51
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Gorbenko GP, Trusova V, Mizuguchi C, Saito H. Lipid Bilayer Interactions of Amyloidogenic N-Terminal Fragment of Apolipoprotein A-I Probed by Förster Resonance Energy Transfer and Molecular Dynamics Simulations. J Fluoresc 2018; 28:1037-1047. [DOI: 10.1007/s10895-018-2267-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 07/10/2018] [Indexed: 11/25/2022]
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52
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Wilson CJ, Das M, Jayaraman S, Gursky O, Engen JR. Effects of Disease-Causing Mutations on the Conformation of Human Apolipoprotein A-I in Model Lipoproteins. Biochemistry 2018; 57:4583-4596. [PMID: 30004693 DOI: 10.1021/acs.biochem.8b00538] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plasma high-density lipoproteins (HDLs) are protein-lipid nanoparticles that transport lipids and protect against atherosclerosis. Human apolipoprotein A-I (apoA-I) is the principal HDL protein whose mutations can cause either aberrant lipid metabolism or amyloid disease. Hydrogen-deuterium exchange (HDX) mass spectrometry (MS) was used to study the apoA-I conformation in model discoidal lipoproteins similar in size to large plasma HDL. We examined how point mutations associated with hereditary amyloidosis (F71Y and L170P) or atherosclerosis (L159R) influence the local apoA-I conformation in model lipoproteins. Unlike other apoA-I forms, the large particles showed minimal conformational heterogeneity, suggesting a fully extended protein conformation. Mutation-induced structural perturbations in lipid-bound protein were attenuated compared to the free protein and indicated close coupling between the two belt-forming apoA-I molecules. These perturbations propagated to distant lipoprotein sites, either increasing or decreasing their protection. This HDX MS study of large model HDL, compared with previous studies of smaller particles, ascertained that apoA-I's central region helps accommodate the protein conformation to lipoproteins of various sizes. This study also reveals that the effects of mutations on lipoprotein conformational dynamics are much weaker than those in a lipid-free protein. Interestingly, the mutation-induced perturbations propagate to distant sites nearly 10 nm away and alter their protection in ways that cannot be predicted from the lipoprotein structure and stability. We propose that long-range mutational effects are mediated by both protein and lipid and can influence lipoprotein functionality.
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Affiliation(s)
- Christopher J Wilson
- Department of Chemistry and Chemical Biology , Northeastern University , 360 Huntington Avenue , Boston , Massachusetts 02115 , United States
| | - Madhurima Das
- Department of Physiology & Biophysics , Boston University School of Medicine , 700 Albany Street , Boston , Massachusetts 02118 , United States
| | - Shobini Jayaraman
- Department of Physiology & Biophysics , Boston University School of Medicine , 700 Albany Street , Boston , Massachusetts 02118 , United States
| | - Olga Gursky
- Department of Physiology & Biophysics , Boston University School of Medicine , 700 Albany Street , Boston , Massachusetts 02118 , United States.,Amyloidosis Research Center , Boston University School of Medicine , Boston , Massachusetts 02118 , United States
| | - John R Engen
- Department of Chemistry and Chemical Biology , Northeastern University , 360 Huntington Avenue , Boston , Massachusetts 02115 , United States
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53
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Townsend D, Hughes E, Akien G, Stewart KL, Radford SE, Rochester D, Middleton DA. Epigallocatechin-3-gallate remodels apolipoprotein A-I amyloid fibrils into soluble oligomers in the presence of heparin. J Biol Chem 2018; 293:12877-12893. [PMID: 29853648 PMCID: PMC6102129 DOI: 10.1074/jbc.ra118.002038] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 05/25/2018] [Indexed: 11/06/2022] Open
Abstract
Amyloid deposits of WT apolipoprotein A-I (apoA-I), the main protein component of high-density lipoprotein, accumulate in atherosclerotic plaques where they may contribute to coronary artery disease by increasing plaque burden and instability. Using CD analysis, solid-state NMR spectroscopy, and transmission EM, we report here a surprising cooperative effect of heparin and the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG), a known inhibitor and modulator of amyloid formation, on apoA-I fibrils. We found that heparin, a proxy for glycosaminoglycan (GAG) polysaccharides that co-localize ubiquitously with amyloid in vivo, accelerates the rate of apoA-I formation from monomeric protein and associates with insoluble fibrils. Mature, insoluble apoA-I fibrils bound EGCG (KD = 30 ± 3 μm; Bmax = 40 ± 3 μm), but EGCG did not alter the kinetics of apoA-I amyloid assembly from monomer in the presence or absence of heparin. EGCG selectively increased the mobility of specific backbone and side-chain sites of apoA-I fibrils formed in the absence of heparin, but the fibrils largely retained their original morphology and remained insoluble. By contrast, fibrils formed in the presence of heparin were mobilized extensively by the addition of equimolar EGCG, and the fibrils were remodeled into soluble 20-nm-diameter oligomers with a largely α-helical structure that were nontoxic to human umbilical artery endothelial cells. These results argue for a protective effect of EGCG on apoA-I amyloid associated with atherosclerosis and suggest that EGCG-induced remodeling of amyloid may be tightly regulated by GAGs and other amyloid co-factors in vivo, depending on EGCG bioavailability.
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Affiliation(s)
- David Townsend
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB
| | - Eleri Hughes
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB
| | - Geoffrey Akien
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB
| | - Katie L Stewart
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - David Rochester
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB
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54
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Cooke AL, Morris J, Melchior JT, Street SE, Jerome WG, Huang R, Herr AB, Smith LE, Segrest JP, Remaley AT, Shah AS, Thompson TB, Davidson WS. A thumbwheel mechanism for APOA1 activation of LCAT activity in HDL. J Lipid Res 2018; 59:1244-1255. [PMID: 29773713 DOI: 10.1194/jlr.m085332] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 05/08/2018] [Indexed: 01/28/2023] Open
Abstract
APOA1 is the most abundant protein in HDL. It modulates interactions that affect HDL's cardioprotective functions, in part via its activation of the enzyme, LCAT. On nascent discoidal HDL, APOA1 comprises 10 α-helical repeats arranged in an anti-parallel stacked-ring structure that encapsulates a lipid bilayer. Previous chemical cross-linking studies suggested that these APOA1 rings can adopt at least two different orientations, or registries, with respect to each other; however, the functional impact of these structural changes is unknown. Here, we placed cysteine residues at locations predicted to form disulfide bonds in each orientation and then measured APOA1's ability to adopt the two registries during HDL particle formation. We found that most APOA1 oriented with the fifth helix of one molecule across from fifth helix of the other (5/5 helical registry), but a fraction adopted a 5/2 registry. Engineered HDLs that were locked in 5/5 or 5/2 registries by disulfide bonds equally promoted cholesterol efflux from macrophages, indicating functional particles. However, unlike the 5/5 registry or the WT, the 5/2 registry impaired LCAT cholesteryl esterification activity (P < 0.001), despite LCAT binding equally to all particles. Chemical cross-linking studies suggest that full LCAT activity requires a hybrid epitope composed of helices 5-7 on one APOA1 molecule and helices 3-4 on the other. Thus, APOA1 may use a reciprocating thumbwheel-like mechanism to activate HDL-remodeling proteins.
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Affiliation(s)
- Allison L Cooke
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - Jamie Morris
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - John T Melchior
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - Scott E Street
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - W Gray Jerome
- Departments of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Rong Huang
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - Andrew B Herr
- Division of Immunobiology and Center for Systems Immunology Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Loren E Smith
- Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Jere P Segrest
- Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Alan T Remaley
- Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Amy S Shah
- Division of Endocrinology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Thomas B Thompson
- Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45237
| | - W Sean Davidson
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
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55
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Tertiary structure of apolipoprotein A-I in nascent high-density lipoproteins. Proc Natl Acad Sci U S A 2018; 115:5163-5168. [PMID: 29712830 DOI: 10.1073/pnas.1721181115] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding the function of high-density lipoprotein (HDL) requires detailed knowledge of the structure of its primary protein, apolipoprotein A-I (APOA1). However, APOA1 flexibility and HDL heterogeneity have confounded decades of efforts to determine high-resolution structures and consistent models. Here, molecular dynamics simulations totaling 30 μs on two nascent HDLs, each with 2 APOA1 and either 160 phospholipids and 24 cholesterols or 200 phospholipids and 20 cholesterols, show that residues 1-21 of the N-terminal domains of APOA1 interact via strong salt bridges. Residues 26-43 of one APOA1 in the smaller particle form a hinge on the disc edge, which displaces the C-terminal domain of the other APOA1 to the phospholipid surface. The proposed structures are supported by chemical cross-linking, Rosetta modeling of the N-terminal domain, and analysis of the lipid-free ∆185APOA1 crystal structure. These structures provide a framework for understanding HDL maturation and revise all previous models of nascent HDL.
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56
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Dogan S, Paulus M, Forov Y, Weis C, Kampmann M, Cewe C, Kiesel I, Degen P, Salmen P, Rehage H, Tolan M. Human Apolipoprotein A1 at Solid/Liquid and Liquid/Gas Interfaces. J Phys Chem B 2018; 122:3953-3960. [PMID: 29488751 DOI: 10.1021/acs.jpcb.7b12481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An X-ray reflectivity study on the adsorption behavior of human apolipoprotein A1 (apoA1) at hydrophilic and hydrophobic interfaces is presented. It is shown that the protein interacts via electrostatic and hydrophobic interactions with the interfaces, resulting in the absorption of the protein. pH dependent measurements at the solid/liquid interface between silicon dioxide and aqueous protein solution show that in a small pH range between pH 4 and 6, adsorption is increased due to electrostatic attraction. Here, the native shape of the protein seems to be conserved. In contrast, the adsorption at the liquid/gas interface is mainly driven by hydrophobic effects, presumably by extending the hydrophobic regions of the amphipathic helices, and results in a conformational change of the protein during adsorption. However, the addition of differently charged membrane-forming lipids at the liquid/gas interface illustrates the ability of apoA1 to include lipids, resulting in a depletion of the lipids from the interface.
