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Muñoz SM, Vallejos-Baccelliere G, Manubens A, Salazar ML, Nascimento AFZ, Tapia-Reyes P, Meneses C, Ambrosio ALB, Becker MI, Guixé V, Castro-Fernandez V. Structural insights into a functional unit from an immunogenic mollusk hemocyanin. Structure 2024; 32:812-823.e4. [PMID: 38513659 DOI: 10.1016/j.str.2024.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/30/2024] [Accepted: 02/23/2024] [Indexed: 03/23/2024]
Abstract
Mollusk hemocyanins, among the largest known proteins, are used as immunostimulants in biomedical and clinical applications. The hemocyanin of the Chilean gastropod Concholepas concholepas (CCH) exhibits unique properties, which makes it safe and effective for human immunotherapy, as observed in animal models of bladder cancer and melanoma, and dendritical cell vaccine trials. Despite its potential, the structure and amino acid sequence of CCH remain unknown. This study reports two sequence fragments of CCH, representing three complete functional units (FUs). We also determined the high-resolution (1.5 Å) X-ray crystal structure of an "FU-g type" from the CCHB subunit. This structure enables in-depth analysis of chemical interactions at the copper-binding center and unveils an unusual, truncated N-glycosylation pattern. These features are linked to eliciting more robust immunological responses in animals, offering insights into CCH's enhanced immunostimulatory properties and opening new avenues for its potential applications in biomedical research and therapies.
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Affiliation(s)
- Sebastián M Muñoz
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 780003, Chile
| | - Gabriel Vallejos-Baccelliere
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 780003, Chile
| | - Augusto Manubens
- Departamento de Investigación y Desarrollo, Biosonda Corp., Santiago 7750629, Chile; Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago 7750629, Chile
| | - Michelle L Salazar
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago 7750629, Chile
| | - Andrey F Z Nascimento
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Sao Paulo 13083-970, Brazil
| | - Patricio Tapia-Reyes
- Escuela de Biotecnología, Facultad de Ciencias, Universidad Santo Tomás, Santiago 8370003, Chile; Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Claudio Meneses
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile; Departamento de Fruticultura y Enología, Facultad de Agronomía y Sistemas Naturales, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile; Millennium Nucleus Development of Super Adaptable Plants (MN-SAP), Santiago 8331150, Chile; Millennium Institute Center for Genome Regulation (CRG), Santiago 8331150, Chile
| | - Andre L B Ambrosio
- Sao Carlos Institute of Physics (IFSC), University of Sao Paulo (USP), Sao Carlos, Sao Paulo 13563-120, Brazil
| | - María Inés Becker
- Departamento de Investigación y Desarrollo, Biosonda Corp., Santiago 7750629, Chile; Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago 7750629, Chile
| | - Victoria Guixé
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 780003, Chile.
| | - Victor Castro-Fernandez
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 780003, Chile.
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2
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Ji R, Guan L, Hu Z, Cheng Y, Cai M, Zhao G, Zang J. A comprehensive review on hemocyanin from marine products: Structure, functions, its implications for the food industry and beyond. Int J Biol Macromol 2024; 269:132041. [PMID: 38705315 DOI: 10.1016/j.ijbiomac.2024.132041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/07/2024]
Abstract
Hemocyanin, an oxygen-transport protein, is widely distributed in the hemolymph of marine arthropods and mollusks, playing an important role in their physiological processes. Recently, hemocyanin has been recognized as a multifunctional glycoprotein involved in the immunological responses of aquatic invertebrates. Consequently, the link between hemocyanin functions and their potential applications has garnered increased attention. This review offers an integrated overview of hemocyanin's structure, physicochemical characteristics, and bioactivities to further promote the utilization of hemocyanin derived from marine products. Specifically, we review its implication in two aspects of food and aquaculture industries: quality and health. Hemocyanin's inducible phenoloxidase activity is thought to be an inducer of melanosis in crustaceans. New anti-melanosis agents targeted to hemocyanin need to be explored. The red-color change observed in shrimp shells is related to hemocyanin, affecting consumer preferences. Hemocyanin's adaptive modification in response to the aquatic environment is available as a biomarker. Additionally, hemocyanin is endowed with bioactivities encompassing anti-microbial, antiviral, and therapeutic activities. Hemocyanin is also a novel allergen and its allergenic features remain incompletely characterized.
