(s)
- Manoela Martins
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, Maryland 21218, United States
- Department of Food Engineering, State University of Campinas, Monteiro Lobato, 80, Cidade Universitária, Campinas, São Paulo 13083-862, Brazil
| | - Alberto M Dos Santos
- Department of Chemistry, State University of Campinas, 336, R. Josué de Castro, 126-Cidade Universitária, Campinas, São Paulo 13083-861, Brazil
| | - Clauber H S da Costa
- Department of Chemistry, State University of Campinas, 336, R. Josué de Castro, 126-Cidade Universitária, Campinas, São Paulo 13083-861, Brazil
| | - Samuel W Canner
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, Maryland 21218, United States
| | - Michael Chungyoun
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, Maryland 21218, United States
| | - Jeffrey J Gray
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, Maryland 21218, United States
| | - Munir S Skaf
- Department of Chemistry, State University of Campinas, 336, R. Josué de Castro, 126-Cidade Universitária, Campinas, São Paulo 13083-861, Brazil
| | - Marc Ostermeier
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, Maryland 21218, United States
| | - Rosana Goldbeck
- Department of Food Engineering, State University of Campinas, Monteiro Lobato, 80, Cidade Universitária, Campinas, São Paulo 13083-862, Brazil
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Canner SW, Shanker S, Gray JJ. Structure-based neural network protein-carbohydrate interaction predictions at the residue level. Front Bioinform 2023; 3:1186531. [PMID: 37409346 PMCID: PMC10318439 DOI: 10.3389/fbinf.2023.1186531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/31/2023] [Indexed: 07/07/2023] Open
Abstract
Carbohydrates dynamically and transiently interact with proteins for cell-cell recognition, cellular differentiation, immune response, and many other cellular processes. Despite the molecular importance of these interactions, there are currently few reliable computational tools to predict potential carbohydrate-binding sites on any given protein. Here, we present two deep learning (DL) models named CArbohydrate-Protein interaction Site IdentiFier (CAPSIF) that predicts non-covalent carbohydrate-binding sites on proteins: (1) a 3D-UNet voxel-based neural network model (CAPSIF:V) and (2) an equivariant graph neural network model (CAPSIF:G). While both models outperform previous surrogate methods used for carbohydrate-binding site prediction, CAPSIF:V performs better than CAPSIF:G, achieving test Dice scores of 0.597 and 0.543 and test set Matthews correlation coefficients (MCCs) of 0.599 and 0.538, respectively. We further tested CAPSIF:V on AlphaFold2-predicted protein structures. CAPSIF:V performed equivalently on both experimentally determined structures and AlphaFold2-predicted structures. Finally, we demonstrate how CAPSIF models can be used in conjunction with local glycan-docking protocols, such as GlycanDock, to predict bound protein-carbohydrate structures.
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Affiliation(s)
- Samuel W. Canner
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States
| | - Sudhanshu Shanker
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Jeffrey J. Gray
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States
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Canner SW, Shanker S, Gray JJ. Structure-Based Neural Network Protein-Carbohydrate Interaction Predictions at the Residue Level. bioRxiv 2023:2023.03.14.531382. [PMID: 36993750 PMCID: PMC10054975 DOI: 10.1101/2023.03.14.531382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Carbohydrates dynamically and transiently interact with proteins for cell-cell recognition, cellular differentiation, immune response, and many other cellular processes. Despite the molecular importance of these interactions, there are currently few reliable computational tools to predict potential carbohydrate binding sites on any given protein. Here, we present two deep learning models named CArbohydrate-Protein interaction Site IdentiFier (CAPSIF) that predict carbohydrate binding sites on proteins: (1) a 3D-UNet voxel-based neural network model (CAPSIF:V) and (2) an equivariant graph neural network model (CAPSIF:G). While both models outperform previous surrogate methods used for carbohydrate binding site prediction, CAPSIF:V performs better than CAPSIF:G, achieving test Dice scores of 0.597 and 0.543 and test set Matthews correlation coefficients (MCCs) of 0.599 and 0.538, respectively. We further tested CAPSIF:V on AlphaFold2-predicted protein structures. CAPSIF:V performed equivalently on both experimentally determined structures and AlphaFold2 predicted structures. Finally, we demonstrate how CAPSIF models can be used in conjunction with local glycan-docking protocols, such as GlycanDock, to predict bound protein-carbohydrate structures.
