Alaabta

Habka ay saamaynta isku-beddellada isku-dhafka ah isugu daraan si ay u beddelaan dhaqdhaqaaqa enzymatic maaha mid si fudud loo saadaalin karo sababtoo ah saameynahaan mar walba maaha kuwo lagu daro qaab toosan.Sidaa darteed, sifaynta saamaynta isku-beddelka isku-dhafka ah ee hadhaaga amino acid ee isku xidha substrate-ka waxay gacan weyn ka geysan kartaa fahamka gaar ahaan substrate-ka enzymes.Beta-glycosidase ee Spodoptera frugiperda (Sfbetagly), hadhaaga Q39 iyo E451 labaduba waxay la falgalaan substrate-ka tanina waxay lagama maarmaan u tahay qeexida gaar ahaan substrate-ka.Mutants labanlaab ah ee Sfbetagly (A451E39, S451E39 iyo S451N39) waxaa diyaariyey goobta-jiheeyay mutagenesis, oo lagu muujiyey bakteeriyada oo la safeeyey iyadoo la isticmaalayo affinity chromatography.Enzymes-yadan waxaa lagu gartaa iyadoo la adeegsanayo p-nitrophenyl beta-galactoside iyo p-nitrophenyl beta-fucoside sida substrates.Saamiga k bisadaha/Km ee hal iyo laba-jibbaaran ee Sfbetagly oo ka kooban is-beddellada goobta lagu hago ee boosaska Q39 iyo E451 ayaa loo adeegsaday si loo muujiyo in saameynta tamarta xorta ah ee ESdouble toorey (ka kooban enzyme-transition state complex) daggerxy) ma aha wadarta saamaynta ka dhalanaysa isku bedelka (Gdouble daggerx iyo Gdouble daggery).Farqiga u dhexeeya tooreyda Gdouble waxay tilmaamaysaa in saamaynta hal-ku-beddellayaashu ay qayb ahaan is-dul-saaran yihiin.Sidaa awgeed, saamayntan guud waxa lagu tiriyaa hal mar oo keliya gudaha Gdouble daggerxy.Xogta Crystallographic ee beta-glycosidases waxay muujinaysaa joogitaanka curaarta hydrogen bidentate ee ku lug leh hadhaaga Q39 iyo E451 iyo isla kooxda hydroxyl ee substrate-ka.Sidaa darteed, xogta heerkulbeegyada iyo xogta crystallographic labadaba waxay soo jeedinayaan in hadhaaga Q39 iyo E451 ay saameyn wadajir ah ku yeeshaan isdhexgalka ay kala leeyihiin substrate-ka.