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Affiliation(s)
- Ruiyang Ji
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Leying Guan
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Ziyan Hu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Yishen Cheng
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Meng Cai
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Guanghua Zhao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Jiachen Zang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
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3
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Pasqualetto G, Mack A, Lewis E, Cooper R, Holland A, Borucu U, Mantell J, Davies T, Weckener M, Clare D, Green T, Kille P, Muhlhozl A, Young MT. CryoEM structure and Alphafold molecular modelling of a novel molluscan hemocyanin. PLoS One 2023; 18:e0287294. [PMID: 37347755 PMCID: PMC10286996 DOI: 10.1371/journal.pone.0287294] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/03/2023] [Indexed: 06/24/2023] Open
Abstract
Hemocyanins are multimeric oxygen transport proteins present in the blood of arthropods and molluscs, containing up to 8 oxygen-binding functional units per monomer. In molluscs, hemocyanins are assembled in decamer 'building blocks' formed of 5 dimer 'plates', routinely forming didecamer or higher-order assemblies with d5 or c5 symmetry. Here we describe the cryoEM structures of the didecamer (20-mer) and tridecamer (30-mer) forms of a novel hemocyanin from the slipper limpet Crepidula fornicata (SLH) at 7.0 and 4.7 Å resolution respectively. We show that two decamers assemble in a 'tail-tail' configuration, forming a partially capped cylinder, with an additional decamer adding on in 'head-tail' configuration to make the tridecamer. Analysis of SLH samples shows substantial heterogeneity, suggesting the presence of many higher-order multimers including tetra- and pentadecamers, formed by successive addition of decamers in head-tail configuration. Retrieval of sequence data for a full-length isoform of SLH enabled the use of Alphafold to produce a molecular model of SLH, which indicated the formation of dimer slabs with high similarity to those found in keyhole limpet hemocyanin. The fit of the molecular model to the cryoEM density was excellent, showing an overall structure where the final two functional units of the subunit (FU-g and FU-h) form the partial cap at one end of the decamer, and permitting analysis of the subunit interfaces governing the assembly of tail-tail and head-tail decamer interactions as well as potential sites for N-glycosylation. Our work contributes to the understanding of higher-order oligomer formation in molluscan hemocyanins and demonstrates the utility of Alphafold for building accurate structural models of large oligomeric proteins.
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Affiliation(s)
- Gaia Pasqualetto
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Andrew Mack
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Emily Lewis
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Ryan Cooper
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Alistair Holland
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Ufuk Borucu
- Faculty of Life Sciences, GW4 Facility for High-Resolution Electron Cryo-Microscopy, Wolfson Bioimaging Facility, University of Bristol, Bristol, United Kingdom
| | - Judith Mantell
- Faculty of Life Sciences, GW4 Facility for High-Resolution Electron Cryo-Microscopy, Wolfson Bioimaging Facility, University of Bristol, Bristol, United Kingdom
| | - Tom Davies
- School of Chemistry, Cardiff University, Cardiff, United Kingdom
| | - Miriam Weckener
- The Rosalind Franklin Institute, Structural Biology, Harwell Science Campus, Didcot, United Kingdom
| | - Dan Clare
- Electron Bioimaging Centre, Diamond Light Source, Harwell, United Kingdom
| | - Tom Green
- Advanced Research Computing at Cardiff, Cardiff University, Cardiff, United Kingdom
| | - Pete Kille
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | - Mark T. Young
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
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Schäfer GG, Grebe LJ, Schinkel R, Lieb B. The Evolution of Hemocyanin Genes in Caenogastropoda: Gene Duplications and Intron Accumulation in Highly Diverse Gastropods. J Mol Evol 2021; 89:639-655. [PMID: 34757470 PMCID: PMC8599328 DOI: 10.1007/s00239-021-10036-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 10/15/2021] [Indexed: 11/30/2022]
Abstract
Hemocyanin is the oxygen transport protein of most molluscs and represents an important physiological factor that has to be well-adapted to their environments because of the strong influences of abiotic factors on its oxygen affinity. Multiple independent gene duplications and intron gains have been reported for hemocyanin genes of Tectipleura (Heterobranchia) and the caenogastropod species Pomacea canaliculata, which contrast with the uniform gene architectures of hemocyanins in Vetigastropoda. The goal of this study was to analyze hemocyanin gene evolution within the diverse group of Caenogastropoda in more detail. Our findings reveal multiple gene duplications and intron gains and imply that these represent general features of Apogastropoda hemocyanins. Whereas hemocyanin exon–intron structures are identical within different Tectipleura lineages, they differ strongly within Caenogastropoda among phylogenetic groups as well as between paralogous hemocyanin genes of the same species. Thus, intron accumulation took place more gradually within Caenogastropoda but finally led to a similar consequence, namely, a multitude of introns. Since both phenomena occurred independently within Heterobranchia and Caenogastropoda, the results support the hypothesis that introns may contribute to adaptive radiation by offering new opportunities for genetic variability (multiple paralogs that may evolve differently) and regulation (multiple introns). Our study indicates that adaptation of hemocyanin genes may be one of several factors that contributed to the evolution of the large diversity of Apogastropoda. While questions remain, this hypothesis is presented as a starting point for the further study of hemocyanin genes and possible correlations between hemocyanin diversity and adaptive radiation.
