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Toyooka T, Koda S. [Management of occupational health for adverse health effects of beryllium and its compounds in workplaces - Recent trends and issues in Japan]. SANGYŌ EISEIGAKU ZASSHI = JOURNAL OF OCCUPATIONAL HEALTH 2020; 63:31-42. [PMID: 32788509 DOI: 10.1539/sangyoeisei.2020-030-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Beryllium is primarily used in its metallic form, in alloys, or in beryllium oxide ceramics. Its physical and mechanical properties make it useful for many applications across a range of industries. Because beryllium is recognized as a sensitizing and carcinogenic agent, the management of occupational health for workers who may be occupationally exposed to beryllium has long been an important issue in the world. Under these circumstances, the U.S. Occupational Safety and Health Administration (OSHA) had published a rule in January 2017, to prevent the development of chronic beryllium disease and lung cancer. This rule strengthens the regulations governing the use of beryllium and its compounds. With the announcement of the OSHA rule in January 2017, the purpose of this study is to gain insight into the health problems and industrial hygiene associated with the use of beryllium and share the issues related to the management of occupational health for persons working with beryllium in Japan. METHODS We collected information regarding the beryllium industry, beryllium exposure, beryllium-induced health disorders, OSHA rule of January 2017, and regulations for beryllium use in Japan. After reviewing them, we discussed the issues concerning occupational health management of workers exposed to beryllium in Japan. RESULTS It has been reconfirmed that in recent years, the most serious health problem due to beryllium exposure is chronic beryllium disease caused by beryllium sensitization. Management of occupational health that emphasizes reduction of beryllium sensitization and early detection of beryllium-sensitized workers is important. CONCLUSIONS It was suggested that the following should be considered as the issues of management of occupational health of workers exposed to beryllium in Japan: (1) Collect epidemiologic data on health hazards from beryllium exposure in Japan. (2) Review the diagnostic items of special medical check-ups. (3) Review the definition of beryllium and its compounds in the Ordinance on Prevention of Hazards due to Specified Chemical Substances.
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Affiliation(s)
| | - Shigeki Koda
- National Institute of Occupational Safety and Health
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Koirala M, Alexov E. Ab-initio binding of barnase–barstar with DelPhiForce steered Molecular Dynamics (DFMD) approach. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2020. [DOI: 10.1142/s0219633620500169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Receptor–ligand interactions are involved in various biological processes, therefore understanding the binding mechanism and ability to predict the binding mode are essential for many biological investigations. While many computational methods exist to predict the 3D structure of the corresponding complex provided the knowledge of the monomers, here we use the newly developed DelPhiForce steered Molecular Dynamics (DFMD) approach to model the binding of barstar to barnase to demonstrate that first-principles methods are also capable of modeling the binding. Essential component of DFMD approach is enhancing the role of long-range electrostatic interactions to provide guiding force of the monomers toward their correct binding orientation and position. Thus, it is demonstrated that the DFMD can successfully dock barstar to barnase even if the initial positions and orientations of both are completely different from the correct ones. Thus, the electrostatics provides orientational guidance along with pulling force to deliver the ligand in close proximity to the receptor.
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Affiliation(s)
- Mahesh Koirala
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Emil Alexov
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
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Kalayan J, Henchman RH, Warwicker J. Model for Counterion Binding and Charge Reversal on Protein Surfaces. Mol Pharm 2020; 17:595-603. [PMID: 31887056 DOI: 10.1021/acs.molpharmaceut.9b01047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The structural stability and solubility of proteins in liquid therapeutic formulations is important, especially since new generations of therapeutics are designed for efficacy before consideration of stability. We introduce an electrostatic binding model to measure the net charge of proteins with bound ions in solution. The electrostatic potential on a protein surface is used to separately group together acidic and basic amino acids into patches, which are then iteratively bound with oppositely charged counterions. This model is aimed toward formulation chemists for initial screening of a range of conditions prior to lab-work. Computed results compare well with experimental zeta potential measurements from the literature covering a range of solution conditions. Importantly, the binding model reproduces the charge reversal phenomenon that is observed with polyvalent ion binding to proteins and its dependence on ion charge and concentration. Intriguingly, protein sequence can be used to give similarly good agreement with experiment as protein structure, interpreted as resulting from the close proximity of charged side chains on a protein surface. Further, application of the model to human proteins suggests that polyanion binding and overcharging, including charge reversal for cationic proteins, is a general feature. These results add to evidence that addition of polyanions to protein formulations could be a general mechanism for modulating solution stability.
