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Zhou HH, Tang YL, Xu TH, Cheng B. C-reactive protein: structure, function, regulation, and role in clinical diseases. Front Immunol 2024; 15:1425168. [PMID: 38947332 PMCID: PMC11211361 DOI: 10.3389/fimmu.2024.1425168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 06/03/2024] [Indexed: 07/02/2024] Open
Abstract
C-reactive protein (CRP) is a plasma protein that is evolutionarily conserved, found in both vertebrates and many invertebrates. It is a member of the pentraxin superfamily, characterized by its pentameric structure and calcium-dependent binding to ligands like phosphocholine (PC). In humans and various other species, the plasma concentration of this protein is markedly elevated during inflammatory conditions, establishing it as a prototypical acute phase protein that plays a role in innate immune responses. This feature can also be used clinically to evaluate the severity of inflammation in the organism. Human CRP (huCRP) can exhibit contrasting biological functions due to conformational transitions, while CRP in various species retains conserved protective functions in vivo. The focus of this review will be on the structural traits of CRP, the regulation of its expression, activate complement, and its function in related diseases in vivo.
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Affiliation(s)
- Hai-Hong Zhou
- Centre for Translational Medicine, Gansu Provincial Academic Institute for Medical Research, Lanzhou, China
- Centre for Translational Medicine, Gansu Provincial Cancer Hospital, Lanzhou, China
- Centre for Translational Medicine, Sun Yat-sen University Cancer Center Gansu Hospital, Lanzhou, China
| | - Yu-Long Tang
- Ministry of Education (MOE), Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Tian-Hao Xu
- Ministry of Education (MOE), Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Bin Cheng
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Research Unit of Peptide Science, Chinese Academy of Medical Sciences, Lanzhou University, Lanzhou, China
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2
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Monomeric C-Reactive Protein in Atherosclerotic Cardiovascular Disease: Advances and Perspectives. Int J Mol Sci 2023; 24:ijms24032079. [PMID: 36768404 PMCID: PMC9917083 DOI: 10.3390/ijms24032079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/16/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
This review aimed to trace the inflammatory pathway from the NLRP3 inflammasome to monomeric C-reactive protein (mCRP) in atherosclerotic cardiovascular disease. CRP is the final product of the interleukin (IL)-1β/IL-6/CRP axis. Its monomeric form can be produced at sites of local inflammation through the dissociation of pentameric CRP and, to some extent, local synthesis. mCRP has a distinct proinflammatory profile. In vitro and animal-model studies have suggested a role for mCRP in: platelet activation, adhesion, and aggregation; endothelial activation; leukocyte recruitment and polarization; foam-cell formation; and neovascularization. mCRP has been shown to deposit in atherosclerotic plaques and damaged tissues. In recent years, the first published papers have reported the development and application of mCRP assays. Principally, these studies demonstrated the feasibility of measuring mCRP levels. With recent advances in detection techniques and the introduction of first assays, mCRP-level measurement should become more accessible and widely used. To date, anti-inflammatory therapy in atherosclerosis has targeted the NLRP3 inflammasome and upstream links of the IL-1β/IL-6/CRP axis. Large clinical trials have provided sufficient evidence to support this strategy. However, few compounds target CRP. Studies on these agents are limited to animal models or small clinical trials.
