6533b7cefe1ef96bd1257bff

RESEARCH PRODUCT

Ligation Tunes Protein Reactivity in an Ancient Haemoglobin: Kinetic Evidence for an Allosteric Mechanism in Methanosarcina acetivorans Protoglobin

Marco NardiniMassimo ColettaPaolo AscenziFilip DesmetChiara CiaccioCristiano ViappianiCristiano ViappianiStefano BrunoLuc MoensSabine Van DoorslaerSylvia DewildeStefania AbbruzzettiStefania AbbruzzettiMartino BolognesiL. Tilleman

subject

HEME ENVIRONMENTStereochemistrySILICA-GELSArchaeal ProteinsAllosteric regulationKineticsBiophysicslcsh:MedicinePlasma protein bindingBiochemistryDissociation (chemistry)HemoglobinsAllosteric RegulationBINDINGINTERNAL HYDROPHOBIC CAVITIESMoleculeGlobinFerrous CompoundsMethanosarcina acetivoransSettore BIO/10lcsh:ScienceBiologyT STATE HEMOGLOBINCarbon MonoxideMultidisciplinaryPhotolysisbiologyChemistryPhysicslcsh:RProteinsMethanosarcinabiology.organism_classificationRecombinant ProteinsEnzymesGlobinsKineticsOXYGEN-AFFINITYBiochemistryMethanosarcinaARABIDOPSIS-THALIANAlcsh:QGLOBIN-COUPLED SENSORSHuman medicineProtein MultimerizationLIGAND MIGRATIONNEUROGLOBINResearch ArticleProtein Binding

description

Abstract: Protoglobin from Methanosarcina acetivorans (MaPgb) is a dimeric globin with peculiar structural properties such as a completely buried haem and two orthogonal tunnels connecting the distal cavity to the solvent. CO binding to and dissociation from MaPgb occur through a biphasic kinetics. We show that the heterogenous kinetics arises from binding to (and dissociation from) two tertiary conformations in ligation-dependent equilibrium. Ligation favours the species with high binding rate (and low dissociation rate). The equilibrium is shifted towards the species with low binding (and high dissociation) rates for the unliganded molecules. A quantitative model is proposed to describe the observed carbonylation kinetics.

yearjournalcountryeditionlanguage
2012-03-01
10.1371/journal.pone.0033614https://publications.cnr.it/doc/200059