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Affiliation(s)
- Gabriela Giannina Schäfer
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Lukas Jörg Grebe
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Robin Schinkel
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Bernhard Lieb
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany.
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5
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Schäfer GG, Grebe LJ, Depoix F, Lieb B. Hemocyanins of Muricidae: New 'Insights' Unravel an Additional Highly Hydrophilic 800 kDa Mass Within the Molecule. J Mol Evol 2021; 89:62-72. [PMID: 33439299 PMCID: PMC7884596 DOI: 10.1007/s00239-020-09986-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/17/2020] [Indexed: 02/03/2023]
Abstract
Hemocyanins are giant oxygen transport proteins that freely float within the hemolymph of most molluscs. The basic quaternary structure of molluscan hemocyanins is a cylindrical decamer with a diameter of 35 nm which is built of 400 kDa subunits. Previously published results, however, showed that one out of two hemocyanin subunits of Rapana venosa encompasses two polypeptides, one 300 kDa and one 100 kDa polypeptide which aggregate to typical 4 MDa and 8 MDa hemocyanin (di-)decamer molecules. It was shown that the polypeptides are bound most probably by one or more cysteine disulfide bridges but it remained open if these polypeptides were coded by one or two genes. Our here presented results clearly showed that both polypeptides are coded by one gene only and that this phenomenon can also be found in the gastropod Nucella lapillus. Thus, it can be defined as clade-specific for Muricidae, a group of the very diverse Caenogastropoda. In addition, we discovered a further deviation of this hemocyanin subunit within both species, namely a region of 340 mainly hydrophilic amino acids (especially histidines and aspartic acids) which have not been identified in any other molluscan hemocyanin, yet. Our results indicate that, within the quaternary structure, these additional amino acids most probably protrude within the inner part of didecamer cylinders, forming a large extra mass of up to 800 kDa. They presumably influence the structure of the protein and may affect the functionality. Thus, these findings reveal further insights into the evolution and structures of gastropod hemocyanins.
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Affiliation(s)
- Gabriela Giannina Schäfer
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany.
| | - Lukas Jörg Grebe
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Frank Depoix
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
| | - Bernhard Lieb
- Institute of Molecular Physiology, Johannes Gutenberg-University of Mainz, Johann-Joachim-Becher-Weg 7, 55128, Mainz, Germany
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6
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Abstract
Instead of the red blood of vertebrates, most molluscs have blue hemolymph containing hemocyanin, a type-3 copper-containing protein. The hemoglobin of vertebrate blood is replaced in most molluscs with hemocyanin, which plays the role of an oxygen transporter. Oxygen-binding in hemocyanin changes its hue from colorless deoxygenated hemocyanin into blue oxygenated hemocyanin. Molecules of molluscan hemocyanin are huge, cylindrical multimeric proteins-one of the largest protein molecules in the natural world. Their huge molecular weight (from 3.3 MDa to more than 10 MDa) are the defining characteristic of molluscan hemocyanin, a property that has complicated structural analysis of the molecules for a long time. Recently, the structural analysis of a cephalopod (squid) hemocyanin has succeeded using a hybrid method employing both X-ray crystallography and cryo-EM. In a biochemical breakthrough for molluscan hemocyanin, the first quaternary structure with atomic resolution is on the verge of solving the mystery of molluscan hemocyanin. Here we describe the latest information about the molecular structure, classification and evolution of the molecule, and the physiology of molluscan hemocyanin.
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7
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Azulay H, Lutaty A, Qvit N. Approach for comparing protein structures and origami models. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183132. [PMID: 31738904 DOI: 10.1016/j.bbamem.2019.183132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/05/2019] [Accepted: 10/28/2019] [Indexed: 11/20/2022]
Abstract
The research fields of proteins and origami have intersected in the study of folding and de-novo design of proteins. However, there is limited knowledge on the analogy between protein structures and origami models. We propose a general approach for comparing protein structures with origami models, and present a test case, comparing transmembrane β-barrel and α-helical barrel with the Yoshimura and Kresling origami models. While both shapes and structures may look similar, we demonstrated that the β-barrel and the α-helical barrel are in agreement only with the shape and structural characteristics of the Kresling model. Through the analogy, it is explained how the structural characteristic can help the β-barrel and α-helical barrel to adjust length and diameter in response to changes in the membrane structure. However, such conformations only apply to the α-helical barrel, and the β-barrel, in spite of resembles to the Kresling model, remains stiff due to hydrogen bonds between the β-strands. Thus, our analysis suggests that there are similar patterns between protein structures and origami models and that the proposed approach may provide important insight on the role that the structure of a protein fulfils, and on the preferred structural design of novel proteins with unique characteristics.