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Lv JM, Huang XP, Chen JY, Cheng B, Chen WZ, Yuan P, Wu F, Li HY. Cholesterol-binding sequence is a key regulatory motif of cellular folding and conformational activation for C-reactive protein. Mol Immunol 2022; 152:123-128. [DOI: 10.1016/j.molimm.2022.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/13/2022] [Accepted: 10/23/2022] [Indexed: 11/06/2022]
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4
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Labarrere CA, Kassab GS. Glutathione: A Samsonian life-sustaining small molecule that protects against oxidative stress, ageing and damaging inflammation. Front Nutr 2022; 9:1007816. [PMID: 36386929 PMCID: PMC9664149 DOI: 10.3389/fnut.2022.1007816] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 10/12/2022] [Indexed: 11/26/2022] Open
Abstract
Many local and systemic diseases especially diseases that are leading causes of death globally like chronic obstructive pulmonary disease, atherosclerosis with ischemic heart disease and stroke, cancer and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 19 (COVID-19), involve both, (1) oxidative stress with excessive production of reactive oxygen species (ROS) that lower glutathione (GSH) levels, and (2) inflammation. The GSH tripeptide (γ- L-glutamyl-L-cysteinyl-glycine), the most abundant water-soluble non-protein thiol in the cell (1-10 mM) is fundamental for life by (a) sustaining the adequate redox cell signaling needed to maintain physiologic levels of oxidative stress fundamental to control life processes, and (b) limiting excessive oxidative stress that causes cell and tissue damage. GSH activity is facilitated by activation of the Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) redox regulator pathway, releasing Nrf2 that regulates expression of genes controlling antioxidant, inflammatory and immune system responses. GSH exists in the thiol-reduced (>98% of total GSH) and disulfide-oxidized (GSSG) forms, and the concentrations of GSH and GSSG and their molar ratio are indicators of the functionality of the cell. GSH depletion may play a central role in inflammatory diseases and COVID-19 pathophysiology, host immune response and disease severity and mortality. Therapies enhancing GSH could become a cornerstone to reduce severity and fatal outcomes of inflammatory diseases and COVID-19 and increasing GSH levels may prevent and subdue these diseases. The life value of GSH makes for a paramount research field in biology and medicine and may be key against systemic inflammation and SARS-CoV-2 infection and COVID-19 disease. In this review, we emphasize on (1) GSH depletion as a fundamental risk factor for diseases like chronic obstructive pulmonary disease and atherosclerosis (ischemic heart disease and stroke), (2) importance of oxidative stress and antioxidants in SARS-CoV-2 infection and COVID-19 disease, (3) significance of GSH to counteract persistent damaging inflammation, inflammaging and early (premature) inflammaging associated with cell and tissue damage caused by excessive oxidative stress and lack of adequate antioxidant defenses in younger individuals, and (4) new therapies that include antioxidant defenses restoration.
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Secretory quality control constrains functional selection-associated protein structure innovation. Commun Biol 2022; 5:268. [PMID: 35338247 PMCID: PMC8956723 DOI: 10.1038/s42003-022-03220-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 03/03/2022] [Indexed: 12/26/2022] Open
Abstract
Biophysical models suggest a dominant role of structural over functional constraints in shaping protein evolution. Selection on structural constraints is linked closely to expression levels of proteins, which together with structure-associated activities determine in vivo functions of proteins. Here we show that despite the up to two orders of magnitude differences in levels of C-reactive protein (CRP) in distinct species, the in vivo functions of CRP are paradoxically conserved. Such a pronounced level-function mismatch cannot be explained by activities associated with the conserved native structure, but is coupled to hidden activities associated with the unfolded, activated conformation. This is not the result of selection on structural constraints like foldability and stability, but is achieved by folding determinants-mediated functional selection that keeps a confined carrier structure to pass the stringent eukaryotic quality control on secretion. Further analysis suggests a folding threshold model which may partly explain the mismatch between the vast sequence space and the limited structure space of proteins. The mismatch in the conserved structure but different expression levels of C-reactive protein (CRP) in distinct species is reconciled by functional selection on hidden activities of unfolded CRPs.
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Cheng B, Wu D, Wu K, Huang XP, Lv JM, Ji SR, Zhu L. Purification of Recombinant Mouse C-Reactive Protein from Pichia Pastoris GS115 by Nickel Chelating Sepharose Fast-Flow Affinity Chromatography and P-Aminophenyl Phosphoryl Choline Agarose Resin Affinity Chromatography in Tandem. J Chromatogr Sci 2021; 60:750-759. [PMID: 34625786 DOI: 10.1093/chromsci/bmab121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Indexed: 11/13/2022]
Abstract
C-reactive protein (CRP) is a circulating marker of inflammation yet with ill-defined biological functions. This is partly due to the uncharacterized activities of endogenous CRP in mice, the major animal model used to define protein function. The hurdles for purification and characterization of mouse CRP are its low circulating levels and the lack of specific antibodies. To clear these hurdles, here we developed an efficient expression system by constructing recombinant Pichia pastoris cells for secretion of native conformation mouse CRP. The recombinant expression of mouse CRP in Escherichia coli failed to yield sufficient amount of native protein, reflecting the importance of post-translational modification of glycosylation in aiding proper folding. By contrast, sufficient amount of native mouse CRP was successfully purified from P. pastoris. Preliminary purification was performed by Nickel Chelating Sepharose Fast-Flow affinity chromatography with 6 × His tags attached to the protein. Subsequently, p-Aminophenyl Phosphoryl Choline Agarose resin affinity chromatography was used for tandem purification. The purified mouse CRP showed native pentamer and capabilities of PC binding. Moreover, the 6 × His tag provides a convenient tool for detecting the interactions of mouse CRP with ligands.