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57
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Fuentes LA, Beck WHJ, Tsujita M, Weers PMM. Charged Residues in the C-Terminal Domain of Apolipoprotein A-I Modulate Oligomerization. Biochemistry 2018; 57:2200-2210. [PMID: 29578333 DOI: 10.1021/acs.biochem.7b01052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Charged residues of the C-terminal domain of human apolipoprotein A-I (apoA-I) were targeted by site-directed mutagenesis. A series of mutant proteins was engineered in which lysine residues (Lys 195, 206, 208, 226, 238, and 239) or glutamate residues (Glu 234 and 235) were replaced by glutamine. The amino acid substitutions did not result in changes in secondary structure content or protein stability. Cross-linking and size-exclusion chromatography showed that the mutations resulted in reduced self-association, generating a predominantly monomeric apoA-I when five or six lysine residues were substituted. The rate of phosphatidylcholine vesicle solubilization was enhanced for all variants, with approximately a threefold rate enhancement for apoA-I lacking Lys 206, 208, 238, and 239, or Glu 234 and 235. Single or double mutations did not change the ability to protect lipolyzed low density lipoprotein from aggregation, but variants lacking >4 lysine residues were less effective in preventing lipoprotein aggregation. ApoA-I mediated cellular lipid efflux from wild-type mice macrophage foam cells was decreased for the variant with five lysine mutations. However, this protein was more effective in releasing cellular phosphatidylcholine and sphingomyelin from Abca1-null mice macrophage foam cells. This suggests that the mutations caused changes in the interaction with ABCA1 transporters and that membrane microsolubilization was primarily responsible for lipid efflux in cells lacking ABCA1. Taken together, this study indicates that ionic interactions in the C-terminal domain of apoA-I favor self-association and that monomeric apoA-I is more active in solubilizing phospholipid bilayers.
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Affiliation(s)
- Lukas A Fuentes
- Department of Chemistry and Biochemistry , California State University Long Beach , Long Beach , California 90840 , United States
| | - Wendy H J Beck
- Department of Chemistry and Biochemistry , California State University Long Beach , Long Beach , California 90840 , United States
| | - Maki Tsujita
- Department of Biochemistry , Nagoya City University Graduate School of Medical Sciences , Aichi 467-8601 , Japan
| | - Paul M M Weers
- Department of Chemistry and Biochemistry , California State University Long Beach , Long Beach , California 90840 , United States
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58
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Witkowski A, Chan GKL, Boatz JC, Li NJ, Inoue AP, Wong JC, van der Wel PCA, Cavigiolio G. Methionine oxidized apolipoprotein A-I at the crossroads of HDL biogenesis and amyloid formation. FASEB J 2018; 32:3149-3165. [PMID: 29401604 DOI: 10.1096/fj.201701127r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Apolipoprotein A-I (apoA-I) shares with other exchangeable apolipoproteins a high level of structural plasticity. In the lipid-free state, the apolipoprotein amphipathic α-helices interact intra- and intermolecularly, providing structural stabilization by self-association. We have reported that lipid-free apoA-I becomes amyloidogenic upon physiologically relevant (myeloperoxidase-mediated) Met oxidation. In this study, we established that Met oxidation promotes amyloidogenesis by reducing the stability of apoA-I monomers and irreversibly disrupting self-association. The oxidized apoA-I monomers also exhibited increased cellular cholesterol release capacity and stronger association with macrophages, compared to nonoxidized apoA-I. Of physiologic relevance, preformed oxidized apoA-I amyloid fibrils induced amyloid formation in nonoxidized apoA-I. This process was enhanced when self-association of nonoxidized apoA-I was disrupted by thermal treatment. Solid state NMR analysis revealed that aggregates formed by seeded nonoxidized apoA-I were structurally similar to those formed by the oxidized protein, featuring a β-structure-rich amyloid fold alongside α-helices retained from the native state. In atherosclerotic lesions, the conditions that promote apoA-I amyloid formation are readily available: myeloperoxidase, active oxygen species, low pH, and high concentration of lipid-free apoA-I. Our results suggest that even partial Met oxidation of apoA-I can nucleate amyloidogenesis, thus sequestering and inactivating otherwise antiatherogenic and HDL-forming apoA-I.-Witkowski, A., Chan, G. K. L., Boatz, J. C., Li, N. J., Inoue, A. P., Wong, J. C., van der Wel, P. C. A., Cavigiolio, G. Methionine oxidized apolipoprotein A-I at the crossroads of HDL biogenesis and amyloid formation.
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Affiliation(s)
- Andrzej Witkowski
- Children's Hospital Oakland Research Institute (CHORI), Oakland, California, USA
| | - Gary K L Chan
- Children's Hospital Oakland Research Institute (CHORI), Oakland, California, USA
| | - Jennifer C Boatz
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Nancy J Li
- Children's Hospital Oakland Research Institute (CHORI), Oakland, California, USA
| | - Ayuka P Inoue
- Children's Hospital Oakland Research Institute (CHORI), Oakland, California, USA
| | - Jaclyn C Wong
- Children's Hospital Oakland Research Institute (CHORI), Oakland, California, USA
| | | | - Giorgio Cavigiolio
- Children's Hospital Oakland Research Institute (CHORI), Oakland, California, USA
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59
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Gorshkova IN, Mei X, Atkinson D. Arginine 123 of apolipoprotein A-I is essential for lecithin:cholesterol acyltransferase activity. J Lipid Res 2017; 59:348-356. [PMID: 29208698 DOI: 10.1194/jlr.m080986] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/29/2017] [Indexed: 01/10/2023] Open
Abstract
ApoA-I activates LCAT that converts lipoprotein cholesterol to cholesteryl ester (CE). Molecular dynamic simulations suggested earlier that helices 5 of two antiparallel apoA-I molecules on discoidal HDL form an amphipathic tunnel for migration of acyl chains and unesterified cholesterol to the active sites of LCAT. Our recent crystal structure of Δ(185-243)apoA-I showed the tunnel formed by helices 5/5, with two positively charged residues arginine 123 positioned at the edge of the hydrophobic tunnel. We hypothesized that these uniquely positioned residues Arg123 are poised for interaction with fatty acids produced by LCAT hydrolysis of the sn-2 chains of phosphatidylcholine, thus positioning the fatty acids for esterification to cholesterol. To test the importance of Arg123 for LCAT phospholipid hydrolysis and CE formation, we generated apoA-I[R123A] and apoA-I[R123E] mutants and made discoidal HDL with the mutants and WT apoA-I. Neither mutation of Arg123 changed the particle composition or size, or the protein conformation or stability. However, both mutations of Arg123 significantly reduced LCAT catalytic efficiency and the apparent Vmax for CE formation without affecting LCAT phospholipid hydrolysis. A control mutation, apoA-I[R131A], did not affect LCAT phospholipid hydrolysis or CE formation. These data suggest that Arg123 of apoA-I on discoidal HDL participates in LCAT-mediated cholesterol esterification.
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Affiliation(s)
- Irina N Gorshkova
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
| | - Xiaohu Mei
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
| | - David Atkinson
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
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60
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Gaglione R, Smaldone G, Di Girolamo R, Piccoli R, Pedone E, Arciello A. Cell milieu significantly affects the fate of AApoAI amyloidogenic variants: predestination or serendipity? Biochim Biophys Acta Gen Subj 2017; 1862:377-384. [PMID: 29174954 DOI: 10.1016/j.bbagen.2017.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 11/17/2017] [Accepted: 11/21/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Specific apolipoprotein A-I variants are associated to severe hereditary amyloidoses. The organ distribution of AApoAI amyloidosis seems to depend on the position of the mutation, since mutations in residues from 1 to 75 are mainly associated to hepatic and renal amyloidosis, while mutations in residues from 173 to 178 are mostly responsible for cardiac, laryngeal, and cutaneous amyloidosis. Molecular bases of this tissue specificity are still poorly understood, but it is increasingly emerging that protein destabilization induced by amyloidogenic mutations is neither necessary nor sufficient for amyloidosis development. METHODS By using a multidisciplinary approach, including circular dichroism, dynamic light scattering, spectrofluorometric and atomic force microscopy analyses, the effect of target cells on the conformation and fibrillogenic pathway of the two AApoAI amyloidogenic variants AApoAIL75P and AApoAIL174S has been monitored. RESULTS Our data show that specific cell milieus selectively affect conformation, aggregation propensity and fibrillogenesis of the two AApoAI amyloidogenic variants. CONCLUSIONS An intriguing picture emerged indicating that defined cell contexts selectively induce fibrillogenesis of specific AApoAI variants. GENERAL SIGNIFICANCE An innovative methodological approach, based on the use of whole intact cells to monitor the effects of cell context on AApoAI variants fibrillogenic pathway, has been set up.
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Affiliation(s)
- Rosa Gaglione
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy
| | | | - Rocco Di Girolamo
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy
| | - Renata Piccoli
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; Istituto Nazionale di Biostrutture e Biosistemi (INBB), Italy
| | - Emilia Pedone
- Istituto di Biostrutture e Bioimmagini, CNR, Naples, Italy; Research Centre on Bioactive Peptides (CIRPeB), University of Naples Federico II, Via Mezzocannone 16, 80134 Naples, Italy.
| | - Angela Arciello
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; Istituto Nazionale di Biostrutture e Biosistemi (INBB), Italy.
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61
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Melchior JT, Walker RG, Cooke AL, Morris J, Castleberry M, Thompson TB, Jones MK, Song HD, Rye KA, Oda MN, Sorci-Thomas MG, Thomas MJ, Heinecke JW, Mei X, Atkinson D, Segrest JP, Lund-Katz S, Phillips MC, Davidson WS. A consensus model of human apolipoprotein A-I in its monomeric and lipid-free state. Nat Struct Mol Biol 2017; 24:1093-1099. [PMID: 29131142 PMCID: PMC5749415 DOI: 10.1038/nsmb.3501] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 10/06/2017] [Indexed: 11/09/2022]
Abstract
Apolipoprotein (apo)A-I is an organizing scaffold protein that is critical to high-density lipoprotein (HDL) structure and metabolism, probably mediating many of its cardioprotective properties. However, HDL biogenesis is poorly understood, as lipid-free apoA-I has been notoriously resistant to high-resolution structural study. Published models from low-resolution techniques share certain features but vary considerably in shape and secondary structure. To tackle this central issue in lipoprotein biology, we assembled a team of structural biologists specializing in apolipoproteins and set out to build a consensus model of monomeric lipid-free human apoA-I. Combining novel and published cross-link constraints, small-angle X-ray scattering (SAXS), hydrogen-deuterium exchange (HDX) and crystallography data, we propose a time-averaged model consistent with much of the experimental data published over the last 40 years. The model provides a long-sought platform for understanding and testing details of HDL biogenesis, structure and function.
