医学免疫学英文课件04-Antibody.ppt

Immunoglobulin

Xiaojianwang,Ph.D.

InstituteofImmunology

ZJUSchoolofMedicine

Tel:;immunoglobulin;immunoglobulin;Introduction;

;;1.HeavyChainandLightChain

heavychain(Hchain)

50-75Kd450-550aa

Hchains:?,?,?,?,?

Isotypes:IgM,IgG,IgA,

IgE,IgD

Lightchain(Lchain)

25Kd214aa

TypesofLchains:?,?;InanygivenIg,alltheHchainsareidentical.

Anantibodymoleculehaseithertwo?lightchainsortwo?lightchains,butneveroneofeach.

Inhumans,about60%ofAbmoleculeshave?lightchains,and40%have?lightchains.MarketchangesinthisratiocanoccurinpatientswithmonoclonalBcelltumors.;2.Variableregionandconstantregion

1)Variableregion(Vregion)

LightChain-VL(110aa)

HeavyChain-VH(110aa)

;immunoglobulin;immunoglobulin;2)Constantregion(Cregion)

Lightchain-CL(110aa)

Heavychain-CH(330-440aa)

CH1,CH2,CH3,(CH4);immunoglobulin;;Structureoftheimmunoglobulins;3DimagesoftheIgmoleculeshowthatitisnotstraightasdepictedinFigure.Itisfoldedintoglobularregions,eachofwhichcontainsanintra-chaindisulfidebond.Theseregionsarecalleddomains.

LightChainDomains-VLandCL

HeavyChainDomains-VH,CH1,CH2,CH3

IgA,IgD,IgG

(CH4inIgEandIgM);;Downloadedfrom:StudentConsult(on1June200601:58PM);immunoglobulin;II.OthercomponentsintheIg;2.Secretorypiece(SP)

Secretorycomponent(SC)isasingleglycopeptidewithMWof70KD.

Producedbymucosaepithelialcells

Functions:protectsIgA,resistproteolysisinextrasecretoryliquid.

;III.Immunoglobulinfragments;immunoglobulin;Isotype;ClassesandsubclassesofIg

IgG-?(gamma)

IgA-?(alpha)

IgM-?(Mu)

IgD-?(delta)

IgE-?(epsilon