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Affiliation(s)
- Bin Cheng
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou 730000, PR China
| | - Di Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou 730000, PR China
| | - Ke Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou 730000, PR China
| | - Xiao-Ping Huang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou 730000, PR China
| | - Jian-Min Lv
- MOE Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Shang-Rong Ji
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou 730000, PR China
| | - Li Zhu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou 730000, PR China
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Labarrere CA, Kassab GS. Pattern Recognition Proteins: First Line of Defense Against Coronaviruses. Front Immunol 2021; 12:652252. [PMID: 34630377 PMCID: PMC8494786 DOI: 10.3389/fimmu.2021.652252] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 08/31/2021] [Indexed: 01/08/2023] Open
Abstract
The rapid outbreak of COVID-19 caused by the novel coronavirus SARS-CoV-2 in Wuhan, China, has become a worldwide pandemic affecting almost 204 million people and causing more than 4.3 million deaths as of August 11 2021. This pandemic has placed a substantial burden on the global healthcare system and the global economy. Availability of novel prophylactic and therapeutic approaches are crucially needed to prevent development of severe disease leading to major complications both acutely and chronically. The success in fighting this virus results from three main achievements: (a) Direct killing of the SARS-CoV-2 virus; (b) Development of a specific vaccine, and (c) Enhancement of the host's immune system. A fundamental necessity to win the battle against the virus involves a better understanding of the host's innate and adaptive immune response to the virus. Although the role of the adaptive immune response is directly involved in the generation of a vaccine, the role of innate immunity on RNA viruses in general, and coronaviruses in particular, is mostly unknown. In this review, we will consider the structure of RNA viruses, mainly coronaviruses, and their capacity to affect the lungs and the cardiovascular system. We will also consider the effects of the pattern recognition protein (PRP) trident composed by (a) Surfactant proteins A and D, mannose-binding lectin (MBL) and complement component 1q (C1q), (b) C-reactive protein, and (c) Innate and adaptive IgM antibodies, upon clearance of viral particles and apoptotic cells in lungs and atherosclerotic lesions. We emphasize on the role of pattern recognition protein immune therapies as a combination treatment to prevent development of severe respiratory syndrome and to reduce pulmonary and cardiovascular complications in patients with SARS-CoV-2 and summarize the need of a combined therapeutic approach that takes into account all aspects of immunity against SARS-CoV-2 virus and COVID-19 disease to allow mankind to beat this pandemic killer.
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Affiliation(s)
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
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Narayan M. Revisiting the Formation of a Native Disulfide Bond: Consequences for Protein Regeneration and Beyond. Molecules 2020; 25:molecules25225337. [PMID: 33207635 PMCID: PMC7697891 DOI: 10.3390/molecules25225337] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 11/16/2022] Open
Abstract
Oxidative protein folding involves the formation of disulfide bonds and the regeneration of native structure (N) from the fully reduced and unfolded protein (R). Oxidative protein folding studies have provided a wealth of information on underlying physico-chemical reactions by which disulfide-bond-containing proteins acquire their catalytically active form. Initially, we review key events underlying oxidative protein folding using bovine pancreatic ribonuclease A (RNase A), bovine pancreatic trypsin inhibitor (BPTI) and hen-egg white lysozyme (HEWL) as model disulfide bond-containing folders and discuss consequential outcomes with regard to their folding trajectories. We re-examine the findings from the same studies to underscore the importance of forming native disulfide bonds and generating a “native-like” structure early on in the oxidative folding pathway. The impact of both these features on the regeneration landscape are highlighted by comparing ideal, albeit hypothetical, regeneration scenarios with those wherein a native-like structure is formed relatively “late” in the R→N trajectory. A special case where the desired characteristics of oxidative folding trajectories can, nevertheless, stall folding is also discussed. The importance of these data from oxidative protein folding studies is projected onto outcomes, including their impact on the regeneration rate, yield, misfolding, misfolded-flux trafficking from the endoplasmic reticulum (ER) to the cytoplasm, and the onset of neurodegenerative disorders.