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Affiliation(s)
- John T Melchior
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Ryan G Walker
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Allison L Cooke
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jamie Morris
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Mark Castleberry
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Thomas B Thompson
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Martin K Jones
- Department of Medicine, Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Hyun D Song
- Department of Medicine, Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kerry-Anne Rye
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Michael N Oda
- Children's Hospital Oakland Research Institute, Oakland, California, USA
| | - Mary G Sorci-Thomas
- Department of Medicine, Section on Endocrinology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Michael J Thomas
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Jay W Heinecke
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Xiaohu Mei
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts, USA
| | - David Atkinson
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Jere P Segrest
- Department of Medicine, Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Sissel Lund-Katz
- Division of Translational Medicine and Human Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michael C Phillips
- Division of Translational Medicine and Human Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - W Sean Davidson
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio, USA
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62
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Zannis VI, Su S, Fotakis P. Role of apolipoproteins, ABCA1 and LCAT in the biogenesis of normal and aberrant high density lipoproteins. J Biomed Res 2017; 31:471. [PMID: 29109329 PMCID: PMC6307667 DOI: 10.7555/jbr.31.20160082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/30/2016] [Indexed: 12/28/2022] Open
Abstract
In this review, we focus on the pathway of biogenesis of HDL, the essential role of apoA-I, ATP binding cassette transporter A1 (ABCA1), and lecithin: cholesterol acyltransferase (LCAT) in the formation of plasma HDL; the generation of aberrant forms of HDL containing mutant apoA-I forms and the role of apoA-IV and apoE in the formation of distinct HDL subpopulations. The biogenesis of HDL requires functional interactions of the ABCA1 with apoA-I (and to a lesser extent with apoE and apoA-IV) and subsequent interactions of the nascent HDL species thus formed with LCAT. Mutations in apoA-I, ABCA1 and LCAT either prevent or impair the formation of HDL and may also affect the functionality of the HDL species formed. Emphasis is placed on three categories of apoA-I mutations. The first category describes a unique bio-engineered apoA-I mutation that disrupts interactions between apoA-I and ABCA1 and generates aberrant preβ HDL subpopulations that cannot be converted efficiently to α subpopulations by LCAT. The second category describes natural and bio-engineered apoA-I mutations that generate preβ and small size α4 HDL subpopulations, and are associated with low plasma HDL levels. These phenotypes can be corrected by excess LCAT. The third category describes bio-engineered apoA-I mutations that induce hypertriglyceridemia that can be corrected by excess lipoprotein lipase and also have defective maturation of HDL. The HDL phenotypes described here may serve in the future for diagnosis, prognoses and potential treatment of abnormalities that affect the biogenesis and functionality of HDL.
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Affiliation(s)
- Vassilis I. Zannis
- . Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
- . Department University of Crete, School of Medicine, Heraklion, Crete, Greece
| | - Shi Su
- . Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
| | - Panagiotis Fotakis
- . Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
- . Department University of Crete, School of Medicine, Heraklion, Crete, Greece
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63
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Zhu L, Petrlova J, Gysbers P, Hebert H, Wallin S, Jegerschöld C, Lagerstedt JO. Structures of apolipoprotein A-I in high density lipoprotein generated by electron microscopy and biased simulations. Biochim Biophys Acta Gen Subj 2017; 1861:2726-2738. [DOI: 10.1016/j.bbagen.2017.07.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/18/2017] [Accepted: 07/24/2017] [Indexed: 10/19/2022]
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64
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Apolipoprotein A-I attenuates LL-37-induced endothelial cell cytotoxicity. Biochem Biophys Res Commun 2017; 493:71-76. [DOI: 10.1016/j.bbrc.2017.09.072] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 09/14/2017] [Indexed: 12/12/2022]
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65
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Vus K, Girych M, Trusova V, Gorbenko G, Kinnunen P, Mizuguchi C, Saito H. Fluorescence study of the effect of the oxidized phospholipids on amyloid fibril formation by the apolipoprotein A-I N-terminal fragment. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.09.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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66
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Synchrotron radiation circular dichroism spectroscopy reveals structural divergences in HDL-bound apoA-I variants. Sci Rep 2017; 7:13540. [PMID: 29051568 PMCID: PMC5648894 DOI: 10.1038/s41598-017-13878-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 10/03/2017] [Indexed: 12/15/2022] Open
Abstract
Apolipoprotein A-I (apoA-I) in high-density lipoprotein (HDL) provides cardiovascular protection. Synchrotron radiation circular dichroism (SRCD) spectroscopy was used to analyze the dynamic solution structure of the apoA-I protein in the apo- and HDL-states and the protein structure conversion in HDL formation. Wild-type apoA-I protein was compared to human variants that either are protective (R173C, Milano) or lead to increased risk for ischaemic heart disease (A164S). Comparable secondary structure distributions in the HDL particles, including significant levels of beta strand/turn, were observed. ApoA-I Milano in HDL displayed larger size heterogeneity, increased protein flexibility, and an altered lipid-binding profile, whereas the apoA-I A164S in HDL showed decrease thermal stability, potentially linking the intrinsic HDL propensities of the variants to disease risk.
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67
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Del Giudice R, Domingo-Espín J, Iacobucci I, Nilsson O, Monti M, Monti DM, Lagerstedt JO. Structural determinants in ApoA-I amyloidogenic variants explain improved cholesterol metabolism despite low HDL levels. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3038-3048. [PMID: 28887204 DOI: 10.1016/j.bbadis.2017.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 11/19/2022]
Abstract
Twenty Apolipoprotein A-I (ApoA-I) variants are responsible for a systemic hereditary amyloidosis in which protein fibrils can accumulate in different organs, leading to their failure. Several ApoA-I amyloidogenic mutations are also associated with hypoalphalipoproteinemia, low ApoA-I and high-density lipoprotein (HDL)-cholesterol plasma levels; however, subjects affected by ApoA-I-related amyloidosis do not show a higher risk of cardiovascular diseases (CVD). The structural features, the lipid binding properties and the functionality of four ApoA-I amyloidogenic variants were therefore inspected in order to clarify the paradox observed in the clinical phenotype of the affected subjects. Our results show that ApoA-I amyloidogenic variants are characterized by a different oligomerization pattern and that the position of the mutation in the ApoA-I sequence affects the molecular structure of the formed HDL particles. Although lipidation increases ApoA-I proteins stability, all the amyloidogenic variants analyzed show a lower affinity for lipids, both in vitro and in ex vivo mouse serum. Interestingly, the lower efficiency at forming HDL particles is compensated by a higher efficiency at catalysing cholesterol efflux from macrophages. The decreased affinity of ApoA-I amyloidogenic variants for lipids, together with the increased efficiency in the cholesterol efflux process, could explain why, despite the unfavourable lipid profile, patients affected by ApoA-I related amyloidosis do not show a higher CVD risk.
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Affiliation(s)
- Rita Del Giudice
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden.
| | - Joan Domingo-Espín
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden
| | - Ilaria Iacobucci
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; CEINGE Biotecnologie Avanzate, 80145 Naples, Italy
| | - Oktawia Nilsson
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden
| | - Maria Monti
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; Istituto Nazionale di Biostrutture e Biosistemi (INBB), Rome, Italy
| | - Daria Maria Monti
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy; Istituto Nazionale di Biostrutture e Biosistemi (INBB), Rome, Italy
| | - Jens O Lagerstedt
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden.
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68
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Lek MT, Cruz S, Ibe NU, Beck WHJ, Bielicki JK, Weers PMM, Narayanaswami V. Swapping the N- and C-terminal domains of human apolipoprotein E3 and AI reveals insights into their structure/activity relationship. PLoS One 2017. [PMID: 28644829 PMCID: PMC5482431 DOI: 10.1371/journal.pone.0178346] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Apolipoprotein (apo) E3 and apoAI are exchangeable apolipoproteins that play a dominant role in regulating plasma lipoprotein metabolism. ApoE3 (299 residues) is composed of an N-terminal (NT) domain bearing a 4-helix bundle and a C-terminal (CT) domain bearing a series of amphipathic α-helices. ApoAI (243 residues) also comprises a highly helical NT domain and a less structured CT tail. The objective of this study was to understand their structural and functional role by generating domain swapped chimeras: apoE3-NT/apoAI-CT and apoAI-NT/apoE-CT. The bacterially overexpressed chimeras were purified by affinity chromatography and their identity confirmed by immunoblotting and mass spectrometry. Their α-helical content was comparable to that of the parent proteins. ApoE3-NT/apoAI-CT retained the denaturation profile of apoE3 NT domain, with apoAI CT tail eliciting a relatively unstructured state; its lipid binding ability improved dramatically compared to apoE3 indicative of a significant role of apoAI CT tail in lipid binding interaction. The LDL receptor interaction and ability to promote ABCA1-mediated cholesterol efflux of apoE3-NT/apoAI-CT was comparable to that of apoE3. In contrast, apoAI-NT/apoE-CT elicited an unfolding pattern and lipid binding ability that were similar to that of apoAI. As expected, DMPC/apoAI-NT/apoE-CT discoidal particles did not elicit LDLr binding ability, and promoted SR-B1 mediated cellular uptake of lipids to a limited extent. However, apoAI-NT/apoE-CT displayed an enhanced ability to promote cholesterol efflux compared to apoAI, indicative of a significant role for apoE CT domain in mediating this function. Together, these results indicate that the functional attributes of apoAI and apoE3 can be conferred on each other and that NT-CT domain interactions significantly modulate their structure and function.