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Affiliation(s)
| | | | - Nir Qvit
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Henrietta Szold St. 8, POB 1589, Safed, Israel.
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Chiumiento IR, Ituarte S, Sun J, Qiu JW, Heras H, Dreon MS. Hemocyanin of the caenogastropod Pomacea canaliculata exhibits evolutionary differences among gastropod clades. PLoS One 2020; 15:e0228325. [PMID: 31999773 PMCID: PMC6992001 DOI: 10.1371/journal.pone.0228325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/10/2020] [Indexed: 11/20/2022] Open
Abstract
Structural knowledge of gastropod hemocyanins is scarce. To better understand their evolution and diversity we studied the hemocyanin of a caenogastropod, Pomacea canaliculata (PcH). Through a proteomic and genomic approach, we identified 4 PcH subunit isoforms, in contrast with other gastropods that usually have 2 or 3. Each isoform has the typical Keyhole limpet-type hemocyanin architecture, comprising a string of eight globular functional units (FUs). Correspondingly, genes are organized in eight FUs coding regions. All FUs in the 4 genes are encoded by more than one exon, a feature not found in non- caenogastropods. Transmission electron microscopy images of PcH showed a cylindrical structure organized in di, tri and tetra-decamers with an internal collar structure, being the di and tri-decameric cylinders the most abundant ones. PcH is N-glycosylated with high mannose and hybrid-type structures, and complex-type N-linked glycans, with absence of sialic acid. Terminal β-N-GlcNAc residues and nonreducing terminal α-GalNAc are also present. The molecule lacks O-linked glycosylation but presents the T-antigen (Gal-β1,3-GalNAc). Using an anti-PcH polyclonal antibody, no cross-immunoreactivity was observed against other gastropod hemocyanins, highlighting the presence of clade-specific structural differences among gastropod hemocyanins. This is, to the best of our knowledge, the first gene structure study of a Caenogastropoda hemocyanin.
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Affiliation(s)
- Ignacio Rafael Chiumiento
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
| | - Santiago Ituarte
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
| | - Jin Sun
- Department of Ocean Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Jian Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Horacio Heras
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
- Cátedra de Química Biológica, Facultad de Ciencias Naturales y Museo, UNLP, La Plata, Argentina
| | - Marcos Sebastián Dreon
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP)–CONICET, La Plata, Argentina
- Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, UNLP, La Plata, Argentina
- * E-mail:
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Abstract
The copper-containing hemocyanins are proteins responsible for the binding, transportation and storage of dioxygen within the blood (hemolymph) of many invertebrates. Several additional functions have been attributed to both arthropod and molluscan hemocyanins, including (but not limited to) enzymatic activity (namely phenoloxidase), hormone transport, homeostasis (ecdysis) and hemostasis (clot formation). An important secondary function of hemocyanin involves aspects of innate immunity-such as acting as a precursor of broad-spectrum antimicrobial peptides and microbial/viral agglutination. In this chapter, we present the reader with an up-to-date synthesis of the known functions of hemocyanins and the structural features that facilitate such activities.
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Affiliation(s)
- Christopher J Coates
- Department of Biosciences, College of Science, Swansea University, Swansea, Wales, SA2 8PP, UK.
| | - Elisa M Costa-Paiva
- Departamento de Zoologia, Instituto Biociências, Universidade de São Paulo, São Paulo, Brazil
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Tanaka Y, Kato S, Stabrin M, Raunser S, Matsui T, Gatsogiannis C. Cryo-EM reveals the asymmetric assembly of squid hemocyanin. IUCRJ 2019; 6:426-437. [PMID: 31098023 PMCID: PMC6503924 DOI: 10.1107/s205225251900321x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/06/2019] [Indexed: 06/09/2023]
Abstract
The oxygen transporter of molluscs, hemocyanin, consists of long pearl-necklace-like subunits of several globular domains. The subunits assemble in a complex manner to form cylindrical decamers. Typically, the first six domains of each subunit assemble together to form the cylinder wall, while the C-terminal domains form a collar that fills or caps the cylinder. During evolution, various molluscs have been able to fine-tune their oxygen binding by deleting or adding C-terminal domains and adjusting their inner-collar architecture. However, squids have duplicated one of the wall domains of their subunits instead. Here, using cryo-EM and an optimized refinement protocol implemented in SPHIRE, this work tackled the symmetry-mismatched structure of squid hemocyanin, revealing the precise effect of this duplication on its quaternary structure and providing a potential model for its structural evolution.