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Affiliation(s)
- Mahesh Narayan
- The Department of Chemistry and Biochemistry, The University of Texas as El Paso, El Paso, TX 79968, USA
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Zhang Y, Cao H. Monomeric C-reactive protein affects cell injury and apoptosis through activation of p38 mitogen-activated protein kinase in human coronary artery endothelial cells. Bosn J Basic Med Sci 2020; 20:487-494. [PMID: 32358950 PMCID: PMC7664785 DOI: 10.17305/bjbms.2020.4711] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 03/31/2020] [Indexed: 01/08/2023] Open
Abstract
C-reactive protein (CRP) is an important predictor of cardiovascular events and plays a role in vascular inflammation and vessel damage. The aim of this study was to investigate the effect of pentameric CRP (pCRP) and monomeric CRP (mCRP) on the production of atherosclerosis-re-lated factors in cultured human coronary artery endothelial cells (HCAECs). HCAECs were treated with pCRP, mCRP, p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580, or transfected with p38 MAPK siRNA. Western blotting was performed to detect the expression of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), intercellular adhesion molecule-2 (ICAM-2) and vascular cell adhe-sion molecule-1 (VCAM-1). Proliferation, damage, and apoptosis of HCAECs were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, lactate dehydrogenase (LDH), and flow cytometry, respectively. mCRP suppressed VEGF and COX-2 expression and enhanced ICAM-2 and VCAM-1 expression in HCAECs, in both dose-dependent and time-dependent manner. Except at 100 μg/ml concen-tration and 20-hour or 24-hour incubation, pCRP had no apparent effects. mCRP but not pCRP induced HCAEC injury and phosphorylation of p38 MAPK, and the inhibitor SB203580 reversed the effects of mCRP. mCRP promotes injury and apoptosis of HCAECs through a p38 MAPK-dependent mechanism, which provides a new therapy for the injury of HCAECs in atherosclerosis.
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Affiliation(s)
- Yong Zhang
- Department of Vasculocardiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Hongxia Cao
- Department of Nephrology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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Madero-Ayala PA, Mares-Alejandre RE, Ramos-Ibarra MA. A molecular dynamics approach on the Y393C variant of protein disulfide isomerase A1. Chem Biol Drug Des 2020; 96:1341-1347. [PMID: 32352225 DOI: 10.1111/cbdd.13700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/03/2020] [Accepted: 04/26/2020] [Indexed: 11/28/2022]
Abstract
Human protein disulfide isomerase A1 (PDIA1) shows both catalytic (i.e., oxidoreductase) and non-catalytic (i.e., chaperone) activities and plays a crucial role in the oxidative folding of proteins within the endoplasmic reticulum. PDIA1 dysregulation is a common trait in numerous pathophysiological conditions, including neurodegenerative disorders and cancerous diseases. The 1178A>G mutation of the human PDIA1-encoding gene is a non-synonymous single nucleotide polymorphism detected in patients with Cole-Carpenter syndrome type 1 (CSS1), a particularly rare bone disease. In vitro studies showed that the encoded variant (PDIA1 Y393C) exhibits limited oxidoreductase activity. To gain knowledge on the structure-function relationship, we undertook a molecular dynamics (MD) approach to examine the structural stability of PDIA1 Y393C. Results showed that significant conformational changes are the structural consequence of the amino acid substitution Tyr>Cys at position 393 of the PDIA1 protein. This structure-based study provides further knowledge about the molecular origin of CCS1.
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Affiliation(s)
- Pablo A Madero-Ayala
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Tijuana, México
| | - Rosa E Mares-Alejandre
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Tijuana, México
| | - Marco A Ramos-Ibarra
- Grupo de Investigación en Biotecnología y Biociencias, Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Tijuana, México
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McCarthy S, Robinson J, Thalassinos K, Tabor AB. A Chemical Biology Approach to Probing the Folding Pathways of the Inhibitory Cystine Knot (ICK) Peptide ProTx-II. Front Chem 2020; 8:228. [PMID: 32309273 PMCID: PMC7145985 DOI: 10.3389/fchem.2020.00228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/10/2020] [Indexed: 11/24/2022] Open
Abstract
Peptide toxins that adopt the inhibitory cystine knot (ICK) scaffold have very stable three-dimensional structures as a result of the conformational constraints imposed by the configuration of the three disulfide bonds that are the hallmark of this fold. Understanding the oxidative folding pathways of these complex peptides, many of which are important therapeutic leads, is important in order to devise reliable synthetic routes to correctly folded, biologically active peptides. Previous research on the ICK peptide ProTx-II has shown that in the absence of an equilibrating redox buffer, misfolded intermediates form that prevent the formation of the native disulfide bond configuration. In this paper, we used tandem mass spectrometry to examine these misfolded peptides, and identified two non-native singly bridged peptides, one with a Cys(III)-Cys(IV) linkage and one with a Cys(V)-Cys(VI) linkage. Based on these results, we propose that the C-terminus of ProTx-II has an important role in initiating the folding of this peptide. To test this hypothesis, we have also studied the folding pathways of analogs of ProTx-II containing the disulfide-bond directing group penicillamine (Pen) under the same conditions. We find that placing Pen residues at the C-terminus of the ProTx-II analogs directs the folding pathway away from the singly bridged misfolded intermediates that represent a kinetic trap for the native sequence, and allows a fully oxidized final product to be formed with three disulfide bridges. However, multiple two-disulfide peptides were also produced, indicating that further study is required to fully control the folding pathways of this modified scaffold.