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Affiliation(s)
- Mark T. Lek
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Siobanth Cruz
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Nnejiuwa U. Ibe
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Wendy H. J. Beck
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - John K. Bielicki
- Donner Laboratory, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Paul M. M. Weers
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Vasanthy Narayanaswami
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
- * E-mail:
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69
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Kimura H, Mikawa S, Mizuguchi C, Horie Y, Morita I, Oyama H, Ohgita T, Nishitsuji K, Takeuchi A, Lund-Katz S, Akaji K, Kobayashi N, Saito H. Immunochemical Approach for Monitoring of Structural Transition of ApoA-I upon HDL Formation Using Novel Monoclonal Antibodies. Sci Rep 2017; 7:2988. [PMID: 28592796 PMCID: PMC5462821 DOI: 10.1038/s41598-017-03208-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/24/2017] [Indexed: 11/24/2022] Open
Abstract
Apolipoprotein A-I (apoA-I) undergoes a large conformational reorganization during remodeling of high-density lipoprotein (HDL) particles. To detect structural transition of apoA-I upon HDL formation, we developed novel monoclonal antibodies (mAbs). Splenocytes from BALB/c mice immunized with a recombinant human apoA-I, with or without conjugation with keyhole limpet hemocyanin, were fused with P3/NS1/1-Ag4-1 myeloma cells. After the HAT-selection and cloning, we established nine hybridoma clones secreting anti-apoA-I mAbs in which four mAbs recognize epitopes on the N-terminal half of apoA-I while the other five mAbs recognize the central region. ELISA and bio-layer interferometry measurements demonstrated that mAbs whose epitopes are within residues 1–43 or 44–65 obviously discriminate discoidal and spherical reconstituted HDL particles despite their great reactivities to lipid-free apoA-I and plasma HDL, suggesting the possibility of these mAbs to detect structural transition of apoA-I on HDL. Importantly, a helix-disrupting mutation of W50R into residues 44–65 restored the immunoreactivity of mAbs whose epitope being within residues 44–65 against reconstituted HDL particles, indicating that these mAbs specifically recognize the epitope region in a random coil state. These results encourage us to develop mAbs targeting epitopes in the N-terminal residues of apoA-I as useful probes for monitoring formation and remodeling of HDL particles.
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Affiliation(s)
- Hitoshi Kimura
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan.,Graduate School of Pharmaceutical Sciences, Tokushima University, 1-78-1 Shomachi, Tokushima, 770-8505, Japan
| | - Shiho Mikawa
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan.,Graduate School of Pharmaceutical Sciences, Tokushima University, 1-78-1 Shomachi, Tokushima, 770-8505, Japan
| | - Chiharu Mizuguchi
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan.,Graduate School of Pharmaceutical Sciences, Tokushima University, 1-78-1 Shomachi, Tokushima, 770-8505, Japan
| | - Yuki Horie
- Department of Bioanalytical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Izumi Morita
- Department of Bioanalytical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Hiroyuki Oyama
- Department of Bioanalytical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Takashi Ohgita
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan
| | - Kazuchika Nishitsuji
- Department of Molecular Pathology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Atsuko Takeuchi
- Analytical Laboratory, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Sissel Lund-Katz
- Lipid Research Group, Gastroenterology, Hepatology and Nutrition Division, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, 19104-4318, USA
| | - Kenichi Akaji
- Department of Medicinal Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan
| | - Norihiro Kobayashi
- Department of Bioanalytical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Hiroyuki Saito
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan.
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70
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Lucato CM, Lupton CJ, Halls ML, Ellisdon AM. Amyloidogenicity at a Distance: How Distal Protein Regions Modulate Aggregation in Disease. J Mol Biol 2017; 429:1289-1304. [PMID: 28342736 DOI: 10.1016/j.jmb.2017.03.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/12/2017] [Accepted: 03/14/2017] [Indexed: 12/14/2022]
Abstract
The misfolding of proteins to form amyloid is a key pathological feature of several progressive, and currently incurable, diseases. A mechanistic understanding of the pathway from soluble, native protein to insoluble amyloid is crucial for therapeutic design, and recent efforts have helped to elucidate the key molecular events that trigger protein misfolding. Generally, either global or local structural perturbations occur early in amyloidogenesis to expose aggregation-prone regions of the protein that can then self-associate to form toxic oligomers. Surprisingly, these initiating structural changes are often caused or influenced by protein regions distal to the classically amyloidogenic sequences. Understanding the importance of these distal regions in the pathogenic process has highlighted many remaining knowledge gaps regarding the precise molecular events that occur in classic aggregation pathways. In this review, we discuss how these distal regions can influence aggregation in disease and the recent technical and conceptual advances that have allowed this insight.
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Affiliation(s)
- Christina M Lucato
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Christopher J Lupton
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Andrew M Ellisdon
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia.
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71
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Townsend D, Hughes E, Hussain R, Siligardi G, Baldock S, Madine J, Middleton DA. Heparin and Methionine Oxidation Promote the Formation of Apolipoprotein A-I Amyloid Comprising α-Helical and β-Sheet Structures. Biochemistry 2017; 56:1632-1644. [DOI: 10.1021/acs.biochem.6b01120] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- David Townsend
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Eleri Hughes
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Rohanah Hussain
- Diamond Light Source Ltd., Diamond House, Harwell Science & Innovation Campus, Didcot OX11 0DE, Oxon, England
| | - Giuliano Siligardi
- Diamond Light Source Ltd., Diamond House, Harwell Science & Innovation Campus, Didcot OX11 0DE, Oxon, England
| | - Sarah Baldock
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Jillian Madine
- Department of Biochemistry, Institute
of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - David A. Middleton
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom
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72
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Raghavendra AJ, Alsaleh N, Brown JM, Podila R. Charge-transfer interactions induce surface dependent conformational changes in apolipoprotein biocorona. Biointerphases 2017; 12:02D402. [PMID: 28269991 PMCID: PMC5346100 DOI: 10.1116/1.4977064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/18/2017] [Accepted: 02/09/2017] [Indexed: 12/12/2022] Open
Abstract
Upon introduction into a biological system, engineered nanomaterials (ENMs) rapidly associate with a variety of biomolecules such as proteins and lipids to form a biocorona. The presence of "biocorona" influences nano-bio interactions considerably, and could ultimately result in altered biological responses. Apolipoprotein A-I (ApoA-I), the major constituent of high-density lipoprotein (HDL), is one of the most prevalent proteins found in ENM-biocorona irrespective of ENM nature, size, and shape. Given the importance of ApoA-I in HDL and cholesterol transport, it is necessary to understand the mechanisms of ApoA-I adsorption and the associated structural changes for assessing consequences of ENM exposure. Here, the authors used a comprehensive array of microscopic and spectroscopic tools to elucidate the interactions between ApoA-I and 100 nm Ag nanoparticles (AgNPs) with four different surface functional groups. The authors found that the protein adsorption and secondary structural changes are highly dependent on the surface functionality. Our electrochemical studies provided new evidence for charge transfer interactions that influence ApoA-I unfolding. While the unfolding of ApoA-I on AgNPs did not significantly change their uptake and short-term cytotoxicity, the authors observed that it strongly altered the ability of only some AgNPs to generate of reactive oxygen species. Our results shed new light on the importance of surface functionality and charge transfer interactions in biocorona formation.
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Affiliation(s)
- Achyut J Raghavendra
- Laboratory of Nano-Biophysics, Clemson Nanomaterials Center, Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634
| | - Nasser Alsaleh
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Science, University of Colorado-Anschutz Medical Campus, Aurora, Colorado 80045
| | - Jared M Brown
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Science, University of Colorado-Anschutz Medical Campus, Aurora, Colorado 80045
| | - Ramakrishna Podila
- Laboratory of Nano-Biophysics, Clemson Nanomaterials Center, Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634 and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson, South Carolina 29625
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73
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Das M, Wilson CJ, Mei X, Wales T, Engen JR, Gursky O. Structural stability and local dynamics in disease-causing mutants of human apolipoprotein a-I: what makes the protein amyloidogenic? Amyloid 2017; 24:11-12. [PMID: 28042708 PMCID: PMC5557347 DOI: 10.1080/13506129.2016.1269737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Madhurima Das
- a Department of Physiology & Biophysics , Boston University School of Medicine , Boston , MA , USA and
| | | | - Xiaohu Mei
- a Department of Physiology & Biophysics , Boston University School of Medicine , Boston , MA , USA and
| | - Thomas Wales
- b Department of Chemistry , Northeastern University , Boston , MA , USA
| | - John R Engen
- b Department of Chemistry , Northeastern University , Boston , MA , USA
| | - Olga Gursky
- a Department of Physiology & Biophysics , Boston University School of Medicine , Boston , MA , USA and
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74
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Gorshkova IN, Atkinson D. Increased Binding of Apolipoproteins A-I and E4 to Triglyceride-Rich Lipoproteins is linked to Induction of Hypertriglyceridemia. JSM ATHEROSCLEROSIS 2017; 2:1026. [PMID: 28597004 PMCID: PMC5460632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Hypertriglyceridemia (HTG) is an independent factor of atherosclerotic cardiovascular disease and a hallmark of many metabolic disorders. However, the molecular etiology of HTG is still largely unknown. In mice, severe HTG may be induced by expression of specific mutants of apolipoprotein (apo) A-I or wild type (WT) apoE4. Expression of a certain apoE4 mutant results in mild HTG, while expression of another apoE4 mutant or WT apoA-I results in normal plasma triglyceride (TG) levels. Biophysical studies of the apoA-I and apoE4 forms associated with HTG help better understand the molecular mechanisms of induction of HTG by these proteins. The studies show that the apoA-I and apoE4 forms that induce HTG have a destabilized and more loosely folded conformation in solution than their counterparts not associated with HTG. Disruption of the protein salt bridge networks by the mutations is likely responsible for the observed structural changes. Each apoA-I and apoE4 form that induced HTG show enhanced binding to model TG-rich particles. HTG appeared to positively correlate with the apolipoprotein ability to bind to TG-rich particles. This implies that in vivo, the conformational changes in the apolipoproteins that induce HTG facilitate their binding to plasma TG-rich lipoproteins. We discuss metabolic pathways leading to the development of HTG that may result from enhanced binding of the apolipoproteins to TG-rich lipoproteins in circulation. While various factors may be involved in the development of HTG in humans, it is possible that structural alterations that increase affinity of apolipoproteins to TG-rich lipoproteins may contribute to some cases of this disorder.
