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Darvazi M, Ghorbani M, Ramazi S, Allahverdi A, Abdolmaleki P. A computational study of the R120G mutation in human αB-crystallin: implications for structural stability and functionality. J Biomol Struct Dyn 2024; 42:5788-5798. [PMID: 37354135 DOI: 10.1080/07391102.2023.2229434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/17/2023] [Indexed: 06/26/2023]
Abstract
The eye is a vital organ in the visual system, which is composed of transparent vascular tissue. αB-crystallin, a significant protein found in the lens, plays a crucial role in our understanding of lens diseases. Mutations in the αB-crystallin protein can cause lens diseases, such as cataracts and myopathy. However, the molecular mechanism underlying the R120G mutation is not fully understood. In this study, we utilized molecular dynamics simulations to illustrate, in atomic detail, how the R120G mutation leads to the aggregation of αB-crystallin and scattering of light in the lens. Our findings show that the R120G mutation alters the dynamic and structural properties of the αB-crystallin protein. Specifically, this mutation causes the angle of the hairpin at the C-terminal to increase from 80° to 150°, while reducing the distance between the hydrophobic patches around residues 10 and 44-55 from 1.5 nm to 1 nm. In addition, our results showed that the mutation could disrupt the IPI motif - β4/β8 interaction. The disruption of this interaction could affect the αB-crystallin oligomerization and the chaperone activity of αB-crystallin protein. The exposed hydrophobic area at the IPI motif - β4/β8 could become the primary site for interprotein interactions, which are responsible for large-scale aggregation. We have demonstrated that, in wild-type αB-crystallin protein, salt bridges R120 and D109, R107 and D80 are formed. However, in the case of the R120G mutation, the salt bridges R120 and R109 are disrupted, and a new salt bridge with a different pattern is formed. In our study, it has been found that all of the changes associated with the R120G mutation are located at the interface of chains A and B, which could impact the multimerization of the αB-crystallin. Previous research on the K92-E99 residue has shown that a salt bridge in the dimer I can reduce the chaperone activity of the protein. Furthermore, the salt bridges R120 and D109, as well as R107 and D80 in dimer II, induce changes in the hydrophobic envelope of β-sheets in the α-crystallin domain (ACD). These changes could have an impact on the multimerization of the αB-crystallin, leading to disruption of the oligomer structure and aggregation. Moreover, the changes in the αB-crystallin resulting from the R120G mutation can lead to faulty interactions with other proteins, which can cause the aggregation of αB-crystallin with other proteins, such as desmin. These findings may provide new insights into the development of treatments for lens diseases.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Mona Darvazi
- Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | | | - Shahin Ramazi
- Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Abdollah Allahverdi
- Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Parviz Abdolmaleki
- Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
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Somee LR, Barati A, Shahsavani MB, Hoshino M, Hong J, Kumar A, Moosavi-Movahedi AA, Amanlou M, Yousefi R. Understanding the structural and functional changes and biochemical pathomechanism of the cardiomyopathy-associated p.R123W mutation in human αB-crystallin. Biochim Biophys Acta Gen Subj 2024; 1868:130579. [PMID: 38307443 DOI: 10.1016/j.bbagen.2024.130579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/04/2024]
Abstract
αB-crystallin, a member of the small heat shock protein (sHSP) family, is expressed in diverse tissues, including the eyes, brain, muscles, and heart. This protein plays a crucial role in maintaining eye lens transparency and exhibits holdase chaperone and anti-apoptotic activities. Therefore, structural and functional changes caused by genetic mutations in this protein may contribute to the development of disorders like cataract and cardiomyopathy. Recently, the substitution of arginine 123 with tryptophan (p.R123W mutation) in human αB-crystallin has been reported to trigger cardiomyopathy. In this study, human αB-crystallin was expressed in Escherichia coli (E. coli), and the missense mutation p.R123W was created using site-directed mutagenesis. Following purification via anion exchange chromatography, the structural and functional properties of both proteins were investigated and compared using a wide range of spectroscopic and microscopic methods. The p.R123W mutation induced significant alterations in the secondary, tertiary, and quaternary structures of human αB-crystallin. This pathogenic mutation resulted in an increased β-sheet structure and formation of protein oligomers with larger sizes compared to the wild-type protein. The mutant protein also exhibited reduced chaperone activity and lower thermal stability. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) demonstrated that the p.R123W mutant protein is more prone to forming amyloid aggregates. The structural and functional changes observed in the p.R123W mutant protein, along with its increased propensity for aggregation, could impact its proper functional interaction with the target proteins in the cardiac muscle, such as calcineurin. Our results provide an explanation for the pathogenic intervention of p.R123W mutant protein in the occurrence of hypertrophic cardiomyopathy (HCM).