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Affiliation(s)
- Jas Kalayan
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom, and School of Chemistry , The University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Richard H Henchman
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom, and School of Chemistry , The University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Jim Warwicker
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom, and School of Chemistry , The University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
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De S, Sabu G, Zacharias M. Molecular mechanism of Be2+-ion binding to HLA-DP2: tetrahedral coordination, conformational changes and multi-ion binding. Phys Chem Chem Phys 2020; 22:799-810. [DOI: 10.1039/c9cp05695e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Be small and positive: the smaller size and higher charge of the Be2+-ion results in strong binding between the M2 peptide and the β-chain of HLA-DP2, which induces conformational changes at the periphery suitable for TCR binding.
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Affiliation(s)
- Susmita De
- Department of Applied Chemistry
- Cochin University of Science and Technology
- Kochi 682 022
- India
- Inter University Centre for Nanomaterials and Devices (IUCND)
| | - Gopika Sabu
- Department of Applied Chemistry
- Cochin University of Science and Technology
- Kochi 682 022
- India
| | - Martin Zacharias
- Physics Department
- Technical University of Munich
- Garching 85747
- Germany
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Kaiser Y, Eklund A, Grunewald J. Moving target: shifting the focus to pulmonary sarcoidosis as an autoimmune spectrum disorder. Eur Respir J 2019; 54:13993003.021532018. [PMID: 31000677 DOI: 10.1183/13993003.021532018] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 04/01/2019] [Indexed: 12/27/2022]
Abstract
Despite more than a century of research, the causative agent(s) in sarcoidosis, a heterogeneous granulomatous disorder mainly affecting the lungs, remain(s) elusive. Following identification of genetic factors underlying different clinical phenotypes, increased understanding of CD4+ T-cell immunology, which is believed to be central to sarcoid pathogenesis, as well as the role of B-cells and other cells bridging innate and adaptive immunity, contributes to novel insights into the mechanistic pathways influencing disease resolution or chronicity. Hopefully, new perspectives and state-of-the-art technology will help to shed light on the still-elusive enigma of sarcoid aetiology. This perspective article highlights a number of recent advances in the search for antigenic targets in sarcoidosis, as well as the main arguments for sarcoidosis as a spectrum of autoimmune conditions, either as a result of an external (microbial) trigger and/or due to defective control mechanisms regulating the balance between T-cell activation and inhibition.
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Affiliation(s)
- Ylva Kaiser
- Respiratory Medicine Unit, Dept of Medicine, Solna and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Anders Eklund
- Respiratory Medicine Unit, Dept of Medicine, Solna and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Johan Grunewald
- Respiratory Medicine Unit, Dept of Medicine, Solna and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
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Drobyshev E, Kybarskaya L, Dagaev S, Solovyev N. New insight in beryllium toxicity excluding exposure to beryllium-containing dust: accumulation patterns, target organs, and elimination. Arch Toxicol 2019; 93:859-869. [DOI: 10.1007/s00204-019-02432-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/14/2019] [Indexed: 01/28/2023]
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Interaction of Nevirapine with the Peptide Binding Groove of HLA-DRB1*01:01 and Its Effect on the Conformation of HLA-Peptide Complex. Int J Mol Sci 2018; 19:ijms19061660. [PMID: 29867033 PMCID: PMC6032195 DOI: 10.3390/ijms19061660] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 01/11/2023] Open
Abstract
Human leukocyte antigen (HLA)-DRB1*01:01 has been shown to be involved in nevirapine-induced hepatic hypersensitivity reactions. In the present study, in silico docking simulations and molecular dynamics simulations were performed to predict the interaction mode of nevirapine with the peptide binding groove of HLA-DRB1*01:01 and its possible effect on the position and orientation of the ligand peptide derived from hemagglutinin (HA). In silico analyses suggested that nevirapine interacts with HLA-DRB1*01:01 around the P4 pocket within the peptide binding groove and the HA peptide stably binds on top of nevirapine at the groove. The analyses also showed that binding of nevirapine at the groove will significantly change the inter-helical distances of the groove. An in vitro competitive assay showed that nevirapine (1000 μM) increases the binding of the HA peptide to HLA-DRB1*01:01 in an allele-specific manner. These results indicate that nevirapine might interact directly with the P4 pocket and modifies its structure, which could change the orientation of loaded peptides and the conformation of HLA-DRB1*01:01; these changes could be distinctively recognized by T-cell receptors. Through this molecular mechanism, nevirapine might stimulate the immune system, resulting in hepatic hypersensitivity reactions.