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Affiliation(s)
- Irina N. Gorshkova
- Corresponding author: Irina N. Gorshkova, Department
of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street,
Boston, Massachusetts 02118, USA, Tel: 1-617-638-4207;
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75
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Bibow S, Polyhach Y, Eichmann C, Chi CN, Kowal J, Albiez S, McLeod RA, Stahlberg H, Jeschke G, Güntert P, Riek R. Solution structure of discoidal high-density lipoprotein particles with a shortened apolipoprotein A-I. Nat Struct Mol Biol 2016; 24:187-193. [DOI: 10.1038/nsmb.3345] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 11/29/2016] [Indexed: 01/08/2023]
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76
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Oda MN. Lipid-free apoA-I structure - Origins of model diversity. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:221-233. [PMID: 27890580 DOI: 10.1016/j.bbalip.2016.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 10/20/2016] [Accepted: 11/20/2016] [Indexed: 01/22/2023]
Abstract
Apolipoprotein A-I (apoA-I) is a prominent member of the exchangeable apolipoprotein class of proteins, capable of transitioning between lipid-bound and lipid-free states. It is the primary structural and functional protein of high density lipoprotein (HDL). Lipid-free apoA-I is critical to de novo HDL formation as it is the preferred substrate of the lipid transporter, ATP Binding Cassette Transporter A1 (ABCA1) Remaley et al. (2001) [1]. Lipid-free apoA-I is an important element in reverse cholesterol transport and comprehension of its structure is a core issue in our understanding of cholesterol metabolism. However, lipid-free apoA-I is highly conformationally dynamic making it a challenging subject for structural analysis. Over the past 20years there have been significant advances in overcoming the dynamic nature of lipid-free apoA-I, which have resulted in a multitude of proposed conformational models.
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Affiliation(s)
- Michael N Oda
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, United States.
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77
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Arciello A, Piccoli R, Monti DM. Apolipoprotein A-I: the dual face of a protein. FEBS Lett 2016; 590:4171-4179. [DOI: 10.1002/1873-3468.12468] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/12/2016] [Accepted: 10/24/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Angela Arciello
- Department of Chemical Sciences; University of Naples Federico II; Italy
- Istituto Nazionale di Biostrutture e Biosistemi (INBB); Rome Italy
| | - Renata Piccoli
- Department of Chemical Sciences; University of Naples Federico II; Italy
- Istituto Nazionale di Biostrutture e Biosistemi (INBB); Rome Italy
| | - Daria Maria Monti
- Department of Chemical Sciences; University of Naples Federico II; Italy
- Istituto Nazionale di Biostrutture e Biosistemi (INBB); Rome Italy
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78
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Pollard RD, Fulp B, Sorci-Thomas MG, Thomas MJ. High-Density Lipoprotein Biogenesis: Defining the Domains Involved in Human Apolipoprotein A-I Lipidation. Biochemistry 2016; 55:4971-81. [PMID: 27501467 DOI: 10.1021/acs.biochem.6b00347] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The first step in removing cholesterol from a cell is the ATP-binding cassette transporter 1 (ABCA1)-driven transfer of cholesterol to lipid-free or lipid-poor apolipoprotein A-I (apoA-I), which yields cholesterol-rich nascent high-density lipoprotein (nHDL) that then matures in plasma to spherical, cholesteryl ester-rich HDL. However, lipid-free apoA-I has a three-dimensional (3D) conformation that is significantly different from that of lipidated apoA-I on nHDL. By comparing the lipid-free apoA-I 3D conformation of apoA-I to that of 9-14 nm diameter nHDL, we formulated the hypothetical helical domain transitions that might drive particle formation. To test the hypothesis, ten apoA-I mutants were prepared that contained two strategically placed cysteines several of which could form intramolecular disulfide bonds and others that could not form these bonds. Mass spectrometry was used to identify amino acid sequence and intramolecular disulfide bond formation. Recombinant HDL (rHDL) formation was assessed with this group of apoA-I mutants. ABCA1-driven nHDL formation was measured in four mutants and wild-type apoA-I. The mutants contained cysteine substitutions in one of three regions: the N-terminus, amino acids 34 and 55 (E34C to S55C), central domain amino acids 104 and 162 (F104C to H162C), and the C-terminus, amino acids 200 and 233 (L200C to L233C). Mutants were studied in the locked form, with an intramolecular disulfide bond present, or unlocked form, with the cysteine thiol blocked by alkylation. Only small amounts of rHDL or nHDL were formed upon locking the central domain. We conclude that both the N- and C-terminal ends assist in the initial steps in lipid acquisition, but that opening of the central domain was essential for particle formation.
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Affiliation(s)
- Ricquita D Pollard
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine , Winston-Salem, North Carolina 27101, United States
| | - Brian Fulp
- Department of Biochemistry, Wake Forest School of Medicine , Winston-Salem, North Carolina 27101, United States
| | - Mary G Sorci-Thomas
- Departments of Medicine, Division of Endocrinology, Pharmacology and Toxicology, and Blood Research Institute, BloodCenter of Wisconsin, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
| | - Michael J Thomas
- Department of Pharmacology and Toxicology, Medical College of Wisconsin , 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
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79
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Almer G, Mangge H, Zimmer A, Prassl R. Lipoprotein-Related and Apolipoprotein-Mediated Delivery Systems for Drug Targeting and Imaging. Curr Med Chem 2016; 22:3631-51. [PMID: 26180001 PMCID: PMC5403973 DOI: 10.2174/0929867322666150716114625] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 06/19/2015] [Accepted: 07/13/2015] [Indexed: 01/27/2023]
Abstract
The integration of lipoprotein-related or apolipoprotein-targeted nanoparticles as pharmaceutical carriers opens new therapeutic and diagnostic avenues in nanomedicine. The concept is to exploit the intrinsic characteristics of lipoprotein particles as being the natural transporter of apolar lipids and fat in human circulation. Discrete lipoprotein assemblies and lipoprotein-based biomimetics offer a versatile nanoparticle platform that can be manipulated and tuned for specific medical applications. This article reviews the possibilities for constructing drug loaded, reconstituted or artificial lipoprotein particles. The advantages and limitations of lipoproteinbased delivery systems are critically evaluated and potential future challenges, especially concerning targeting specificity, concepts for lipoprotein rerouting and design of innovative lipoprotein mimetic particles using apolipoprotein sequences as targeting moieties are discussed. Finally, the review highlights potential medical applications for lipoprotein-based nanoparticle systems in the fields of cardiovascular research, cancer therapy, gene delivery and brain targeting focusing on representative examples from literature.
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Affiliation(s)
| | | | | | - Ruth Prassl
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21/6, A-8010 Graz, Austria.
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80
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Larsen AN, Sørensen KK, Johansen NT, Martel A, Kirkensgaard JJK, Jensen KJ, Arleth L, Midtgaard SR. Dimeric peptides with three different linkers self-assemble with phospholipids to form peptide nanodiscs that stabilize membrane proteins. SOFT MATTER 2016; 12:5937-5949. [PMID: 27306692 DOI: 10.1039/c6sm00495d] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Three dimers of the amphipathic α-helical peptide 18A have been synthesized with different interhelical linkers inserted between the two copies of 18A. The dimeric peptides were denoted 'beltides' where Beltide-1 refers to the 18A-dimer without a linker, Beltide-2 is the 18A-dimer with proline (Pro) as a linker and Beltide-3 is the 18A-dimer linked by two glycines (Gly-Gly). The self-assembly of the beltides with the phospholipid DMPC was studied with and without the incorporated membrane protein bacteriorhodopsin (bR) through a combination of coarse-grained MD simulations, size-exclusion chromatography (SEC), circular dichroism (CD) spectroscopy, small-angle scattering (SAS), static light scattering (SLS) and UV-Vis spectroscopy. For all three beltides, MD and combined small-angle X-ray and -neutron scattering were consistent with a disc structure composed by a phospholipid bilayer surrounded by a belt of peptides and with a total disc diameter of approximately 10 nm. CD confirmed that all three beltides were α-helical in the free form and with DMPC. However, as shown by SEC the different interhelical linkers clearly led to different properties of the beltides. Beltide-3, with the Gly-Gly linker, was very adaptable such that peptide nanodiscs could be formed for a broad range of different peptide to lipid stoichiometries and therefore also possible disc-sizes. On the other hand, both Beltide-2 with the Pro linker and Beltide-1 without a linker were less adaptable and would only form discs of certain peptide to lipid stoichiometries. SLS revealed that the structural stability of the formed peptide nanodiscs was also highly affected by the linkers and it was found that Beltide-1 gave more stable discs than the other two beltides. With respect to membrane protein stabilization, each of the three beltides in combination with DMPC stabilizes the seven-helix transmembrane protein bacteriorhodopsin significantly better than the detergent octyl glucoside, but no significant difference was observed between the three beltides. We conclude that adaptability, size, and structural stability can be tuned by changing the interhelical linker while maintaining the properties of the discs with respect to membrane protein stabilization.
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Affiliation(s)
| | | | | | | | | | - Knud J Jensen
- Department of Chemistry, University of Copenhagen, Denmark
| | - Lise Arleth
- Niels Bohr Institute, University of Copenhagen, Denmark.
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81
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Chistiakov DA, Orekhov AN, Bobryshev YV. ApoA1 and ApoA1-specific self-antibodies in cardiovascular disease. J Transl Med 2016; 96:708-18. [PMID: 27183204 DOI: 10.1038/labinvest.2016.56] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 03/21/2016] [Accepted: 04/03/2016] [Indexed: 12/15/2022] Open
Abstract
Apolipoprotein A1 (ApoA1) is a main protein moiety in high-density lipoprotein (HDL) particles. Generally, ApoA1 and HDL are considered as atheroprotective. In prooxidant and inflammatory microenvironment in the vicinity to the atherosclerotic lesion, ApoA1/HDL are subjected to modification. The chemical modifications such as oxidation, nitration, etc result in altering native architecture of ApoA1 toward dysfunctionality and abnormality. Neutrophil myeloperoxidase has a prominent role in this mechanism. Neo-epitopes could be formed and then exposed that makes them immunogenic. Indeed, these epitopes may be recognized by immune cells and induce production of proatherogenic ApoA1-specific IgG antibodies. These antibodies are biologically relevant because they are able to react with Toll-like receptor (TLR)-2 and TLR4 in target cells and induce a variety of pro-inflammatory responses. Epidemiological and functional studies underline a prognostic value of ApoA1 self-antibodies for several cardiovascular diseases, including myocardial infarction, acute coronary syndrome, and severe carotid stenosis.