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Affiliation(s)
- Yoshikazu Tanaka
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Japan Science and Technology Agency, PRESTO, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Sanae Kato
- Faculty of Fisheries, Kagoshima University, Kagoshima 890-0056, Japan
- The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0056, Japan
| | - Markus Stabrin
- Max Planck Institute of Molecular Physiology, Department of Structural Biochemistry, Otto Hahn Strasse 11, Dortmund 44227, Germany
| | - Stefan Raunser
- Max Planck Institute of Molecular Physiology, Department of Structural Biochemistry, Otto Hahn Strasse 11, Dortmund 44227, Germany
| | - Takashi Matsui
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Christos Gatsogiannis
- Max Planck Institute of Molecular Physiology, Department of Structural Biochemistry, Otto Hahn Strasse 11, Dortmund 44227, Germany
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11
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Dolashki A, Velkova L, Voelter W, Dolashka P. Structural and conformational stability of hemocyanin from the garden snail Cornu aspersum. ACTA ACUST UNITED AC 2019; 74:113-123. [DOI: 10.1515/znc-2018-0084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 02/02/2019] [Indexed: 11/15/2022]
Abstract
Abstract
Various aspects of biomedical applications of molluscan hemocyanins, associated with their immunogenic properties and antitumor activity, promoted us to perform structural studies on these glycoproteins. The stability and reassociation behavior of native Cornu aspersum hemocyanin (CaH) are studied in the presence of different concentrations of Ca2+ and Mg2+ ions and pH values using electron microscopy. Higher concentrations of those ions led to a more rapid reassociation of CaH, resulting in stable multidecamers with different lengths. The conformational changes of native CaH are investigated within a wide pH-temperature range by UV circular dichroism. The relatively small changes of initial [θ]λ indicated that many secondary structural elements are preserved, even at high temperatures above 80°C, especially at neutral pH. The mechanism of thermal unfolding of CaH has a complicated character, and the process is irreversible. The conformational stability of the native didecameric aggregates of CaH toward various denaturants indicates that hydrophilic and polar forces stabilize the quaternary structure. For the first time, the unfolding of native CaH in water solutions in the presence of four different denaturants is investigated. The free energy of stabilization in water, ∆GD
H2O, was calculated in the range of 15.48–16.95 kJ mol−1. The presented results will facilitate the further investigation of the properties and potential applications of CaH.
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Affiliation(s)
- Aleksandar Dolashki
- Institute of Organic Chemistry with Centre of Phytochemistry , Bulgarian Academy of Sciences , Acad. G. Bonchev str., bl.9 , Sofia 1113 , Bulgaria
| | - Lyudmila Velkova
- Institute of Organic Chemistry with Centre of Phytochemistry , Bulgarian Academy of Sciences , Acad. G. Bonchev str., bl.9 , Sofia 1113 , Bulgaria
| | - Wolfgang Voelter
- Interfacultary Institute of Biochemistry , University of Tübingen , Hoppe-Seyler-Straße 4 , D-72076 Tübingen , Germany
| | - Pavlina Dolashka
- Institute of Organic Chemistry with Centre of Phytochemistry , Bulgarian Academy of Sciences , Acad. G. Bonchev str., bl.9 , Sofia 1113 , Bulgaria
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12
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Yao T, Zhao MM, He J, Han T, Peng W, Zhang H, Wang JY, Jiang JZ. Gene expression and phenoloxidase activities of hemocyanin isoforms in response to pathogen infections in abalone Haliotis diversicolor. Int J Biol Macromol 2019; 129:538-551. [PMID: 30731165 DOI: 10.1016/j.ijbiomac.2019.02.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/02/2019] [Accepted: 02/02/2019] [Indexed: 12/13/2022]
Abstract
Hemocyanins (Hc), the main protein components of hemolymph in invertebrates, are not only involved in oxygen transport but also linked to non-specific immune responses. In this study, we used abalone (Haliotis diversicolor) Hc to study the basis of its diversified functions through gene, protein, peptides, and phenoloxidase (PO) activity levels. Three complete hemocyanin gene (HdH) sequences were cloned for the first time. By comparing the copies and location of HdH between abalone and other mollusks, we propose that Hc gene duplication and linkage is likely to be common during the evolution of mollusk respiratory proteins. We further demonstrate that all three genes could be expressed in abalone, with expression varying based on the developmental stages, tissue types, and different pathogen infections. However, HdH1 and HdH2 appear to be synthesized by the same cells by fluorescence in situ hybridization. Furthermore, the PO activity of HdH can be induced by trypsin, urea, and SDS in vitro. Viral infection can stimulate its PO activity in vivo by cleaving the protein into fragments. Consequently, we present a comprehensive study of abalone hemocyanin, providing important evidence for an in-depth understanding of the physiological and immune functions of Hc in mollusks.