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Affiliation(s)
| | | | - Konstantinos Thalassinos
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom.,Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom
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Lv JM, Chen JY, Liu ZP, Yao ZY, Wu YX, Tong CS, Cheng B. Celluar Folding Determinants and Conformational Plasticity of Native C-Reactive Protein. Front Immunol 2020; 11:583. [PMID: 32296446 PMCID: PMC7137756 DOI: 10.3389/fimmu.2020.00583] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/13/2020] [Indexed: 11/13/2022] Open
Abstract
C-reactive protein (CRP) is an acute phase reactant secreted by hepatocytes as a pentamer. The structure formation of pentameric CRP has been demonstrated to proceed in a stepwise manner in live cells. Here, we further dissect the sequence determinants that underlie the key steps in cellular folding and assembly of CRP. The initial folding of CRP subunits depends on a leading sequence with a conserved dipeptide that licenses the formation of the hydrophobic core. This drives the bonding of the intra-subunit disulfide requiring a favorable niche largely conferred by a single residue within the C-terminal helix. A conserved salt bridge then mediates the assembly of folded subunits into pentamer. The pentameric assembly harbors a pronounced plasticity in inter-subunit interactions, which may form the basis for a reversible activation of CRP in inflammation. These results provide insights into how sequence constraints are evolved to dictate structure and function of CRP.
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Affiliation(s)
- Jian-Min Lv
- MOE Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, China
| | - Jun-Yao Chen
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Zu-Pei Liu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Zhen-Yu Yao
- Xi'an Key Laboratory of Children's Health and Diseases, The Affiliated Children Hospital, Children's Research Institute, Xi'an Jiaotong University, Xi'an, China
| | - Yue-Xin Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Cheng-Sen Tong
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Bin Cheng
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
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13
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Robinson PJ, Kanemura S, Cao X, Bulleid NJ. Protein secondary structure determines the temporal relationship between folding and disulfide formation. J Biol Chem 2020; 295:2438-2448. [PMID: 31953323 PMCID: PMC7039548 DOI: 10.1074/jbc.ra119.011983] [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: 11/19/2019] [Revised: 01/16/2020] [Indexed: 11/06/2022] Open
Abstract
How and when disulfide bonds form in proteins relative to the stage of their folding is a fundamental question in cell biology. Two models describe this relationship: the folded precursor model, in which a nascent structure forms before disulfides do, and the quasi-stochastic model, where disulfides form prior to folding. Here we investigated oxidative folding of three structurally diverse substrates, β2-microglobulin, prolactin, and the disintegrin domain of ADAM metallopeptidase domain 10 (ADAM10), to understand how these mechanisms apply in a cellular context. We used a eukaryotic cell-free translation system in which we could identify disulfide isomers in stalled translation intermediates to characterize the timing of disulfide formation relative to translocation into the endoplasmic reticulum and the presence of non-native disulfides. Our results indicate that in a domain lacking secondary structure, disulfides form before conformational folding through a process prone to nonnative disulfide formation, whereas in proteins with defined secondary structure, native disulfide formation occurs after partial folding. These findings reveal that the nascent protein structure promotes correct disulfide formation during cotranslational folding.