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Affiliation(s)
- Leila Rezaei Somee
- Protein Chemistry Laboratory (PCL), Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Anis Barati
- Protein Chemistry Laboratory (PCL), Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | | | - Masaru Hoshino
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Jun Hong
- School of Life Sciences, Henan University, Kaifen, People's Republic of China
| | - Ashutosh Kumar
- Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai, India
| | | | - Massoud Amanlou
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
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3
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Ghahramani M, Shahsavani MB, Khaleghinejad SH, Niazi A, Moosavi-Movahedi AA, Yousefi R. Efficient Expression in the Prokaryotic Host System, Purification and Structural Analyses of the Recombinant Human ACE2 Catalytic Subunit as a Hybrid Protein with the B Subunit of Cholera Toxin (CTB-ACE2). Protein J 2024; 43:24-38. [PMID: 38017315 DOI: 10.1007/s10930-023-10164-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2023] [Indexed: 11/30/2023]
Abstract
Angiotensin-converting enzyme 2 (ACE2) has a specific interaction with the coronavirus spike protein, enabling its entry into human cells. This membrane enzyme converts angiotensin II into angiotensin 1-7, which has an essential role in protecting the heart and improving lung function. Many therapeutic properties have been attributed to the human recombinant ACE2 (hrACE2), especially in combating complications related to diabetes mellitus and hypertension, as well as, preventing the coronavirus from entering the target tissues. In the current study, we designed an appropriate gene construct for the hybrid protein containing the ACE2 catalytic subunit and the B subunit of cholera toxin (CTB-ACE2). This structural feature will probably help the recombinant hybrid protein enter the mucosal tissues, including the lung tissue. Optimization of this hybrid protein expression was investigated in BL21 bacterial host cells. Also, the hybrid protein was identified with an appropriate antibody using the ELISA method. A large amount of the hybrid protein (molecular weight of ~ 100 kDa) was expressed as the inclusion body when the induction was performed in the presence of 0.25 mM IPTG and 1% sucrose for 10 h. Finally, the protein structural features were assessed using several biophysical methods. The fluorescence emission intensity and oligomeric size distribution of the CTB-ACE2 suggested a temperature-dependent alteration. The β-sheet and α-helix were also dominant in the hybrid protein structure, and this protein also displays acceptable chemical stability. In overall, according to our results, the efficient expression and successful purification of the CTB-ACE2 protein may pave the path for its therapeutic applications against diseases such as covid-19, diabetes mellitus and hypertension.
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Affiliation(s)
- Maryam Ghahramani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Mohammad Bagher Shahsavani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Seyed Hossein Khaleghinejad
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Ali Niazi
- Institute of Biotechnology, Shiraz University, Shiraz, Iran
| | | | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran.