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Affiliation(s)
- Dimitry A Chistiakov
- Department of Molecular Genetic Diagnostics and Cell Biology, Division of Laboratory Medicine, Institute of Pediatrics, Research Center for Children's Health, Moscow, Russia
| | - Alexander N Orekhov
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, Moscow, Russia.,Faculty of Biology, Department of Biophysics, Lomonosov Moscow State University, Moscow, Russia
| | - Yuri V Bobryshev
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, Moscow, Russia.,Faculty of Medicine, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,School of Medicine, University of Western Sydney, Campbelltown, NSW, Australia
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82
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Dwivedi P, Rodriguez J, Ibe NU, Weers PMM. Deletion of the N- or C-Terminal Helix of Apolipophorin III To Create a Four-Helix Bundle Protein. Biochemistry 2016; 55:3607-15. [PMID: 27280697 DOI: 10.1021/acs.biochem.6b00381] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Apolipophorin III (apoLp-III) is an exchangeable apolipoprotein found in insects and plays an important function in lipid transport. The protein has an unusual five-helix bundle architecture, deviating from the common four-helix bundle motif. To understand the role of the additional helix in apoLp-III, the N-terminal or C-terminal helix was deleted to create a putative four-helix bundle protein. While the protein lacking helix-1 could be expressed in bacteria albeit at reduced yields, apoLp-III lacking helix-5 could not be produced. Mutational analysis by truncating helix-5 showed that a minimum segment of approximately one-third of the C-terminal helix is required for protein expression. The variant lacking helix-5 was produced by inserting a methionine residue between helix-4 and -5; subsequent cyanogenbromide cleavage generated the four-helix variant. Both N- and C-terminal helix deletion variants displayed significantly reduced helical content, protein stability, and tertiary structure. Despite the significantly altered structure, the variants were still fully functional. The rate of dimyristoylphosphatidylcholine vesicle solubilization was enhanced 4-5-fold compared to the wild-type protein, and the deletion variants were effective in binding to lipolyzed low density lipoprotein thereby preventing lipoprotein aggregation. These results show that the additional helix of apoLp-III is not essential for lipid binding but is required for proper folding to keep the protein into a stable conformation.
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Affiliation(s)
- Pankaj Dwivedi
- Department of Chemistry and Biochemistry, California State University , Long Beach, California 90840, United States
| | - Johana Rodriguez
- Department of Chemistry and Biochemistry, California State University , Long Beach, California 90840, United States
| | - Nnejiuwa U Ibe
- Department of Chemistry and Biochemistry, California State University , Long Beach, California 90840, United States
| | - Paul M M Weers
- Department of Chemistry and Biochemistry, California State University , Long Beach, California 90840, United States
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83
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Mei X, Liu M, Herscovitz H, Atkinson D. Probing the C-terminal domain of lipid-free apoA-I demonstrates the vital role of the H10B sequence repeat in HDL formation. J Lipid Res 2016; 57:1507-17. [PMID: 27317763 DOI: 10.1194/jlr.m068874] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Indexed: 12/23/2022] Open
Abstract
apoA-I plays important structural and functional roles in reverse cholesterol transport. We have described the molecular structure of the N-terminal domain, Δ(185-243) by X-ray crystallography. To understand the role of the C-terminal domain, constructs with sequential elongation of Δ(185-243), by increments of 11-residue sequence repeats were studied and compared with Δ(185-243) and WT apoA-I. Constructs up to residue 230 showed progressively decreased percent α-helix with similar numbers of helical residues, similar detergent and lipid binding affinity, and exposed hydrophobic surface. These observations suggest that the C-terminal domain is unstructured with the exception of the last 11-residue repeat (H10B). Similar monomer-dimer equilibrium suggests that the H10B region is responsible for nonspecific aggregation. Cholesterol efflux progressively increased with elongation up to ∼60% of full-length apoA-I in the absence of the H10B. In summary, the sequential repeats in the C-terminal domain are probably unstructured with the exception of H10B. This segment appears to be responsible for initiation of lipid binding and aggregation, as well as cholesterol efflux, and thus plays a vital role during HDL formation. Based on these observations and the Δ(185-243) crystal structure, we propose a lipid-free apoA-I structural model in solution and update the mechanism of HDL biogenesis.
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Affiliation(s)
- Xiaohu Mei
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
| | - Minjing Liu
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
| | - Haya Herscovitz
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
| | - David Atkinson
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
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84
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Thermal protein unfolding by differential scanning calorimetry and circular dichroism spectroscopy Two-state model versus sequential unfolding. Q Rev Biophys 2016; 49:e9. [PMID: 27658613 DOI: 10.1017/s0033583516000044] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Thermally-induced protein unfolding is commonly described with the two-state model. This model assumes only two types of protein molecules in solution, the native (N) and the denatured, unfolded (U) protein. In reality, protein unfolding is a multistep process, even if intermediate states are only sparsely populated. As an alternative approach we explore the Zimm-Bragg theory, originally developed for the α-helix-to-random coil transition of synthetic polypeptides. The theory includes intermediate structures with concentrations determined by the cooperativity of the unfolding reaction. We illustrate the differences between the two-state model and the Zimm-Bragg theory with measurements of apolipoprotein A-1 and lysozyme by differential scanning calorimetry (DSC) and CD spectroscopy. Nine further protein examples are taken from the literature. The Zimm-Bragg theory provides a perfect fit of the calorimetric unfolding transitions for all proteins investigated. In contrast, the transition curves and enthalpies predicted by the two-state model differ considerably from the experimental results. Apolipoprotein A-1 is ~50% α-helical at ambient temperature and its unfolding follows the classical α-helix-to-random coil equilibrium. The unfolding of proteins with little α-helix content, such as lysozyme, can also be analyzed with the Zimm-Bragg theory by introducing the concept of 'folded' and 'unfolded' peptide units assuming an average unfolding enthalpy per peptide unit. DSC is the method of choice to measure the unfolding enthalpy, , but CD spectroscopy in combination with the two-state model is often used to deduce the unfolding enthalpy. This can lead to erroneous result. Not only are different enthalpies required to describe the CD and DSC transition curves but these values deviate distinctly from the experimental result. In contrast, the Zimm-Bragg theory predicts the DSC and CD unfolding transitions with the same set of parameters.
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85
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Midtgaard SR, Pedersen MC, Arleth L. Small-angle X-ray scattering of the cholesterol incorporation into human ApoA1-POPC discoidal particles. Biophys J 2016. [PMID: 26200866 DOI: 10.1016/j.bpj.2015.06.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Structural and functional aspects of high-density lipoproteins have been studied for over half a century. Due to the plasticity of this highly complex system, new aspects continue to be discovered. Here, we present a structural study of the human Apolipoprotein A1 (ApoA1) and investigate the role of its N-terminal domain, the so-called globular domain of ApoA1, in discoidal complexes with phospholipids and increasing amounts of cholesterol. Using a combination of solution-based small-angle x-ray scattering (SAXS) and molecular constrained data modeling, we show that the ApoA1-1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)-based particles are disk shaped with an elliptical cross section and composed by a central lipid bilayer surrounded by two stabilizing ApoA1 proteins. This structure is very similar to the particles formed in the so-called nanodisc system, which is based on N-terminal truncated ApoA1 protein. Although it is commonly agreed that the nanodisc is plain disk shaped, several more advanced structures have been proposed for the full-length ApoA1 in combination with POPC and cholesterol. This prompted us to make a detailed comparative study of the ApoA1 and nanodisc systems upon cholesterol uptake. Based on the presented SAXS analysis it is found that the N-terminal domains of ApoA1-POPC-cholesterol particles are not globular but instead an integrated part of the protein belt stabilizing the particles. Upon incorporation of increasing amounts of cholesterol, the presence of the N-terminal domain allows the bilayer thickness to increase while maintaining an overall flat bilayer structure. This is contrasted by the energetically more strained and less favorable lens shape required to fit the SAXS data from the N-terminal truncated nanodisc system upon cholesterol incorporation. This suggests that the N-terminal domain of ApoA1 actively participates in the stabilization of the ApoA1-POPC-cholesterol discoidal particle and allows for a more optimal lipid packing upon cholesterol uptake.
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Affiliation(s)
- Søren Roi Midtgaard
- X-Ray and Neutron Science, Niels Bohr Institute, University of Copenhagen, Denmark.
| | | | - Lise Arleth
- X-Ray and Neutron Science, Niels Bohr Institute, University of Copenhagen, Denmark
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86
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Vernet E, Popa G, Pozdnyakova I, Rasmussen JE, Grohganz H, Giehm L, Jensen MH, Wang H, Plesner B, Nielsen HM, Jensen KJ, Berthelsen J, Sundström M, van de Weert M. Large-Scale Biophysical Evaluation of Protein PEGylation Effects: In Vitro Properties of 61 Protein Entities. Mol Pharm 2016; 13:1587-98. [DOI: 10.1021/acs.molpharmaceut.6b00049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Erik Vernet
- Novo Nordisk A/S, 2880 Bagsværd, Denmark
- The
Novo Nordisk Foundation Center for Protein Research (NNF CPR), Faculty
of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gina Popa
- The
Novo Nordisk Foundation Center for Protein Research (NNF CPR), Faculty
of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Irina Pozdnyakova
- The
Novo Nordisk Foundation Center for Protein Research (NNF CPR), Faculty
of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jakob E. Rasmussen
- Department
of Chemistry, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Holger Grohganz
- Department
of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lise Giehm
- Department
of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Malene H. Jensen
- Department
of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Huabing Wang
- Department
of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bitten Plesner
- Department
of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hanne M. Nielsen
- Department
of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Knud J. Jensen
- Department
of Chemistry, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jens Berthelsen
- Costerton
Biofilm center, Department for Immunology and Microbiology, Faculty
of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Sundström
- The
Novo Nordisk Foundation Center for Protein Research (NNF CPR), Faculty
of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marco van de Weert
- Department
of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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87
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Fukuhara T, Ono C, Puig-Basagoiti F, Matsuura Y. Roles of Lipoproteins and Apolipoproteins in Particle Formation of Hepatitis C Virus. Trends Microbiol 2016; 23:618-629. [PMID: 26433694 DOI: 10.1016/j.tim.2015.07.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 07/07/2015] [Accepted: 07/20/2015] [Indexed: 02/06/2023]
Abstract
More than 160 million people worldwide are infected with hepatitis C virus (HCV), and cirrhosis and hepatocellular carcinoma induced by HCV infection are life-threatening diseases. HCV takes advantage of many aspects of lipid metabolism for an efficient propagation in hepatocytes. Due to the morphological and physiological similarities of HCV particles to lipoproteins, lipid-associated HCV particles are named lipoviroparticles. Recent analyses have revealed that exchangeable apolipoproteins directly interact with the viral membrane to generate infectious HCV particles. In this review, we summarize the roles of lipid metabolism in the life cycle of HCV.
