文档介绍：!"#$%&'()*+, -.!"#/0%&$123 1, Complementary InteractionsbetweenProteinsandLigands: The ImmuneSystemandImmunoglobulins 2, Forcestostabilizetheprotein3-Dstructure 3, proteinstructureprediction 1, Complementary Interactionsbetween ProteinsandLigands: The ImmuneSystemand Immunoglobulins “StructuralImmunology” Whenaforeignsubstance-avirus, abacterium, or evenaforeign protein-invadesthetissuesofa higher vertebrate(4567)(likeahuman), the organismdefends itself bywhatiscalledthe immuneresponse (89:;<89=:). The immuneresponse is afirstline ofdefense against infection andprobablyagainstcancer cellsaswell. The immune response has two facets(>?): 1. Humoralimmune response (***@A89:;)- ells(BCDE) called B lymphocytes synthesize specificimmunoglobulin(89F!") molecules that areexcreted(GH) from the celland bind to the invading substance. Binding either precipitatesthe foreignsubstance or marksit for destruction by cells calledmacrophages(IJDE). 2. Cellular immuneresponse (DE89:;) - ellscalled Tlymphocytes,bearing immunoglobulin-like molecules on their surfaces, recognizeandkillforeignor aberrant(KL$) cells. AntigensandAntibodies: Theforeignsubstancethatelicits(MN)an immune response iscalledthe antigen(OP). Aspecific immunoglobulinthatbindstotheantigen iscalledthe antibody(O@). Ifthe invadingparticle is large, likeacell, avirus, or aprotein, manydifferentantibodiesmaybeelicited, eachtypebindingspecificallytoanantigenic determinant(or epitope, OPQRS)onthesurface oftheparticle. ImmunoglobulinStructure – Eachimmunoglobulinmonomerconsistsoffourchains, twoheavychains(M=53,000each)and twolightchains (M=23,000each), heldtogetherbydisulfidebonds. Ineachchainare constantdomains(identicalinall antibodiesofagivenclass)anda variabledomain. Variationsintheaminoacidsequence(andthereforethe tertiarystructure)ofthevariabledomainsofthe lightand heavychainsconfer(TU)themultitudinous(VWVX$) specificitiesofantigenstodifferentdeterminants. PrecipitatingAntigens-A la