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
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Hosseini Jafari M, Shahsavani MB, Hoshino M, Hong J, Saboury AA, Moosavi-Movahedi AA, Yousefi R. Unveiling the structural and functional consequences of the p.D109G pathogenic mutation in human αB-Crystallin responsible for restrictive cardiomyopathy and skeletal myopathy. Int J Biol Macromol 2024; 254:127933. [PMID: 37939764 DOI: 10.1016/j.ijbiomac.2023.127933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/02/2023] [Accepted: 11/05/2023] [Indexed: 11/10/2023]
Abstract
αB-Crystallin (αB-Cry) is expressed in many tissues, and mutations in this protein are linked to various diseases, including cataracts, Alzheimer's disease, Parkinson's disease, and several types of myopathies and cardiomyopathies. The p.D109G mutation, which substitutes a conserved aspartate residue involved in the interchain salt bridges, with glycine leads to the development of both restrictive cardiomyopathy (RCM) and skeletal myopathy. In this study, we generated this mutation in the α-Cry domain (ACD) which is crucial for forming the active chaperone dimeric state, using site-directed mutagenesis. After inducing expression in the bacterial host, we purified the mutant and wild-type recombinant proteins using anion exchange chromatography. Various spectroscopic evaluations revealed significant changes in the secondary, tertiary, and quaternary structures of human αB-Cry caused by this mutation. Furthermore, this pathogenic mutation led to the formation of protein oligomers with larger sizes than those of the wild-type protein counterpart. The mutant protein also exhibited increased chaperone activity and decreased chemical, thermal, and proteolytic stability. Atomic force microscopy (AFM), transmission electron microscopy (TEM), and fluorescence microscopy (FM) demonstrated that p.D109G mutant protein is more prone to forming amyloid aggregates. The misfolding associated with the p.D109G mutation may result in abnormal interactions of human αB-Cry with its natural partners (e.g., desmin), leading to the formation of protein aggregates. These aggregates can interfere with normal cellular processes and may contribute to muscle cell dysfunction and damage, resulting in the pathogenic involvement of the p.D109G mutant protein in restrictive cardiomyopathy and skeletal myopathy.
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Affiliation(s)
- Mehrnaz Hosseini Jafari
- Protein Chemistry Laboratory (PCL), Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | | | - Masaru Hoshino
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Jun Hong
- School of Life Sciences, Henan University, Kaifeng 475000, People's Republic of China
| | - Ali Akbar Saboury
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | | | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
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Khaleghinejad SH, Shahsavani MB, Ghahramani M, Yousefi R. Investigating the role of double mutations R12C/P20R, and R12C/R69C on structure, chaperone-like activity, and amyloidogenic properties of human αB-crystallin. Int J Biol Macromol 2023; 242:124590. [PMID: 37116845 DOI: 10.1016/j.ijbiomac.2023.124590] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 04/08/2023] [Accepted: 04/21/2023] [Indexed: 04/30/2023]
Abstract
α-crystallin is a structurally essential small heat shock protein (sHSP) with a chaperone-like activity which maintains transparency of the lenticular tissues during a period of time that is as long as human life. α-crystallin is a multimeric protein consisting of αA and αB subunits, with 57 % homology. The CRYAB gene on chromosome 11 encodes human αB-crystallin (αB-Cry), which contains 175 amino acid residues. In the current study, the cataractogenic mutations R12C, P20R, R69C, and double mutations R12C/P20R and R12C/P20R were embedded into the human CRYAB gene. Following successful expression in the prokaryotic system and purification, a number of spectroscopic techniques, gel electrophoresis, dynamic light scattering (DLS), and transmission electron microscopy (TEM) were applied to assess the role of these mutations on the structure, amyloidogenicity, and biological function of human αB-Cry. The created mutations caused significant changes in the structure, and oligomeric state of human αB-Cry. These mutations, particularly R12C, R12C/P20R, and R12C/R69C, dramatically enhanced the tendency of this protein for the amyloid fibril formation and reduced its chaperone-like activity. Since double mutations R12C/P20R and R12C/P20R were able to intensely change the protein's structure and chaperone function, it can be suggested that they may play a destructive role in a cumulative manner. Our findings indicated that the simultaneous presence of two pathogenic mutations may have a cumulative destructive impacts on the structure and function of human αB-Cry and this observation is likely related to the disease severity of the mutated proteins.