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Affiliation(s)
- Tuo Yao
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China
| | - Man-Man Zhao
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China; Novoprotein Scientific Inc., Wujiang, Jiangsu 215200, PR China
| | - Jian He
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, PR China
| | - Tao Han
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China
| | - Wen Peng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China
| | - Han Zhang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China
| | - Jiang-Yong Wang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China
| | - Jing-Zhe Jiang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, PR China.
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13
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Dolashki A, Dolashka P, Stenzl A, Stevanovic S, Aicher WK, Velkova L, Velikova R, Voelter W. Antitumour activity of Helix hemocyanin against bladder carcinoma permanent cell lines. BIOTECHNOL BIOTEC EQ 2019. [DOI: 10.1080/13102818.2018.1507755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Aleksandar Dolashki
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Pavlina Dolashka
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Arnulf Stenzl
- Department of Urology, University of Tübingen Hospital, Tübingen, Germany
| | - Stefan Stevanovic
- Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany
| | - Wilhelm K. Aicher
- Department of Urology, University of Tübingen Hospital, Tübingen, Germany
| | - Lyudmila Velkova
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Radostina Velikova
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Wolfgang Voelter
- Interfacultary Institute of Biochemistry, University of Tübingen, Tübingen, Germany
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14
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Gatsogiannis C, Merino F, Roderer D, Balchin D, Schubert E, Kuhlee A, Hayer-Hartl M, Raunser S. Tc toxin activation requires unfolding and refolding of a β-propeller. Nature 2018; 563:209-213. [DOI: 10.1038/s41586-018-0556-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/23/2018] [Indexed: 12/14/2022]
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15
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Pfeifer W, Lill P, Gatsogiannis C, Saccà B. Hierarchical Assembly of DNA Filaments with Designer Elastic Properties. ACS NANO 2018; 12:44-55. [PMID: 29141133 DOI: 10.1021/acsnano.7b06012] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The elastic features of protein filaments are encoded in their component units and in the way they are connected, thus defining a biunivocal relationship between the monomer and the result of its self-assembly. Using DNA origami approaches, we constructed a reconfigurable module, composed of two quasi-independent domains and four possible interfaces, capable of facial and lateral growing through specific recognition patterns. Whereas the flexibility of the intra-domains region can be regulated by switchable DNA motifs, the inter-domain interfaces feature mutually and self-complementary shapes, whose pairwise association leads to filaments of programmable periodicity and variable persistence length. Thus, we show here that the assembly pathway leading to oligomeric chains can be finely tuned and fully controlled, enabling the emulation of protein-like filaments using a single construction principle. Our approach results in artificial materials with a large variety of ultrastructures and bending strengths comparable, or even superior, to their natural counterparts.
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Affiliation(s)
- Wolfgang Pfeifer
- Centre for Medical Biotechnology (ZMB) and Centre for Nano Integration Duisburg-Essen (CENIDE), University of Duisburg-Essen , Universitätstraße 2, 45117 Essen, Germany
| | - Pascal Lill
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology , Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Christos Gatsogiannis
- Department of Structural Biochemistry, Max-Planck-Institute of Molecular Physiology , Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Barbara Saccà
- Centre for Medical Biotechnology (ZMB) and Centre for Nano Integration Duisburg-Essen (CENIDE), University of Duisburg-Essen , Universitätstraße 2, 45117 Essen, Germany
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16
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Kato S, Matsui T, Gatsogiannis C, Tanaka Y. Molluscan hemocyanin: structure, evolution, and physiology. Biophys Rev 2017; 10:191-202. [PMID: 29235083 DOI: 10.1007/s12551-017-0349-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 11/14/2017] [Indexed: 10/18/2022] Open
Abstract
Most molluscs have blue blood because their respiratory molecule is hemocyanin, a type-3 copper-binding protein that turns blue upon oxygen binding. Molluscan hemocyanins are huge cylindrical multimeric glycoproteins that are found freely dissolved in the hemolymph. With molecular masses ranging from 3.3 to 13.5 MDa, molluscan hemocyanins are among the largest known proteins. They form decamers or multi-decamers of 330- to 550-kDa subunits comprising more than seven paralogous functional units. Based on the organization of functional domains, they assemble to form decamers, di-decamers, and tri-decamers. Their structure has been investigated using a combination of single particle electron cryo-microsopy of the entire structure and high-resolution X-ray crystallography of the functional unit, although, the one exception is squid hemocyanin for which a crystal structure analysis of the entire molecule has been carried out. In this review, we explain the molecular characteristics of molluscan hemocyanin mainly from the structural viewpoint, in which the structure of the functional unit, architecture of the huge cylindrical multimer, relationship between the composition of the functional unit and entire tertiary structure, and possible functions of the carbohydrates are introduced. We also discuss the evolutionary implications and physiological significance of molluscan hemocyanin.