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Affiliation(s)
- Philip J Robinson
- Institute of Molecular, Cell, and Systems Biology, College of Medical Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Shingo Kanemura
- Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Xiaofei Cao
- Institute of Molecular, Cell, and Systems Biology, College of Medical Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Neil J Bulleid
- Institute of Molecular, Cell, and Systems Biology, College of Medical Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
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Zhang CM, Tan YB, Zhou HH, Ge ZB, Feng JR, Lv GB, Sun ZY, Fu Y, Wang MY. Intra-subunit Disulfide Determines the Conversion and Structural Stability of CRP Isoforms. Inflammation 2019; 43:466-477. [PMID: 31760526 DOI: 10.1007/s10753-019-01130-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
C-reactive protein (CRP) is a major human acute-phase reactant that is composed of five identical subunits. CRP dissociates into subunits at inflammatory loci forming monomeric CRP (mCRP) with substantially enhanced activities, which can be further activated by reducing the intra-subunit disulfide bond. However, conformational changes underlying the activation process of CRP are less well understood. Conformational changes accompanying the conversion of CRP to mCRP with or without reduction were examined with circular dichroism spectroscopy, fluorescence spectroscopy, electron microscopy, size-exclusion chromatography, and neoepitope expression. The conversion of CRP to mCRP follows a two-stage process. In the first stage, CRP dissociates into molten globular subunits characterized by intact secondary structure elements with greatly impaired tertiary packing. In the second stage, these intermediates completely lose their native subunit conformation and assemble into high-order aggregates. The inclusion of reductant accelerates the formation of molten globular subunits in the first step and promotes the formation of more compact aggregates in the second stage. We further show a significant contribution of electrostatic interactions to the stabilization of native CRP. The conformational features of dissociated subunits and the aggregation of mCRP may have a key impact on their activities.
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Affiliation(s)
- Chun-Miao Zhang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Yu-Bo Tan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Hai-Hong Zhou
- Gansu Provincial Cancer Hospital, Lanzhou, 730050, People's Republic of China
| | - Zhong-Bo Ge
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Jun-Rui Feng
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Guang-Bo Lv
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Zhi-Yuan Sun
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Yu Fu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Ming-Yu Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
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15
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Singh SK, Agrawal A. Functionality of C-Reactive Protein for Atheroprotection. Front Immunol 2019; 10:1655. [PMID: 31379851 PMCID: PMC6646712 DOI: 10.3389/fimmu.2019.01655] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/03/2019] [Indexed: 12/14/2022] Open
Abstract
C-reactive protein (CRP) is a pentameric molecule made up of identical monomers. CRP can be seen in three different forms: native pentameric CRP (native CRP), non-native pentameric CRP (non-native CRP), and monomeric CRP (mCRP). Both native and non-native CRP execute ligand-recognition functions for host defense. The fate of any pentameric CRP after binding to a ligand is dissociation into ligand-bound mCRP. If ligand-bound mCRP is proinflammatory, like free mCRP has been shown to be in vitro, then mCRP along with the bound ligand must be cleared from the site of inflammation. Once pentameric CRP is bound to atherogenic low-density lipoprotein (LDL), it reduces both formation of foam cells and proinflammatory effects of atherogenic LDL. A CRP mutant, that is non-native CRP, which readily binds to atherogenic LDL, has been found to be atheroprotective in a murine model of atherosclerosis. Thus, unlike statins, a drug that can lower only cholesterol levels but not CRP levels should be developed. Since non-native CRP has been shown to bind to all kinds of malformed proteins in general, it is possible that non-native CRP would be protective against all inflammatory states in which host proteins become pathogenic. If it is proven through experimentation employing transgenic mice that non-native CRP is beneficial for the host, then using a small-molecule compound to target CRP with the goal of changing the conformation of endogenous native CRP would be preferred over using recombinant non-native CRP as a biologic to treat diseases caused by pathogenic proteins such as oxidized LDL.