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Affiliation(s)
- Seyed Hossein Khaleghinejad
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Mohammad Bagher Shahsavani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Maryam Ghahramani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran; Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
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Ghahramani M, Shahsavani MB, Yousefi R. Increased chaperone activity of human αB-crystallin with incomplete oxidation as a new defense mechanism against oxidative stress. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140794. [PMID: 35643282 DOI: 10.1016/j.bbapap.2022.140794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 05/16/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Previous research has shown that production of the high levels of oxidants overwhelms the body's antioxidant defense system during diabetes mellitus. Under this circumstance, ocular lens proteins are one of the main molecular targets for oxidative damage. In the present study, the individual effect of partial and extensive oxidation on the structure and function of human αB-crystallin was investigated using electrophoresis and various spectroscopic methods. The results of our study suggested that widespread oxidation causes loss of the chaperone activity of this protein, while partial oxidation significantly enhances this activity. Our studies also suggested that partial and extensive oxidation induces the formation of different structures in this protein. In fact, the chaperone-active and chaperone-inactive states of this protein are respectively associated with a minor and extensive structural alteration. Moreover, the oligomeric size distribution shows an inverse relationship with the chaperone activity of this protein. Increasing the chaperone activity of this protein during partial oxidation may be a natural defense mechanism to overcome the damages caused by oxidative stress, especially in diabetes and other pathological diseases.
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Affiliation(s)
- Maryam Ghahramani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Mohammad Bagher Shahsavani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran; Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
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Ghanbarnezhad MM, Shahsavani MB, Mali PS, Upadhyay M, Kumar A, Albaghlani RM, Niazi A, Yousefi R. Developing a novel exenatide-based incretin mimic (αB-Ex): Expression, purification and structural-functional characterization. Biochim Biophys Acta Gen Subj 2022; 1866:130150. [DOI: 10.1016/j.bbagen.2022.130150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/30/2022] [Accepted: 04/07/2022] [Indexed: 10/18/2022]
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A novel method for the chaperone aided and efficient production of human proinsulin in the prokaryotic system. J Biotechnol 2022; 346:35-46. [DOI: 10.1016/j.jbiotec.2022.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 12/27/2021] [Accepted: 01/13/2022] [Indexed: 02/07/2023]
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9
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Nasiri P, Ghahramani M, Tavaf Z, Niazi A, Moosavi-Movahedi AA, Kurganov BI, Yousefi R. The biochemical association between R157H mutation in human αB-crystallin and development of cardiomyopathy: Structural and functional analyses of the mutant protein. Biochimie 2021; 190:36-49. [PMID: 34237397 DOI: 10.1016/j.biochi.2021.06.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/26/2021] [Accepted: 06/30/2021] [Indexed: 11/18/2022]
Abstract
In human αB-crystallin or HspB5, the substitution of arginine residue at position 157 with histidine has been reported to cause cardiomyopathy. In this study, the impact of R157H mutation on the structure, stability and functional properties of human αB-crystallin was investigated using a variety of spectroscopic techniques and microscopic analyses. Our spectroscopic analyses revealed that this mutation has a negligible impact on the secondary and tertiary structures of HspB5 but its quaternary structure underwent fundamental changes. Although the chemical stability of the mutant protein remained largely unchanged, the differential scanning calorimetry (DSC) measurement suggested that its thermal stability was reduced. As examined with transmission electron microscopy, αB-crystallin and its mutant indicated a similar tendency for the amyloid fibril formation under thermochemical stress. Dynamic light scattering (DLS) analysis suggested important changes in the quaternary (oligomeric) structures of the mutant protein as compared with the native protein counterpart. Also, the mutant protein indicated an improved chaperone-like activity under in vitro assessment. In a pH-dependent manner, the side chains of arginine and histidine have different capabilities for establishing hydrogen bonds and electrostatic interaction (salt bridge) and this variation may be sufficient to produce the larger changes that ultimately alter the interaction of this protein with other target proteins. Overall, the pathogenic contribution of this mutation in cardiomyopathy can be explained by its role in quaternary structure/stability alteration of the mutated protein.