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Affiliation(s)
- Takasuke Fukuhara
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Chikako Ono
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Francesc Puig-Basagoiti
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Yoshiharu Matsuura
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
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88
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Insights into the interaction of the N-terminal amyloidogenic polypeptide of ApoA-I with model cellular membranes. Biochim Biophys Acta Gen Subj 2016; 1860:795-801. [DOI: 10.1016/j.bbagen.2016.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 12/27/2015] [Accepted: 01/06/2016] [Indexed: 01/23/2023]
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89
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Pan L, Segrest JP. Computational studies of plasma lipoprotein lipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2401-2420. [PMID: 26969087 DOI: 10.1016/j.bbamem.2016.03.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 12/27/2022]
Abstract
Plasma lipoproteins are macromolecular assemblies of proteins and lipids found in the blood. The lipid components of lipoproteins are amphipathic lipids such as phospholipids (PLs), and unesterified cholesterols (UCs) and hydrophobic lipids such as cholesteryl esters (CEs) and triglycerides (TGs). Since lipoproteins are soft matter supramolecular assemblies easily deformable by thermal fluctuations and they also exist in varying densities and protein/lipid components, a detailed understanding of their structure/function is experimentally difficult. Molecular dynamics (MD) simulation has emerged as a particularly promising way to explore the structure and dynamics of lipoproteins. The purpose of this review is to survey the current status of computational studies of the lipid components of the lipoproteins. Computational studies aim to explore three levels of complexity for the 3-dimensional structural dynamics of lipoproteins at various metabolic stages: (i) lipoprotein particles consist of protein with minimal lipid; (ii) lipoprotein particles consist of PL-rich discoidal bilayer-like lipid particles; (iii) mature circulating lipoprotein particles consist of CE-rich or TG-rich spheroidal lipid-droplet-like particles. Due to energy barriers involved in conversion between these species, other biomolecules also participate in lipoprotein biological assembly. For example: (i) lipid-poor apolipoprotein A-I (apoA-I) interacts with ATP-binding cassette transporter A1 (ABCA1) to produce nascent discoidal high density lipoprotein (dHDL) particles; (ii) lecithin-cholesterol acyltransferase (LCAT) mediates the conversion of UC to CE in dHDL, driving spheroidal HDL (sHDL) formation; (iii) transfer proteins, cholesterol ester transfer protein (CETP) and phospholipid transfer protein (PLTP), transfer both CE and TG and PL, respectively, between lipoprotein particles. Computational studies have the potential to explore different lipoprotein particles at each metabolic stage in atomistic detail. This review discusses the current status of computational methods including all-atom MD (AAMD), coarse-grain MD (CGMD), and MD-simulated annealing (MDSA) and their applications in lipoprotein structural dynamics and biological assemblies. Results from MD simulations are discussed and compared across studies in order to identify key findings, controversies, issues and future directions. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg.
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Affiliation(s)
- Lurong Pan
- Division of Gerontology, Geriatrics, & Palliative Care, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Jere P Segrest
- Division of Gerontology, Geriatrics, & Palliative Care, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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90
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Frame NM, Gursky O. Structure of serum amyloid A suggests a mechanism for selective lipoprotein binding and functions: SAA as a hub in macromolecular interaction networks. FEBS Lett 2016; 590:866-79. [PMID: 26918388 DOI: 10.1002/1873-3468.12116] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/19/2016] [Accepted: 02/19/2016] [Indexed: 01/19/2023]
Abstract
Serum amyloid A is a major acute-phase plasma protein that modulates innate immunity and cholesterol homeostasis. We combine sequence analysis with x-ray crystal structures to postulate that SAA acts as an intrinsically disordered hub mediating interactions among proteins, lipids and proteoglycans. A structural model of lipoprotein-bound SAA monomer is proposed wherein two α-helices from the N-domain form a concave hydrophobic surface that binds lipoproteins. A C-domain, connected to the N-domain via a flexible linker, binds polar/charged ligands including cell receptors, bridging them with lipoproteins and rerouting cholesterol transport. Our model is supported by the SAA cleavage in the interdomain linker to generate the 1-76 fragment deposited in reactive amyloidosis. This model sheds new light on functions of this enigmatic protein.
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Affiliation(s)
- Nicholas M Frame
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA, USA
| | - Olga Gursky
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA, USA
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91
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Schönfeld HJ, Roessner D, Seelig J. Self-Association of Apo A-1 Studied with Dynamic and Static Light Scattering. J Phys Chem B 2016; 120:1228-35. [DOI: 10.1021/acs.jpcb.5b12397] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | - Dierk Roessner
- Wyatt Technology Europe GmbH, Hochstraße 12a, DE-56307 Dernbach, Germany
| | - Joachim Seelig
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
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92
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Protein conformational perturbations in hereditary amyloidosis: Differential impact of single point mutations in ApoAI amyloidogenic variants. Biochim Biophys Acta Gen Subj 2016; 1860:434-44. [DOI: 10.1016/j.bbagen.2015.10.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/15/2015] [Accepted: 10/23/2015] [Indexed: 12/31/2022]
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93
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Gogonea V. Structural Insights into High Density Lipoprotein: Old Models and New Facts. Front Pharmacol 2016; 6:318. [PMID: 26793109 PMCID: PMC4709926 DOI: 10.3389/fphar.2015.00318] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 12/22/2015] [Indexed: 11/13/2022] Open
Abstract
The physiological link between circulating high density lipoprotein (HDL) levels and cardiovascular disease is well-documented, albeit its intricacies are not well-understood. An improved appreciation of HDL function and overall role in vascular health and disease requires at its foundation a better understanding of the lipoprotein's molecular structure, its formation, and its process of maturation through interactions with various plasma enzymes and cell receptors that intervene along the pathway of reverse cholesterol transport. This review focuses on summarizing recent developments in the field of lipid free apoA-I and HDL structure, with emphasis on new insights revealed by newly published nascent and spherical HDL models constructed by combining low resolution structures obtained from small angle neutron scattering (SANS) with contrast variation and geometrical constraints derived from hydrogen-deuterium exchange (HDX), crosslinking mass spectrometry, electron microscopy, Förster resonance energy transfer, and electron spin resonance. Recently published low resolution structures of nascent and spherical HDL obtained from SANS with contrast variation and isotopic labeling of apolipoprotein A-I (apoA-I) will be critically reviewed and discussed in terms of how they accommodate existing biophysical structural data from alternative approaches. The new low resolution structures revealed and also provided some answers to long standing questions concerning lipid organization and particle maturation of lipoproteins. The review will discuss the merits of newly proposed SANS based all atom models for nascent and spherical HDL, and compare them with accepted models. Finally, naturally occurring and bioengineered mutations in apoA-I, and their impact on HDL phenotype, are reviewed and discuss together with new therapeutics employed for restoring HDL function.
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Affiliation(s)
- Valentin Gogonea
- Department of Chemistry, Cleveland State UniversityCleveland, OH, USA; Departments of Cellular and Molecular Medicine and the Center for Cardiovascular Diagnostics and Prevention, Cleveland ClinicCleveland, OH, USA
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94
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Melchior JT, Walker RG, Morris J, Jones MK, Segrest JP, Lima DB, Carvalho PC, Gozzo FC, Castleberry M, Thompson TB, Davidson WS. An Evaluation of the Crystal Structure of C-terminal Truncated Apolipoprotein A-I in Solution Reveals Structural Dynamics Related to Lipid Binding. J Biol Chem 2016; 291:5439-51. [PMID: 26755744 DOI: 10.1074/jbc.m115.706093] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein (apo) A-I mediates many of the anti-atherogenic functions attributed to high density lipoprotein. Unfortunately, efforts toward a high resolution structure of full-length apoA-I have not been fruitful, although there have been successes with deletion mutants. Recently, a C-terminal truncation (apoA-I(Δ185-243)) was crystallized as a dimer. The structure showed two helical bundles connected by a long, curved pair of swapped helical domains. To compare this structure to that existing under solution conditions, we applied small angle x-ray scattering and isotope-assisted chemical cross-linking to apoA-I(Δ185-243) in its dimeric and monomeric forms. For the dimer, we found evidence for the shared domains and aspects of the N-terminal bundles, but not the molecular curvature seen in the crystal. We also found that the N-terminal bundles equilibrate between open and closed states. Interestingly, this movement is one of the transitions proposed during lipid binding. The monomer was consistent with a model in which the long shared helix doubles back onto the helical bundle. Combined with the crystal structure, these data offer an important starting point to understand the molecular details of high density lipoprotein biogenesis.
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Affiliation(s)
- John T Melchior
- From the Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45237
| | - Ryan G Walker
- the Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio 45237
| | - Jamie Morris
- From the Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45237
| | - Martin K Jones
- the Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Jere P Segrest
- the Department of Medicine and Atherosclerosis Research Unit, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Diogo B Lima
- the Laboratory for Proteomics and Protein Engineering, Carlos Chagas Institute, Fiocruz, Paraná, Brazil 81350-010, and
| | - Paulo C Carvalho
- the Laboratory for Proteomics and Protein Engineering, Carlos Chagas Institute, Fiocruz, Paraná, Brazil 81350-010, and
| | - Fábio C Gozzo
- the Dalton Mass Spectrometry Laboratory, University of Campinas, São Paulo 13083-970, Brazil
| | - Mark Castleberry
- the Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio 45237
| | - Thomas B Thompson
- the Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio 45237,
| | - W Sean Davidson
- From the Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45237,
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Nakajima H, Nishitsuji K, Kawashima H, Kuwabara K, Mikawa S, Uchimura K, Akaji K, Kashiwada Y, Kobayashi N, Saito H, Sakashita N. The polyphenol (-)-epigallocatechin-3-gallate prevents apoA-IIowa amyloidosis in vitro and protects human embryonic kidney 293 cells against amyloid cytotoxicity. Amyloid 2016; 23:17-25. [PMID: 26701221 DOI: 10.3109/13506129.2015.1113167] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Apolipoprotein A-I (apoA-I) amyloidosis is either a non-hereditary form with deposits of wild-type apoA-I proteins in atherosclerotic plaques or a hereditary form with progressive accumulation of mutant apoA-I proteins in different tissues. Several small polyphenolic molecules reportedly inhibited formation of fibrillar assemblies of some amyloidogenic proteins and their cytotoxicity, but small molecules that inhibit apoA-I fibril formation have never been reported. METHODS Our methods included a thioflavin-T-binding assay, atomic force microscopy and dot blot and cell-based assays. RESULTS We showed that (-)-epigallocatechin-3-gallate (EGCG), a tea-derived flavanol, inhibited in vitro fibril formation and disaggregated fibrils preformed by the N-terminal 1-83 fragments of wild-type (WT) apoA-I and the G26R point mutation of apoA-I (apoA-IIowa). We eliminated a common structure recognized by the anti-amyloid antibody OC by incubating apoA-IIowa with EGCG or treating apoA-IIowa fibrils with EGCG, which supported the above observation. In addition, EGCG rescued human embryonic kidney 293 cells from cytotoxicity and attenuated production of reactive oxygen species, which were induced by apoA-IIowa fibrils. CONCLUSIONS Our results support the concept that EGCG inhibits amyloid fibril formation of various amyloidogenic proteins. Thus, EGCG may be a candidate for providing a structure to develop de novo inhibitors for amyloidosis treatment.
