0000000000236329

AUTHOR

Christos Gatsogiannis

0000-0002-4922-4545

showing 8 related works from this author

Nautilus pompilius Hemocyanin: 9 Å Cryo-EM Structure and Molecular Model Reveal the Subunit Pathway and the Interfaces between the 70 Functional Units

2007

Hemocyanins are giant extracellular oxygen carriers in the hemolymph of many molluscs. Nautilus pompilius (Cephalopoda) hemocyanin is a cylindrical decamer of a 350 kDa polypeptide subunit that in turn is a "pearl-chain" of seven different functional units (FU-a to FU-g). Each globular FU has a binuclear copper centre that reversibly binds one O(2) molecule, and the 70-FU decamer is a highly allosteric protein. Its primary structure and an 11 A cryo-electron microscopy (cryo-EM) structure have recently been determined, and the crystal structures of two related FU types are available in the databanks. However, in molluscan hemocyanin, the precise subunit pathway within the decamer, the inter…

Models MolecularMolecular modelProtein Conformationmedicine.medical_treatmentProtein subunitMolecular Sequence DataOctopodiformesAllosteric regulationBiologyHemocyaninTurn (biochemistry)Protein structureStructural BiologyImage Processing Computer-AssistedmedicineAnimalsAmino Acid SequenceMolecular BiologyBinding SitesSequence Homology Amino AcidCryoelectron MicroscopyProtein primary structureHemocyaninCrystallographyHemocyaninsBiophysicsNautilusProtein quaternary structureJournal of Molecular Biology
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Allosterism of Nautilus pompilius hemocyanin as deduced from 8 Å cryo-EM structures obtained under oxy and deoxy conditions

2008

Hemocyanins are the blue copper-containing respiratory proteins of many molluscs. Nautilus pompilius hemocyanin (NpH) is a cylindrical decamer composed of ten copies of a 350 kDa polypeptide subunit, in turn consisting of seven O2-binding functional units (FUs, termed NpH-a to NpH-g). Ten copies of the subunit segment NpH-a to NpH-f form the cylinder wall (ca. 35 nm in diameter), whereas the ten copies of NpH-g build the internal collar. Recently we published a 9A cryo-EM structure and molecular model of NpH that solved the principal architecture of this protein [1]. Hemocyanins are highly allosteric, and the cooperativity of oxygen binding should be transferred between functional units by …

Turn (biochemistry)CrystallographyMolecular modelCryo-electron microscopyProtein subunitmedicine.medical_treatmentmedicineCooperativityHemocyaninContext (language use)AnatomyBiologyOxygen binding
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3D cryo-electron microscopy, molecular modelling and structural fitting with recombinant expressed virus like particles as part of drug design

2007

Extended abstract of a paper presented at MC 2007, 33rd DGE Conference in Saarbrücken, Germany, September 2 – September 7, 2007

CrystallographyMaterials scienceCryo-electron microscopylawRecombinant DNAInstrumentationViruslaw.inventionMicroscopy and Microanalysis
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Keyhole limpet hemocyanin: 9-A CryoEM structure and molecular model of the KLH1 didecamer reveal the interfaces and intricate topology of the 160 fun…

2008

Abstract Hemocyanins are blue copper-containing respiratory proteins in the hemolymph of many arthropods and molluscs. Molluscan hemocyanins are decamers, didecamers, or multidecamers of a 340- to 400-kDa polypeptide subunit containing seven or eight globular functional units (FUs; FU-a to FU-h), each with an oxygen-binding site. The decamers are short 35-nm hollow cylinders, with their lumen narrowed by a collar complex. Our recently published 9-A cryo-electron microscopy/crystal structure hybrid model of a 3.4-MDa cephalopod hemocyanin decamer [Nautilus pompilius hemocyanin (NpH)] revealed the pathway of the seven-FU subunit (340 kDa), 15 types of inter-FU interface, and an asymmetric col…