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Affiliation(s)
- Parto Nasiri
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Maryam Ghahramani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Zohreh Tavaf
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Ali Niazi
- Institute of Biotechnology, Shiraz University, Shiraz, Iran
| | | | - Boris I Kurganov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, Bld. 2 Leninsky Ave., Moscow 119071, Russia
| | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran.
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Yu Y, Xu J, Qiao Y, Li J, Yao K. A new heterozygous mutation in the stop codon of CRYAB (p.X176Y) is liable for congenital posterior pole cataract in a Chinese family. Ophthalmic Genet 2020; 42:139-143. [PMID: 33272090 DOI: 10.1080/13816810.2020.1855665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Background: The present study aims to identify the underlying genetic defects in a Chinese family with autosomal dominant congenital cataracts (ADCC).Methods: Detailed family histories and clinical data were recorded. Targeted exome sequencing of 54 known cataract-associated genes combined with high-throughput next-generation sequencing was conducted followed by Sanger sequencing and bioinformatic analysis to identify the causative gene lesion for the family.Results: A four-generation Chinese family with posterior pole type cataract were enrolled. Enrichment of targeted genes revealed a new heterozygous p.X176Y mutation in the stop codon of αB-crystallin (CRYAB) gene, which resulted in the loss of the stop codon and prolongation of the mutant protein by 19 amino acid residues (p.X176Yfs19*). Sanger sequencing showed complete co-segregation with the disease. The elongated mutant protein was predicted to be pathogenic by forming new α-helix and random-coil in the secondary structure as well as producing an extended strand in the tertiary structure, potentially leading to increased hydrophobicity and reduced protein stability.Conclusions: Our report added a new mutation in the spectrum of congenital cataracts. The data suggested that X176 residue in the COOH-terminal is of crucial importance for the αB-crystallin protein function which was valuable for further study of the pathogenesis of congenital cataracts.Abbreviations: CRYAB: αB-crystallin; DNA: deoxyribonucleic acid; PCR: polymerase chain reaction; TES: targeted exome sequencing; ACD: αB-crystallin domain.
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Affiliation(s)
- Yinhui Yu
- Department of Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.,Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Jingjie Xu
- Department of Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.,Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Yue Qiao
- Department of Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.,Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Jinyu Li
- Department of Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.,Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China
| | - Ke Yao
- Department of Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.,Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou, Zhejiang Province, China
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Effect of Arginine on Chaperone-Like Activity of HspB6 and Monomeric 14-3-3ζ. Int J Mol Sci 2020; 21:ijms21062039. [PMID: 32188159 PMCID: PMC7139691 DOI: 10.3390/ijms21062039] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/10/2020] [Accepted: 03/12/2020] [Indexed: 12/26/2022] Open
Abstract
The effect of protein chaperones HspB6 and the monomeric form of the protein 14-3-3ζ (14-3-3ζm) on a test system based on thermal aggregation of UV-irradiated glycogen phosphorylase b (UV-Phb) at 37 °C and a constant ionic strength (0.15 M) was studied using dynamic light scattering. A significant increase in the anti-aggregation activity of HspB6 and 14-3-3ζm was demonstrated in the presence of 0.1 M arginine (Arg). To compare the effects of these chaperones on UV-Phb aggregation, the values of initial stoichiometry of the chaperone-target protein complex (S0) were used. The analysis of the S0 values shows that in the presence of Arg fewer chaperone subunits are needed to completely prevent aggregation of the UV-Phb subunit. The changes in the structures of HspB6 and 14-3-3ζm induced by binding of Arg were evaluated by the fluorescence spectroscopy and differential scanning calorimetry. It was suggested that Arg caused conformational changes in chaperone molecules, which led to a decrease in the thermal stability of protein chaperones and their destabilization.
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