生物化学 第十讲 Biomembrane Transport-3

§10Biomembrane&Transport§10.1Introduction§10.2Passivetransport§10.3

Activetransport1Classesoftransporters(permeases)Channels(gate-like)Carriers(enzyme-like)PassivetransportersActivetransportersPrimaryactivetransporters(needATPorlight)Secondaractivetransporters(needelectrochemicalgradientdirectly,ATPindirectly)23LactoseuptakeinE.coli4Glucosetransportinintestinalepithelialcells5FourtypesofATP-poweredtransporters6FamilyBacteriaArchaeaFungiPlantsInvertebratesVertebratesSpecificityFunctionP1a√√K+TurgorpressureregulationP1b√√√√√√Cu+,Cu2+,Ag+,Cd2+,Zn2+,Pb2+,Co2+Detoxification,traceelementhomeostasisP2a√√√√√√Ca2+,Mn2+(incl.SERCA)Ca2+transport,signaling,musclerelaxation,traceelementhomeostasisP2b√√√√Ca2+(incl.PMCA)Ca2+transport(PM),signalingP2c√√√Na+/K+,H+/K+PMpotential,kidneyfunction,stomachacidificationP2d√√Na+,Ca2+UnknownP3a√√√√H+PMpotential,pHhomeostasisP3b√Mg2+UnknownP4√√√√PhospholipidsLipidtransport,lipid-bilayerasymmetryP5√√√√UnknownUnknownP-typeATPasesubfamiliesP:refertothephosphorylatedintermediateataconservedAspresidue7ER,endoplasmicreticulum;SR,sarcopalsmicreticulum;PL,phospholipid;PM,plasmamembrane;HA,H+-ATPase;HKA,H+/K+-ATPase;HMA,heavy-metal-transportingATPase;PMCA,PMCa2+ATPase;SERCA,sarco(endo)palsmicreticulumCa2+ATPase;SPCA,sceretorypathwayCa2+ATPase;NKA,Na+/K+-ATPase8StructuralfeatureofP-typeATPase(e.gSERCA)Domains:

ActuatorNnucleotidebindingPphosphorylationTtransportSupportRregulatory,atNorCterminus(orboth).M9FourStructuresthathavebeendeterminedRdomain10ActionModelofSERCA11ActionModelofNKA12FourtypesofATP-poweredtransporters13为什么上述过程的能量不是直接与ATP合成偶联，而总是通过电化学梯度相偶联？positivelychargedsidenegativelychargedside14151617Photosynthesis:Overview1819ThestructurewasassembledbyeyeaccordingtoPDBdata：thecringofIlyobactertartaricus(1CYE),theF1organizationofEscherichiacoli(1JNV),theδ-subunitofE.coli(2A7U),theperipheralstalkfrombovinemitochondria(2CLY),andthemembranouspartofsubunitbofE.coli(1B9U).Nohigh-resolutionstructuraldataareavailableforsubunitaandthehingeregionofsubunitb.TheillustrationwascreatedusingPyMOLF1:thefirstfactorrecognizedasessentialforoxidativephosphorylationFO:odenotingoligomycin-sensitive2021ATP-dependentcross-linking,PNAS,92,10964-10968,1995转动机理的证明(1)22Nature386,299-302(1997)转动机理的证明(2)g亚基的旋转23Science286,1722-1724(1999)

转动机理的证明(3)C-group的旋转24Proc.NatlAcad.Sci.USA97,7243-7247

(2000)Cy3转动机理的证明(4)减少了actin对g旋转的影响25PNAS100,9314-9318(2003)转动机理的证明(5)能量共振传递，验证g旋转与b亚基功能的关系26转动机理的证明(6)simultaneousobservationofnucleotidekineticsandrotation.NatureStructural&MolecularBiology11,142-148(2004)27机械驱动ATP合成

Nature427,465-468(2004)转动机理的证明(7)28FOF1FOF1Fo-ab2Fo-cnF1-

F1-

3

3

Fo-cn:ForotorF1-/:F1rotorFo-ab2:FostatorF1-

3

3

:F1statorRotorStatorATPaseATPase的转动机构/原理(1)29ATPase的转动机构/原理(2)30ATPase的转动机构/原理(3)31AsporGlu

ArgATPase的转动机构/原理(4)3233ATP的合成过程34(freeATPinsolution)ATP合成的热力学(Ontheenzymesurface)35FourtypesofATP-poweredtransporters36ATPBindingCassettesuperfamilyThelargestclassesoftransportersSubstrates：fromionstomacromoleculesABCtranspotersImporters:seemtobepresentexclusivelyinprokaryoticorganismsExporters:inbotheukaryotesandprokaryoticorganismsType1Type237FourcoredomainsandmechanismofABCtransportersTMD:transmembranedomainNBD:nucleotidebindingdomain;ABC:ATPbin