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Research to Practice Implications of High-Risk Genotypes for Beryllium Sensitization and Disease. J Occup Environ Med 2018; 58:855-60. [PMID: 27414009 DOI: 10.1097/jom.0000000000000805] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Beryllium workers may better understand their genetic susceptibility to chronic beryllium disease (CBD) expressed as population-based prevalence, rather than odds ratios from case-control studies. METHODS We calculated CBD prevalences from allele-specific DNA sequences of 853 workers for Human Leukocyte Antigen (HLA)-DPB1 genotypes and groups characterized by number of E69-containing alleles and by calculated surface electronegativity of HLA-DPB1. RESULTS Of 18 groups of at least 10 workers with specific genotypes, CBD prevalence was highest, 72.7%, for the HLA-DPB102:01:02/DPB117:01 genotype. Population-based grouped genotypes with two E69 alleles wherein one allele had -9 surface charge had a beryllium sensitization (BeS) of 52.6% and a CBD prevalence of 42.1%. CONCLUSIONS The high CBD and BeS prevalences associated with -9-charged E69 alleles and two E69s suggest that workers may benefit from knowing their genetic susceptibility in deciding whether to avoid future beryllium exposure.
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Yordanov V, Dimitrov I, Doytchinova I. Proteochemometrics-Based Prediction of Peptide Binding to HLA-DP Proteins. J Chem Inf Model 2017; 58:297-304. [PMID: 28719212 DOI: 10.1021/acs.jcim.7b00026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human leukocyte antigens (HLA) class II proteins are involved in the antigen processing in the antigen presenting cells. They form complexes with antigen peptide fragments. The peptide-HLA protein complexes are presented on the cell surface where they are recognized by helper T cells (Th cells). HLA-DP is one of the three HLA class II loci. The HLA-DP proteins are associated with a significant number of autoimmune diseases, as well as with a susceptibility or resistance to a number of infectious agents. In the present study, we apply proteochemometrics-a method for bioactivity modeling of multiple ligands binding to multiple target proteins-to derive and validate a robust model for peptide binding prediction to the 7 most frequent HLA-DP proteins. The model is able to identify 86% of the binders in the top 10% of the best predicted nonamers generated from one protein.
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Affiliation(s)
- Ventsislav Yordanov
- Faculty of Pharmacy, Medical University of Sofia , 2 Dunav Street, Sofia 1000, Bulgaria
| | - Ivan Dimitrov
- Faculty of Pharmacy, Medical University of Sofia , 2 Dunav Street, Sofia 1000, Bulgaria
| | - Irini Doytchinova
- Faculty of Pharmacy, Medical University of Sofia , 2 Dunav Street, Sofia 1000, Bulgaria
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Petukh M, Dai L, Alexov E. SAAMBE: Webserver to Predict the Charge of Binding Free Energy Caused by Amino Acids Mutations. Int J Mol Sci 2016; 17:547. [PMID: 27077847 PMCID: PMC4849003 DOI: 10.3390/ijms17040547] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 12/01/2022] Open
Abstract
Predicting the effect of amino acid substitutions on protein–protein affinity (typically evaluated via the change of protein binding free energy) is important for both understanding the disease-causing mechanism of missense mutations and guiding protein engineering. In addition, researchers are also interested in understanding which energy components are mostly affected by the mutation and how the mutation affects the overall structure of the corresponding protein. Here we report a webserver, the Single Amino Acid Mutation based change in Binding free Energy (SAAMBE) webserver, which addresses the demand for tools for predicting the change of protein binding free energy. SAAMBE is an easy to use webserver, which only requires that a coordinate file be inputted and the user is provided with various, but easy to navigate, options. The user specifies the mutation position, wild type residue and type of mutation to be made. The server predicts the binding free energy change, the changes of the corresponding energy components and provides the energy minimized 3D structure of the wild type and mutant proteins for download. The SAAMBE protocol performance was tested by benchmarking the predictions against over 1300 experimentally determined changes of binding free energy and a Pearson correlation coefficient of 0.62 was obtained. How the predictions can be used for discriminating disease-causing from harmless mutations is discussed. The webserver can be accessed via http://compbio.clemson.edu/saambe_webserver/.
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Affiliation(s)
- Marharyta Petukh
- Computational Biophysics and Bioinformatics, Physics Department, Clemson University, Clemson, SC 29634, USA.
| | - Luogeng Dai
- Computational Biophysics and Bioinformatics, Physics Department, Clemson University, Clemson, SC 29634, USA.