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Affiliation(s)
- Hiroyuki Nakajima
- a Department of Molecular Pathology , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan .,b Department of Molecular Physical Pharmaceutics , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan
| | - Kazuchika Nishitsuji
- a Department of Molecular Pathology , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan
| | - Hiroyuki Kawashima
- c Department of Medicinal Chemistry , Kyoto Pharmaceutical University , Yamashina-ku, Kyoto , Japan
| | - Kaori Kuwabara
- a Department of Molecular Pathology , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan .,b Department of Molecular Physical Pharmaceutics , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan
| | - Shiho Mikawa
- b Department of Molecular Physical Pharmaceutics , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan
| | - Kenji Uchimura
- d Department of Biochemistry , Nagoya University Graduate School of Medicine , Showa-ku, Nagoya , Japan
| | - Kenichi Akaji
- c Department of Medicinal Chemistry , Kyoto Pharmaceutical University , Yamashina-ku, Kyoto , Japan
| | - Yoshiki Kashiwada
- e Department of Pharmacognosy , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan , and
| | - Norihiro Kobayashi
- f Department of Bioanalytical Chemistry , Kobe Pharmaceutical University , Higashinada-ku, Kobe , Japan
| | - Hiroyuki Saito
- b Department of Molecular Physical Pharmaceutics , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan
| | - Naomi Sakashita
- a Department of Molecular Pathology , Institute of Biomedical Sciences, Tokushima University Graduate School , Tokushima , Japan
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96
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Dalla-Riva J, Lagerstedt JO, Petrlova J. Structural and Functional Analysis of the ApolipoproteinA-I A164S Variant. PLoS One 2015; 10:e0143915. [PMID: 26605794 PMCID: PMC4659549 DOI: 10.1371/journal.pone.0143915] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 11/11/2015] [Indexed: 01/15/2023] Open
Abstract
Apolipoprotein A-I (apoA-I) is the main protein involved in the formation of high-density lipoprotein (HDL), it is the principal mediator of the reverse cholesterol transfer (RCT) pathway and provides cardio-protection. In addition to functional wild-type apoA-I, several variants have been shown to associate with hereditary amyloidosis. In this study we have performed biophysical and biochemical analyses of the structure and functional properties of the A164S variant of apoA-I (1:500 in the Danish general population), which is the first known mutation of apoA-I that leads to an increased risk of ischaemic heart disease (IHD), myocardial infarction and mortality without associated low HDL cholesterol levels. Despite the fact that epidemiologically IHD is associated with low plasma levels of HDL, the A164S mutation is linked to normal plasma levels of lipids, HDL and apoA-I, suggesting impaired functionality of this variant. Using biophysical techniques (e.g., circular dichroism spectroscopy and electron microscopy) to determine secondary structure, stability and pro-amyloidogenic property of the lipid free A164S apoA-I variant, our observations suggest similarity in structural properties between apoA-I WT and apoA-I A164S. However, the A164S apoA-I variant exhibits lower binding affinity to lipids but forms similar sized HDL particles to those produced by WT.
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Affiliation(s)
| | - Jens O. Lagerstedt
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- * E-mail:
| | - Jitka Petrlova
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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97
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Das M, Wilson CJ, Mei X, Wales TE, Engen JR, Gursky O. Structural Stability and Local Dynamics in Disease-Causing Mutants of Human Apolipoprotein A-I: What Makes the Protein Amyloidogenic? J Mol Biol 2015; 428:449-62. [PMID: 26562506 DOI: 10.1016/j.jmb.2015.10.029] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 10/26/2015] [Accepted: 10/27/2015] [Indexed: 01/27/2023]
Abstract
ApoA-I, the major protein of plasma high-density lipoprotein, removes cellular cholesterol and protects against atherosclerosis. ApoA-I mutations can cause familial amyloidosis, a life-threatening disease wherein N-terminal protein fragments form fibrils in vital organs. To unveil the protein misfolding mechanism and to understand why some mutations cause amyloidosis while others do not, we analyzed the structure, stability, and lipid-binding properties of naturally occurring mutants of full-length human apoA-I causing either amyloidosis (G26R, W50R, F71Y, and L170P) or aberrant lipid metabolism (L159R). Global and local protein conformation and dynamics in solution were assessed by circular dichroism, fluorescence, and hydrogen-deuterium exchange mass spectrometry. All mutants showed increased deuteration in residues 14-22, supporting our hypothesis that decreased protection of this major amyloid "hot spot" can trigger protein misfolding. In addition, L159R showed local helical unfolding near the mutation site, consistent with cleavage of this mutant in plasma to generate the labile 1-159 fragment. Together, the results suggest that reduced protection of the major amyloid "hot spot", combined with the structural integrity of the native helix bundle conformation, shifts the balance from protein clearance to β-aggregation. A delicate balance between the overall structural integrity of a globular protein and the local destabilization of its amyloidogenic segments may be a fundamental determinant of this and other amyloid diseases. Furthermore, mutation-induced conformational changes observed in the helix bundle, which comprises the N-terminal 75% of apoA-I, and its flexible C-terminal tail suggest the propagation of structural perturbations to distant sites via an unexpected template-induced ensemble-based mechanism, challenging the classical structure-based view.
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Affiliation(s)
- Madhurima Das
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA
| | - Christopher J Wilson
- Department of Chemistry & Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Xiaohu Mei
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA
| | - Thomas E Wales
- Department of Chemistry & Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
| | - John R Engen
- Department of Chemistry & Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Olga Gursky
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA.
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98
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Tiniakou I, Kanaki Z, Georgopoulos S, Chroni A, Van Eck M, Fotakis P, Zannis VI, Kardassis D. Natural human apoA-I mutations L141R Pisa and L159R FIN alter HDL structure and functionality and promote atherosclerosis development in mice. Atherosclerosis 2015; 243:77-85. [DOI: 10.1016/j.atherosclerosis.2015.08.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 07/01/2015] [Accepted: 08/20/2015] [Indexed: 10/23/2022]
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99
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Pisciotta L, Vitali C, Favari E, Fossa P, Adorni MP, Leone D, Artom N, Fresa R, Calabresi L, Calandra S, Bertolini S. A complex phenotype in a child with familial HDL deficiency due to a novel frameshift mutation in APOA1 gene (apoA-IGuastalla). J Clin Lipidol 2015; 9:837-846. [PMID: 26687706 DOI: 10.1016/j.jacl.2015.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 08/07/2015] [Accepted: 09/09/2015] [Indexed: 01/07/2023]
Abstract
BACKGROUND We describe a kindred with high-density lipoprotein (HDL) deficiency due to APOA1 gene mutation in which comorbidities affected the phenotypic expression of the disorder. METHODS An overweight boy with hypertriglyceridemia (HTG) and HDL deficiency (HDL cholesterol 0.39 mmol/L, apoA-I 40 mg/dL) was investigated. We sequenced the candidate genes for HTG (LPL, APOC2, APOA5, GPIHBP1, LMF1) and HDL deficiency (LCAT, ABCA1 and APOA1), analyzed HDL subpopulations, measured cholesterol efflux capacity (CEC) of sera and constructed a model of the mutant apoA-I. RESULTS No mutations in HTG-related genes, ABCA1 and LCAT were found. APOA1 sequence showed that the proband, his mother and maternal grandfather were heterozygous of a novel frameshift mutation (c.546_547delGC), which generated a truncated protein (p.[L159Afs*20]) containing 177 amino acids with an abnormal C-terminal tail of 19 amino acids. Trace amounts of this protein were detectable in plasma. Mutation carriers had reduced levels of LpA-I, preβ-HDL and large HDL and no detectable HDL-2 in their plasma; their sera had a reduced CEC specifically the ABCA1-mediated CEC. Metabolic syndrome in the proband explains the extremely low HDL cholesterol level (0.31 mmol/L), which was half of that found in the other carriers. The proband's mother and grandfather, both presenting low plasma low-density lipoprotein cholesterol, were carriers of the β-thalassemic trait, a condition known to be associated with a reduced low-density lipoprotein cholesterol and a reduced prevalence of cardiovascular disease. This trait might have delayed the development of atherosclerosis related to HDL deficiency. CONCLUSIONS In these heterozygotes for apoA-I truncation, the metabolic syndrome has deleterious effect on HDL system, whereas β-thalassemia trait may delay the onset of cardiovascular disease.
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Affiliation(s)
- Livia Pisciotta
- Department of Internal Medicine, University of Genoa, Genoa, Italy
| | - Cecilia Vitali
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Elda Favari
- Department of Pharmacy, University of Parma, Parma, Italy
| | - Paola Fossa
- Department of Pharmacy, University of Genoa, Genoa, Italy
| | | | - Daniela Leone
- Laboratory of Human Genetics, Galliera Hospital, Genoa, Italy
| | - Nathan Artom
- Department of Internal Medicine, University of Genoa, Genoa, Italy
| | - Raffaele Fresa
- Department of Internal Medicine, University of Genoa, Genoa, Italy
| | - Laura Calabresi
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Sebastiano Calandra
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.
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Affiliation(s)
- Iwona Siuda
- Department of Biological
Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
| | - D. Peter Tieleman
- Department of Biological
Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
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