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Affiliation(s)
- Sanae Kato
- Faculty of Fisheries, Kagoshima University, 4-50-20 Shimoarata, Kagoshima, 890-0056, Japan.
| | - Takashi Matsui
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Christos Gatsogiannis
- Department of Structural Biochemistry, Max Planck Institute Molecular Physiology, 44227, Dortmund, Germany
| | - Yoshikazu Tanaka
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan. .,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Sendai, 980-8577, Japan.
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17
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Pizarro-Bauerle J, Maldonado I, Sosoniuk-Roche E, Vallejos G, López MN, Salazar-Onfray F, Aguilar-Guzmán L, Valck C, Ferreira A, Becker MI. Molluskan Hemocyanins Activate the Classical Pathway of the Human Complement System through Natural Antibodies. Front Immunol 2017; 8:188. [PMID: 28286504 PMCID: PMC5323374 DOI: 10.3389/fimmu.2017.00188] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/09/2017] [Indexed: 11/18/2022] Open
Abstract
Molluskan hemocyanins are enormous oxygen-carrier glycoproteins that show remarkable immunostimulatory properties when inoculated in mammals, such as the generation of high levels of antibodies, a strong cellular reaction, and generation of non-specific antitumor immune responses in some types of cancer, particularly for superficial bladder cancer. These proteins have the ability to bias the immune response toward a Th1 phenotype. However, despite all their current uses with beneficial clinical outcomes, a clear mechanism explaining these properties is not available. Taking into account reports of natural antibodies against the hemocyanin of the gastropod Megathura crenulata [keyhole limpet hemocyanin (KLH)] in humans as well as other vertebrate species, we report here for the first time, the presence, in sera from unimmunized healthy donors, of antibodies recognizing, in addition to KLH, two other hemocyanins from gastropods with documented immunomodulatory capacities: Fisurella latimarginata hemocyanin (FLH) and Concholepas concholepas hemocyanin (CCH). Through an ELISA screening, we found IgM and IgG antibodies reactive with these hemocyanins. When the capacity of these antibodies to bind deglycosylated hemocyanins was studied, no decreased interaction was detected. Moreover, in the case of FLH, deglycosylation increased antibody binding. We evaluated through an in vitro complement deposition assay whether these antibodies activated the classical pathway of the human complement system. The results showed that all three hemocyanins and their deglycosylated counterparts elicited this activation, mediated by C1 binding to immunoglobulins. Thus, this work contributes to the understanding on how the complement system could participate in the immunostimulatory properties of hemocyanins, through natural, complement-activating antibodies reacting with these proteins. Although a role for carbohydrates cannot be completely ruled out, in our experimental setting, glycosylation status had a limited effect. Finally, our data open possibilities for further studies leading to the design of improved hemocyanin-based research tools for diagnosis and immunotherapy.
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Affiliation(s)
- Javier Pizarro-Bauerle
- Immunology of Microbial Aggression Laboratory, Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile , Santiago , Chile
| | - Ismael Maldonado
- Immunology of Microbial Aggression Laboratory, Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile , Santiago , Chile
| | - Eduardo Sosoniuk-Roche
- Immunology of Microbial Aggression Laboratory, Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile , Santiago , Chile
| | - Gerardo Vallejos
- Immunology of Microbial Aggression Laboratory, Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile , Santiago , Chile
| | - Mercedes N López
- Faculty of Medicine, Millennium Institute on Immunology and Immunotherapy, ICBM, Universidad de Chile, Santiago, Chile; Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile, Santiago, Chile
| | - Flavio Salazar-Onfray
- Faculty of Medicine, Millennium Institute on Immunology and Immunotherapy, ICBM, Universidad de Chile, Santiago, Chile; Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile, Santiago, Chile
| | - Lorena Aguilar-Guzmán
- Faculty of Veterinary Medicine and Livestock Sciences, University of Chile , Santiago , Chile
| | - Carolina Valck
- Immunology of Microbial Aggression Laboratory, Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile , Santiago , Chile
| | - Arturo Ferreira
- Immunology of Microbial Aggression Laboratory, Immunology Program, Faculty of Medicine, ICBM, Universidad de Chile , Santiago , Chile
| | - María Inés Becker
- Biosonda Corporation, Santiago, Chile; Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago, Chile
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18
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Immunological properties of oxygen-transport proteins: hemoglobin, hemocyanin and hemerythrin. Cell Mol Life Sci 2016; 74:293-317. [PMID: 27518203 PMCID: PMC5219038 DOI: 10.1007/s00018-016-2326-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/17/2016] [Accepted: 08/03/2016] [Indexed: 01/22/2023]
Abstract
It is now well documented that peptides with enhanced or alternative functionality (termed cryptides) can be liberated from larger, and sometimes inactive, proteins. A primary example of this phenomenon is the oxygen-transport protein hemoglobin. Aside from respiration, hemoglobin and hemoglobin-derived peptides have been associated with immune modulation, hematopoiesis, signal transduction and microbicidal activities in metazoans. Likewise, the functional equivalents to hemoglobin in invertebrates, namely hemocyanin and hemerythrin, act as potent immune effectors under certain physiological conditions. The purpose of this review is to evaluate the true extent of oxygen-transport protein dynamics in innate immunity, and to impress upon the reader the multi-functionality of these ancient proteins on the basis of their structures. In this context, erythrocyte-pathogen antibiosis and the immune competences of various erythroid cells are compared across diverse taxa.