- Department of Computer Sciences, Clemson University, Clemson, SC 29634, USA.
| | - Emil Alexov
- Computational Biophysics and Bioinformatics, Physics Department, Clemson University, Clemson, SC 29634, USA.
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Abstract
Sarcoidosis is a systemic inflammatory disorder characterised by tissue infiltration by mononuclear phagocytes and lymphocytes with associated non-caseating granuloma formation. Originally described as a disorder of the skin, sarcoidosis can involve any organ with wide-ranging clinical manifestations and disease course. Recent studies have provided new insights into the mechanisms involved in disease pathobiology, and we now know that sarcoidosis has a clear genetic basis largely involving human leukocyte antigen (HLA) genes. In contrast to Mendelian-monogenic disorders--which are generally due to specific and relatively rare mutations often leading to a single amino acid change in an encoded protein--sarcoidosis results from genetic variations relatively common in the general population and involving multiple genes, each contributing an effect of varying magnitude. However, an individual may have the necessary genetic profile and yet the disease will not develop unless an environmental or infectious factor is encountered. Genetics appears also to contribute to the huge variability in clinical phenotype and disease behaviour. Moreover, it has been established that sarcoidosis granulomatous inflammation is a highly polarized T helper 1 immune response that starts with an antigenic stimulus followed by T cell activation via a classic HLA class II-mediated pathway. A complex network of lymphocytes, macrophages, and cytokines is pivotal in the orchestration and evolution of the granulomatous process. Despite these advances, the aetiology of sarcoidosis remains elusive and its pathogenesis incompletely understood. As such, there is an urgent need for a better understanding of disease pathogenesis, which hopefully will translate into the development of truly effective therapies.
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12
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Petukh M, Zhang M, Alexov E. Statistical investigation of surface bound ions and further development of BION server to include pH and salt dependence. J Comput Chem 2015; 36:2381-93. [PMID: 26484964 DOI: 10.1002/jcc.24218] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/16/2015] [Accepted: 09/07/2015] [Indexed: 12/25/2022]
Abstract
Ions are engaged in multiple biological processes in cells. By binding to the macromolecules or being mobile in the solvent, they maintain the integrity of the structure of macromolecules; participate in their enzymatic activity; or screen electrostatic interactions. While experimental methods are not always able to assign the exact location of ions, computational methods are in demand. Although the majority of computational methods are successful in predicting the position of ions buried inside macromolecules, they are less effective in deciphering positions of surface bound ions. Here, we propose the new BION algorithm (http://compbio.clemson.edu/bion_server_ph/) that predicts the location of the surface bound ions. It is more efficient and accurate compared to the previous version since it uses more advanced clustering algorithm in combination with pairing rules. In addition, the BION webserver allows specifying the pH and the salt concentration in predicting ions positions.
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Affiliation(s)
- Marharyta Petukh
- Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634
| | - Min Zhang
- Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634
| | - Emil Alexov
- Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634
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Petukh M, Kucukkal TG, Alexov E. On human disease-causing amino acid variants: statistical study of sequence and structural patterns. Hum Mutat 2015; 36:524-534. [PMID: 25689729 DOI: 10.1002/humu.22770] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/09/2015] [Indexed: 12/28/2022]
Abstract
Statistical analysis was carried out on large set of naturally occurring human amino acid variations, and it was demonstrated that there is a preference for some amino acid substitutions to be associated with diseases. At an amino acid sequence level, it was shown that the disease-causing variants frequently involve drastic changes in amino acid physicochemical properties of proteins such as charge, hydrophobicity, and geometry. Structural analysis of variants involved in diseases and being frequently observed in human population showed similar trends: disease-causing variants tend to cause more changes in hydrogen bond network and salt bridges as compared with harmless amino acid mutations. Analysis of thermodynamics data reported in the literature, both experimental and computational, indicated that disease-causing variants tend to destabilize proteins and their interactions, which prompted us to investigate the effects of amino acid mutations on large databases of experimentally measured energy changes in unrelated proteins. Although the experimental datasets were linked neither to diseases nor exclusory to human proteins, the observed trends were the same: amino acid mutations tend to destabilize proteins and their interactions. Having in mind that structural and thermodynamics properties are interrelated, it is pointed out that any large change in any of them is anticipated to cause a disease.
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Affiliation(s)
- Marharyta Petukh
- Department of Physics, Clemson University, Clemson, SC 29642, USA
| | - Tugba G Kucukkal
- Department of Physics, Clemson University, Clemson, SC 29642, USA
| | - Emil Alexov
- Department of Physics, Clemson University, Clemson, SC 29642, USA
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