ANTIBODY抗体(kàngtǐ)NOBELPRIZESFORANTIBODYRESEARCH7-1DEFINITION:Antibody(Ab)Aglobulinwhichisproducedbyplasmacellasaresultoftheintroductionofanantigenandwhichhastheabilitytocombinewiththeantigenthatstimulateditsproduction.DISTRIBUTIONOFANTIBODY:Antibodymoleculesarefoundinserum,(accountforapproxinmately20%ofthetotalplasmapritein),inextravascularFluids（血管(xuèguǎn)外液体）,inexocrinesecretions(外分泌液）,andonthesurfaceofsomelymphocytes.Figure1Electrophoreticseparationofserumproteins7-2抗体(kàngtǐ)分子的基本结构BasicStructureofAbMoleculesRodneyPorter1917-1985NobelPrizein1972Figure2Thebasicstructureofimmunoglobulins/1.Heavy&lightchains1)Heavychain:①composedofabout500a.a,oligosaccharide(+)②Class:heavychain,,,,.immunoglobulin(Ig)IgA,IgG,IgMIgD,IgE2)lightchain:①composedofabout214a.a,oligosaccharide(-)②type:,6.joiningchain&secretorypiece7-4Properties&BiologicalActivitiesofFiveClassesofImmunoglobulins2.PropertiesIgGisthemajorIginserum-75%ofserumIgisIgGThelongesthalflife(t½=23days)IgGisthemajorIginextravascularspacesd)Placentaltransfere)Fixationcomplement-Notallsubclassesfixequallywell;IgG4doesnotfixcomplementf)Bindingtocells–Macrophages,monocytes,.-Opsonization.NKcell,Macrophages---mediatingADCCSPA—CoagglutinationTestIgGmolecule1.structure&presence/2.Propertiesthe3rdhighestserumIgthefirstIgmadebyfetusandBcellsintravascularIgd)Fixationcomplement–classicalpathwaye)thelargestsizeofmoleculef)agglutinatingmicrobese)Bindingtocells–Macrophages,monocytes,.-Opsonization.NKcell,Macrophages---mediatingADCC表auniqueangenicdeterminantpresentonhomogeneousAb.TheidiotypeappearstorepresenttheantigenicityoftheAg-bindingsiteofanAbandisthereforelocatedintheVregionGODmRNAIGH基因群包括95个V（50个是功能基因）、32个D、6个J以及以及9个C基因片段。其中23个D片段位于V片段之间。IGHC基因按照(ànzhào)如下顺序排列：IGHM、IGHD、IGHG3、IGHG1、IGHA1、IGHG2、IGHG4、IGHE、IGHA2。IGL基因组包括60个V（30个是功能基因，20个为假基因）、7个J基因片段和7个C区基因（3个假基因）。人IGK基因群包括70个V（约半数为假基因）、5个J基因片段和1个C区基因。IGH1.胚系基因Heavychaindiversitycreatedbyvariablerecombination1.重排基因PolyclonalAntib