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19
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Crystal Structure of the 3.8-MDa Respiratory Supermolecule Hemocyanin at 3.0 Å Resolution. Structure 2015; 23:2204-2212. [DOI: 10.1016/j.str.2015.09.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 09/03/2015] [Accepted: 09/14/2015] [Indexed: 11/17/2022]
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20
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On the Ultrastructure and Function of Rhogocytes from the Pond Snail Lymnaea stagnalis. PLoS One 2015; 10:e0141195. [PMID: 26488403 PMCID: PMC4619347 DOI: 10.1371/journal.pone.0141195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 10/06/2015] [Indexed: 11/19/2022] Open
Abstract
Rhogocytes, also termed "pore cells", occur as solitary or clustered cells in the connective tissue of gastropod molluscs. Rhogocytes possess an enveloping lamina of extracellular matrix and enigmatic extracellular lacunae bridged by cytoplasmic bars that form 20 nm diaphragmatic slits likely to act as a molecular sieve. Recent papers highlight the embryogenesis and ultrastructure of these cells, and their role in heavy metal detoxification. Rhogocytes are the site of hemocyanin or hemoglobin biosynthesis in gastropods. Based on electron microscopy, we recently proposed a possible pathway of hemoglobin exocytosis through the slit apparatus, and provided molecular evidence of a common phylogenetic origin of molluscan rhogocytes, insect nephrocytes and vertebrate podocytes. However, the previously proposed secretion mode of the respiratory proteins into the hemolymph is still rather hypothetical, and the possible role of rhogocytes in detoxification requires additional data. Although our previous study on rhogocytes of the red-blooded (hemoglobin-containing) freshwater snail Biomphalaria glabrata provided much new information, a disadvantage was that the hemoglobin molecules were not unequivocally defined in the electron microscope. This made it difficult to trace the exocytosis pathway of this protein. Therefore, we have now performed a similar study on the rhogocytes of the blue-blooded (hemocyanin-containing) freshwater snail Lymnaea stagnalis. The intracellular hemocyanin could be identified in the electron microscope, either as individual molecules or as pseudo-crystalline arrays. Based on 3D-electron microscopy, and supplemented by in situ hybridization, immunocytochemistry and stress response experiments, we provide here additional details on the structure and hemocyanin biosynthesis of rhogocytes, and on their response in animals under cadmium and starvation stress. Moreover, we present an advanced model on the release of synthesized hemocyanin molecules through the slit apparatus into the hemolymph, and the uptake of much smaller particles such as cadmium ions from the hemolymph through the slit apparatus into the cytoplasm.
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Matsuno A, Gai Z, Tanaka M, Kato K, Kato S, Katoh T, Shimizu T, Yoshioka T, Kishimura H, Tanaka Y, Yao M. Crystallization and preliminary X-ray crystallographic study of a 3.8-MDa respiratory supermolecule hemocyanin. J Struct Biol 2015; 190:379-82. [DOI: 10.1016/j.jsb.2015.04.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/24/2015] [Accepted: 04/27/2015] [Indexed: 10/23/2022]
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Garcia Seisdedos H, Steinberg A, Levy ED. Symmetry breaking in homo-oligomers: the curious case of mega-hemocyanin. Structure 2015; 23:3-5. [PMID: 25565100 DOI: 10.1016/j.str.2014.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Mega-hemocyanin is a 13.5 MDa oxygen transporter found in snails. It is built from three stacked rings involving ten subunits each. The cryo-EM structure of the complex presented by Gatsogiannis and colleagues in this issue of Structure revealed an unexpected breaking of 5-fold symmetry in the central ring and a nonequivalent packing of the subunits.
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Affiliation(s)
| | - Avital Steinberg
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Emmanuel D Levy
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
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