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Affiliation(s)
| | - Alok Agrawal
- Department of Biomedical Sciences, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
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16
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Muttathukattil AN, Singh PC, Reddy G. Role of Disulfide Bonds and Topological Frustration in the Kinetic Partitioning of Lysozyme Folding Pathways. J Phys Chem B 2019; 123:3232-3241. [PMID: 30913878 DOI: 10.1021/acs.jpcb.9b00739] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Disulfide bonds in proteins can strongly influence the folding pathways by constraining the conformational space. Lysozyme has four disulfide bonds and is widely studied for its antibacterial properties. Experiments on lysozyme infer that the protein folds through a fast and a slow pathway. However, the reasons for the kinetic partitioning in the folding pathways are not completely clear. Using a coarse-grained protein model and simulations, we show that two out of the four disulfide bonds, which are present in the α-domain of lysozyme, are responsible for the slow folding pathway. In this pathway, a kinetically trapped intermediate state, which is close to the native state, is populated. In this state, the orientations of α-helices present in the α-domain are misaligned relative to each other. The protein in this state has to partially unfold by breaking down the interhelical contacts between the misaligned helices to fold to the native state. However, the topological constraints due to the two disulfide bonds present in the α-domain make the protein less flexible, and it is trapped in this conformation for hundreds of milliseconds. On disabling these disulfide bonds, we find that the kinetically trapped intermediate state and the slow folding pathway disappear. Simulations mimicking the folding of protein without disulfide bonds under oxidative conditions show that the native disulfide bonds are formed as the protein folds, indicating that folding guides the formation of disulfide bonds. The sequence of formation of the disulfide bonds is Cys64-Cys80 → Cys76-Cys94 → Cys30-Cys115 → Cys6-Cys127. Any disulfide bond that forms before its precursor in the sequence has to break and follow the sequence for the protein to fold. These results show that lysozyme also serves as a very good model system to probe the role of disulfide bonds and topological frustration in protein folding. The predictions from the simulations can be verified by single-molecule fluorescence resonance energy transfer or single-molecule pulling experiments, which can probe heterogeneity in the folding pathways.
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Affiliation(s)
- Aswathy N Muttathukattil
- Solid State and Structural Chemistry Unit , Indian Institute of Science , Bengaluru 560012 , Karnataka , India
| | - Prashant Chandra Singh
- School of Chemical Science , Indian Association for the Cultivation of Science , 2A & 2B, Raja S.C. Mullick Road , Jadavpur, Kolkata 700032 , India
| | - Govardhan Reddy
- Solid State and Structural Chemistry Unit , Indian Institute of Science , Bengaluru 560012 , Karnataka , India
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17
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Zhang M, Liu Y, Liu Z, Wang J, Gong M, Ge H, Li X, Yang Y, Zou Z. Hyper-acidic fusion minipeptides escort the intrinsic antioxidative ability of the pattern recognition receptor CRP in non-animal organisms. Sci Rep 2019; 9:3032. [PMID: 30816172 PMCID: PMC6395739 DOI: 10.1038/s41598-019-39388-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/18/2019] [Indexed: 01/15/2023] Open
Abstract
C-reactive protein (CRP) is widely used as a biomarker of inflammation. It plays important roles in innate immunity response as a member of pattern recognition receptors, by binding oxidation-specific epitopes including some intermediates of lipid oxidative chain reaction. The inferred antioxidative ability of CRP was ever demonstrated by only few in vitro evidences, and needs to be clarified especially in vivo. Herein, we expressed human CRP in three representative non-animal organisms (Escherichia coli, Saccharomyces cerevisiae, and tobacco) inherently lacking the milieu for CRP signalling, and found CRP did possess an intrinsic antioxidative ability. Heterologous CRP could confer increased oxidative resistance in its recombinant E. coli and yeast cells and transgenic tobaccos. We also revealed a positive correlation between the antioxidative effect of CRP and its solubility. Only soluble CRP could exhibit distinct antioxidative activity, while the CRP aggregates might be instead toxic (probably pro-oxidative) to cells. Moreover, fusion with hyper-acidic minipeptides could remarkably improve CRP solubility, and meanwhile guarantee or enhance CRP antioxidative ability. These results not only provide a new insight for understanding the etiology of CRP-involved inflammations and diseases, and also endorse a potential of CRP biotechnological applications in developing new pharmaceutical therapies and improving plant oxidative resistance.
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Affiliation(s)
- Mengru Zhang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Yanjuan Liu
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, School of Life Sciences, Yunnan Normal University, Kunming, 650500, China
| | - Zhibin Liu
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Jianmei Wang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Ming Gong
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, School of Life Sciences, Yunnan Normal University, Kunming, 650500, China
| | - Hu Ge
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Xufeng Li
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Yi Yang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, China.
| | - Zhurong Zou
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, School of Life Sciences, Yunnan Normal University, Kunming, 650500, China.