Models MolecularMolecular modelbiologySequence Homology Amino AcidCryo-electron microscopyProtein subunitmedicine.medical_treatmentCryoelectron MicroscopyMolecular Sequence DataOxygen transportHemocyaninCrystallographyBiopolymersStructural BiologyHemolymphHemocyaninsmedicinebiology.proteinAnimalsProtein quaternary structureAmino Acid SequenceMolecular BiologyKeyhole limpet hemocyaninJournal of molecular biology
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8 Å cryo-TEM and single particle analysis of Nautilus pompilius hemocyanin under two states of oxygenation

2007

Extended abstract of a paper presented at MC 2007, 33rd DGE Conference in Saarbrücken, Germany, September 2 – September 7, 2007

Cryo temMaterials sciencebiologymedicine.medical_treatmentmedicineBiophysicsSingle particle analysisHemocyaninOxygenationNautilusbiology.organism_classificationInstrumentationMicroscopy and Microanalysis
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9 Å cryo-EM structure and molecular model of a gastropod hemocyanin didecamer (KLH1) reveals the architecture of the asymmetric collar

2008

Hemocyanins are blue copper proteins that transport oxygen in the hemolymph of many arthropods and molluscs. Molluscan hemocyanins are decamers, didecamers or multidecamers of a 350–400 kDa polypeptide subunit that is subdivided into seven or eight different functional units (FUs, each with a single copper active site). The quaternary structure is a semi-hollow cylinder consisting of a wall and a collar. Recently, we published a 9 A cryo-EM structure and molecular model of a cephalopod hemocyanin decamer (NpH, from Nautilus pompilius) that answered many hitherto unsolved questions concerning the quaternary structure of molluscan hemocyanin. Notably, it revealed the twisted pathway of the 10…

Molecular modelbiologyChemistryStereochemistryCopper proteinmedicine.medical_treatmentProtein subunitActive siteHemocyaninAnatomybiology.organism_classificationCephalopodHemolymphbiology.proteinmedicineProtein quaternary structure
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Structure of Mega-Hemocyanin Reveals Protein Origami in Snails

2014

SummaryMega-hemocyanin is a 13.5 MDa oxygen transporter found in the hemolymph of some snails. Similar to typical gastropod hemocyanins, it is composed of 400 kDa building blocks but has additional 550 kDa subunits. Together, they form a large, completely filled cylinder. The structural basis for this highly complex protein packing is not known so far. Here, we report the electron cryomicroscopy (cryo-EM) structure of mega-hemocyanin complexes from two different snail species. The structures reveal that mega-hemocyanin is composed of flexible building blocks that differ in their conformation, but not in their primary structure. Like a protein origami, these flexible blocks are optimally pac…

Models MolecularProtein FoldingCryo-electron microscopymedicine.medical_treatmentGastropodaSnailsNanotechnologySnailBiologyMega-Cylinder (gastropod)Structural Biologybiology.animalHemolymphmedicineAnimalsProtein Structure QuaternaryMolecular BiologyCryoelectron MicroscopyProtein primary structureHemocyaninbiology.organism_classificationProtein SubunitsComplex proteinHemocyaninsBiophysicsProtein MultimerizationStructure
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Comparative 11A structure of two molluscan hemocyanins from 3D cryo-electron microscopy

2006

Abstract Hemocyanins are giant extracellular proteins that transport oxygen in the hemolymph of many molluscs. Molluscan hemocyanins are cylindrical decamers or didecamers of a 350–400 kDa subunit that contains seven or eight different covalently linked globular functional units (FUs), arranged in a linear manner. Each FU carries a single copper active site and reversibly binds one dioxygen molecule. As a consequence, the decamer can carry up to 70 or 80 O 2 molecules. Although complete sequence information is now available from several molluscan hemocyanins, many details of the quaternary structure are still unclear, including the topology of the 10 subunits within the decamer. Here we sho…

Models MolecularTransport oxygenCryo-electron microscopyMacromolecular Substancesmedicine.medical_treatmentProtein subunitGeneral Physics and AstronomyHemocyaninStructural BiologyHemolymphmedicineImage Processing Computer-AssistedAnimalsGeneral Materials ScienceProtein Structure QuaternarybiologyResolution (electron density)Cryoelectron MicroscopyActive siteHemocyaninCell BiologyCrystallographyMolluscaHemocyaninsbiology.proteinProtein quaternary structure
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