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Affiliation(s)
- Samuel W. Canner
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States of America
| | - Sudhanshu Shanker
- Dept. of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - Jeffrey J. Gray
- Program in Molecular Biophysics, The Johns Hopkins University, Baltimore, MD, United States of America
- Dept. of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America
- Correspondence: Jeffrey J. Gray,
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Cavazos AT, Canner SW, Leng X, Petrache HI, Wassall SR. Cholesterol promotes similar chain packing in n-3 PUFA-containing membranes. Biophys J 2023; 122:82a. [PMID: 36785036 DOI: 10.1016/j.bpj.2022.11.651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Andres T Cavazos
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Samuel W Canner
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Xiaoling Leng
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Horia I Petrache
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Stephen R Wassall
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
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Canner SW, Feller SE, Wassall SR. Molecular Organization of a Raft-like Domain in a Polyunsaturated Phospholipid Bilayer: A Supervised Machine Learning Analysis of Molecular Dynamics Simulations. J Phys Chem B 2021; 125:13158-13167. [PMID: 34812629 DOI: 10.1021/acs.jpcb.1c06511] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Numerous health benefits are associated with omega-3 polyunsaturated fatty acids (n-3 PUFA) consumed in fish oils. An understanding of the mechanism remains elusive. The plasma membrane as a site of action is the focus in this study. With large-scale all-atom MD simulations run on a model membrane (1050 lipid molecules), we observed the evolution over time (6 μs) of a circular (raft-like) domain composed of N-palmitoylsphingomyelin (PSM) and cholesterol embedded into a surrounding (non-raft) patch composed of polyunsaturated 1-palmitoyl-2-docosahexaenoylphosphatylcholine (PDPC) (1:1:1 mol). A supervised machine learning algorithm was developed to characterize the migration of each lipid based on molecular conformation and the local environment. PDPC molecules were seen to infiltrate the ordered raft-like domain in a small amount, while a small concentration of PSM and cholesterol molecules was seen to migrate into the disordered non-raft region. Enclosing the raft-like domain, a narrow (∼2 nm in width) interfacial zone composed of PDPC, PSM, and cholesterol that buffers the substantial difference in order (ΔSCD ≈ 0.12) between raft-like and non-raft environments was seen to form. Our results suggest that n-3 PUFA regulate the architecture of lipid rafts enriched in sphingolipids and cholesterol with a minimal effect on order within their interior in membranes.
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Affiliation(s)
- Samuel W Canner
- Department of Physics, IUPUI, Indianapolis, Indiana 46202-3273, United States.,Department of Computer and Information Science, IUPUI, Indianapolis, Indiana 46202-5132, United States
| | - Scott E Feller
- Department of Chemistry, Wabash College, Crawfordsville, Indiana 47933, United States
| | - Stephen R Wassall
- Department of Physics, IUPUI, Indianapolis, Indiana 46202-3273, United States
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Canner SW, Phillips AQ, Feller SI, Wassall SR. Vitamin E's Affinity for Polyunsaturated Phospholipids Studied by All-Atom MD Simulations. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Canner SW, Zhu F, Feller SE, Wassall SR. A Role for Lipid-Lipid Interactions in Vitamin E's Function as a Membrane Antioxidant. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Wassall SR, Leng X, Canner SW, Pennington ER, Kinnun JJ, Cavazos AT, Dadoo S, Johnson D, Heberle FA, Katsaras J, Shaikh SR. Docosahexaenoic acid regulates the formation of lipid rafts: A unified view from experiment and simulation. Biochim Biophys Acta Biomembr 2018; 1860:1985-1993. [PMID: 29730243 DOI: 10.1016/j.bbamem.2018.04.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/27/2018] [Accepted: 04/28/2018] [Indexed: 01/02/2023]
Abstract
Docosahexaenoic acid (DHA, 22:6) is an n-3 polyunsaturated fatty acid (n-3 PUFA) that influences immunological, metabolic, and neurological responses through complex mechanisms. One structural mechanism by which DHA exerts its biological effects is through its ability to modify the physical organization of plasma membrane signaling assemblies known as sphingomyelin/cholesterol (SM/chol)-enriched lipid rafts. Here we studied how DHA acyl chains esterified in the sn-2 position of phosphatidylcholine (PC) regulate the formation of raft and non-raft domains in mixtures with SM and chol on differing size scales. Coarse grained molecular dynamics simulations showed that 1-palmitoyl-2-docosahexaenoylphosphatylcholine (PDPC) enhances segregation into domains more than the monounsaturated control, 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC). Solid state 2H NMR and neutron scattering experiments provided direct experimental evidence that substituting PDPC for POPC increases the size of raft-like domains on the nanoscale. Confocal imaging of giant unilamellar vesicles with a non-raft fluorescent probe revealed that POPC had no influence on phase separation in the presence of SM/chol whereas PDPC drove strong domain segregation. Finally, monolayer compression studies suggest that PDPC increases lipid-lipid immiscibility in the presence of SM/chol compared to POPC. Collectively, the data across model systems provide compelling support for the emerging model that DHA acyl chains of PC lipids tune the size of lipid rafts, which has potential implications for signaling networks that rely on the compartmentalization of proteins within and outside of rafts.