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18
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Ngwa DN, Agrawal A. Structure-Function Relationships of C-Reactive Protein in Bacterial Infection. Front Immunol 2019; 10:166. [PMID: 30863393 PMCID: PMC6400226 DOI: 10.3389/fimmu.2019.00166] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 01/18/2019] [Indexed: 12/26/2022] Open
Abstract
One host defense function of C-reactive protein (CRP) is to protect against Streptococcus pneumoniae infection as shown by experiments employing murine models of pneumococcal infection. The protective effect of CRP is due to reduction in bacteremia. There is a distinct relationship between the structure of CRP and its anti-pneumococcal function. CRP is functional in both native and non-native pentameric structural conformations. In the native conformation, CRP binds to pneumococci through the phosphocholine molecules present on the C-polysaccharide of the pneumococcus and the anti-pneumococcal function probably involves the known ability of ligand-complexed CRP to activate the complement system. In the native structure-function relationship, CRP is protective only when given to mice within a few hours of the administration of pneumococci. The non-native pentameric conformation of CRP is created when CRP is exposed to conditions mimicking inflammatory microenvironments, such as acidic pH and redox conditions. In the non-native conformation, CRP binds to immobilized complement inhibitor factor H in addition to being able to bind to phosphocholine. Recent data using CRP mutants suggest that the factor H-binding function of non-native CRP is beneficial: in the non-native structure-function relationship, CRP can be given to mice any time after the administration of pneumococci irrespective of whether the pneumococci became complement-resistant or not. In conclusion, while native CRP is protective only against early stage infection, non-native CRP is protective against both early stage and late stage infections. Because non-native CRP displays phosphocholine-independent anti-pneumococcal activity, it is quite possible that CRP functions as a general anti-bacterial molecule.
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Affiliation(s)
| | - Alok Agrawal
- Department of Biomedical Sciences, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
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Bello-Perez M, Falco A, Novoa B, Perez L, Coll J. Hydroxycholesterol binds and enhances the anti-viral activities of zebrafish monomeric c-reactive protein isoforms. PLoS One 2019; 14:e0201509. [PMID: 30653529 PMCID: PMC6336239 DOI: 10.1371/journal.pone.0201509] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/28/2018] [Indexed: 01/26/2023] Open
Abstract
C-reactive proteins (CRPs) are among the faster acute-phase inflammation-responses proteins encoded by one gene (hcrp) in humans and seven genes (crp1-7) in zebrafish (Danio rerio) with importance in bacterial and viral infections. In this study, we described novel preferential bindings of 25-hydroxycholesterol (25HOCh) to CRP1-7 compared with other lipids and explored the antiviral effects of both 25HOCh and CRP1-7 against spring viremia carp virus (SVCV) infection in zebrafish. Both in silico and in vitro results confirmed the antiviral effect of 25HOCh and CRP1-7 interactions, thereby showing that the crosstalk between them differed among the zebrafish isoforms. The presence of oxidized cholesterols in human atherosclerotic plaques amplifies the importance that similar interactions may occur for vascular and/or neurodegenerative diseases during viral infections. In this context, the zebrafish model offers a genetic tool to further investigate these interactions.
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Affiliation(s)
- Melissa Bello-Perez
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández (IBMC-UMH), Elche, Spain
| | - Alberto Falco
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández (IBMC-UMH), Elche, Spain
| | - Beatriz Novoa
- Institute of Marine Research (IIM), CSIC, Vigo, Spain
| | - Luis Perez
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández (IBMC-UMH), Elche, Spain
| | - Julio Coll
- Department of Biotechnology, Instituto Nacional Investigaciones y Tecnologías Agrarias y Alimentarias, INIA, Madrid, Spain
- * E-mail:
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20
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Lv JM, Wang MY. In vitro generation and bioactivity evaluation of C-reactive protein intermediate. PLoS One 2018; 13:e0198375. [PMID: 29851992 PMCID: PMC5979025 DOI: 10.1371/journal.pone.0198375] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/17/2018] [Indexed: 12/21/2022] Open
Abstract
The conformational conversion of pentameric C-reactive protein (pCRP) to monomeric CRP (mCRP) has been shown to play important roles in the action of CRP in inflammation regulation. In vivo studies revealed the origin of mCRP and provided insights into how pCRP dissociation affected its functions. However, the interplay and exact bioactivities of CRP isoforms still remain uncertain due to the rapid conformational conversion and complex milieu in vivo. Herein, we have used surface-immobilization of pCRP to generate a preservable intermediate with dual antigenicity expression of both pCRP and mCRP. The intermediate has been further shown to exhibit modified bioactivities, such as a high affinity with solution-phase pCRP and an enhanced capacity of complement interaction. These results thus not only provide the conformational conversion details of CRP, but also propose a simple way in vitro to study how the functions of CRP are tuned by distinct isoforms.
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Affiliation(s)
- Jian-Min Lv
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, P.R. China
| | - Ming-Yu Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, P.R. China
- * E-mail:
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