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Affiliation(s)
- Stephen R Wassall
- Department of Physics, Indiana University-Purdue University Indianapolis, United States.
| | - Xiaoling Leng
- Department of Physics, Indiana University-Purdue University Indianapolis, United States
| | - Samuel W Canner
- Department of Physics, Indiana University-Purdue University Indianapolis, United States; Department of Computer and Information Science, Indiana University-Purdue University Indianapolis, United States
| | - Edward Ross Pennington
- Department of Biochemistry & Molecular Biology, East Carolina University, United States; Department of Nutrition, Gillings School of Global Public Health and School of Medicine, The University of North Carolina at Chapel Hill, United States
| | - Jacob J Kinnun
- Department of Physics, Indiana University-Purdue University Indianapolis, United States
| | - Andres T Cavazos
- Department of Physics, Indiana University-Purdue University Indianapolis, United States
| | - Sahil Dadoo
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, The University of North Carolina at Chapel Hill, United States
| | - Dylan Johnson
- Department of Biochemistry & Molecular Biology, East Carolina University, United States
| | - Frederick A Heberle
- Joint Institute for Biological Sciences, University of Tennessee, Knoxville, TN, United States; Large Scale Structures Group, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - John Katsaras
- Large Scale Structures Group, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, United States; Shull Wollan Center-Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Saame Raza Shaikh
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, The University of North Carolina at Chapel Hill, United States.
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Leng X, Kinnun JJ, Cavazos AT, Canner SW, Shaikh SR, Feller SE, Wassall SR. All n-3 PUFA are not the same: MD simulations reveal differences in membrane organization for EPA, DHA and DPA. Biochim Biophys Acta Biomembr 2018; 1860:1125-1134. [PMID: 29305832 PMCID: PMC5963985 DOI: 10.1016/j.bbamem.2018.01.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 12/19/2017] [Accepted: 01/01/2018] [Indexed: 01/01/2023]
Abstract
Eicosapentaenoic (EPA, 20:5), docosahexaenoic (DHA, 22:6) and docosapentaenoic (DPA, 22:5) acids are omega-3 polyunsaturated fatty acids (n-3 PUFA) obtained from dietary consumption of fish oils that potentially alleviate the symptoms of a range of chronic diseases. We focus here on the plasma membrane as a site of action and investigate how they affect molecular organization when taken up into a phospholipid. All atom MD simulations were performed to compare 1-stearoyl-2-eicosapentaenoylphosphatylcholine (EPA-PC, 18:0-20:5PC), 1-stearoyl-2-docosahexaenoylphosphatylcholine (DHA-PC, 18:0-22:6PC), 1-stearoyl-2-docosapentaenoylphosphatylcholine (DPA-PC, 18:0-22:5PC) and, as a monounsaturated control, 1-stearoyl-2-oleoylphosphatidylcholine (OA-PC, 18:0-18:1PC) bilayers. They were run in the absence and presence of 20mol% cholesterol. Multiple double bonds confer high disorder on all three n-3 PUFA. The different number of double bonds and chain length for each n-3 PUFA moderates the reduction in membrane order exerted (compared to OA-PC, S¯CD=0.152). EPA-PC (S¯CD=0.131) is most disordered, while DPA-PC (S¯CD=0.140) is least disordered. DHA-PC (S¯CD=0.139) is, within uncertainty, the same as DPA-PC. Following the addition of cholesterol, order in EPA-PC (S¯CD=0.169), DHA-PC (S¯CD=0.178) and DPA-PC (S¯CD=0.182) is increased less than in OA-PC (S¯CD=0.214). The high disorder of n-3 PUFA is responsible, preventing the n-3 PUFA-containing phospholipids from packing as close to the rigid sterol as the monounsaturated control. Our findings establish that EPA, DHA and DPA are not equivalent in their interactions within membranes, which possibly contributes to differences in clinical efficacy.
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Affiliation(s)
- Xiaoling Leng
- Department of Physics, IUPUI, Indianapolis, IN 46202-3273, United States
| | - Jacob J Kinnun
- Department of Physics, IUPUI, Indianapolis, IN 46202-3273, United States
| | - Andres T Cavazos
- Department of Physics, IUPUI, Indianapolis, IN 46202-3273, United States
| | - Samuel W Canner
- Department of Physics, IUPUI, Indianapolis, IN 46202-3273, United States; Department of Computer Science and Information Science, IUPUI, Indianapolis, IN 46202-5132, United States
| | - Saame Raza Shaikh
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Scott E Feller
- Department of Chemistry, Wabash College, Crawfordsville, IN 47933, United States
| | - Stephen R Wassall
- Department of Physics, IUPUI, Indianapolis, IN 46202-3273, United States.
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Canner SW, Leng X, Zhu F, Wassall SR. Are Vitamin E and PUFA Driven Together by Choleterol? Computer Simulation Studies. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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