Alaabta

Fikradaha farsamada ee qoyska Ca2+ ku tiirsan ee alfa-mannosidases ee ku jira astaamaha mindhicirka aadanaha.

Bakteeriyada mindhicirka, oo ay tusaale u tahay Bacteroides thetaiotaomicron, ayaa door muhiim ah ka ciyaarta ilaalinta caafimaadka bini'aadamka iyada oo ka faa'iidaysanaysa qoysaska waaweyn ee glycoside hydrolases (GHs) si ay uga faa'iidaystaan ​​​​polysaccharides cuntada iyo martida glycans nafaqo ahaan.Balaadhinta qoyska GH ee noocan oo kale ah waxaa tusaale u ah qoyska 23 ee GH92 glycosidases oo ay dejiyeen genome B. thetaiotaomicron.Halkan waxaan ku tusinaynaa in kuwani ay yihiin alfa-mannosidases kuwaas oo u dhaqma iyada oo loo marayo habka barokaca si loo isticmaalo N-glycans martida loo yahay.Qaab dhismeedka saddex-geesoodka ah ee laba GH92 mannosidases wuxuu qeexayaa qoys ka kooban laba-domain borotiinno kaas oo xarunta catalytic ay ku taal interface interface, bixinta acid (glutamate) iyo saldhigga (aspartate) caawinta hydrolysis ee Ca (2+) - hab ku tiirsan.Qaab dhismeedka saddex-geesoodka ah ee GH92s ee kakan oo leh horjoogayaasha ayaa bixiya aragti gaar ah, habka iyo habka qaabaynta ee catalysis.Ca(2+) waxa ay door muhiim ah ka ciyaartaa in ay ka leexiso mannoside-ka ka fogaanshaheeda (4)C(1) kursi ku wanagsan xaalada kala guurka (Bibliography: Nat.Chem.Biyo.6, 125-32, (2010)

Xidhiidhka hore ee chromatography ee ovalbumin glycoasparagines oo ku yaal tiirka concanavalin A-sepharose.Daraasad tiro-koob ah oo gaar ah oo ku xidhan lectin.

Isdhexgalka Sepharose 4B-immobilized concanavalin A (ConA) oo leh 10 glycoasparagines oo laga soo qaatay ovalbumin ayaa lagu baaray tiro ahaan iyadoo la adeegsanayo chromatography affinity hore.Habkan, xal karbohaydrayt ah ayaa si joogto ah loogu dabaqaa tiirka ConA-Sepharose iyo dib u dhigista hore ee elution waxaa lagu qiyaasaa sida cabbirka xoogga isdhexgalka.Kala fogaanshaha joogtada ah (Kd) saccharide kasta oo leh ConA waa la go'aamin karaa.Falanqaynta xiritaanka p-nitrophenyl-alpha,D-mannoside waxay muujisay in sifooyinka ConA aysan isbeddelin asal ahaan ka dib marka la dhaqaajiyo Sepharose 4B.Mid kasta oo ka mid ah ovalbumin glycoasparagines waxaa lagu calaamadeeyay tritium habka methylation-ka dhimista ee falanqaynta.Isbarbardhigga qiyamka Kd ee la helay ayaa muujiyay in isku xidhka ConA ay si aad ah ugu kala duwan tahay kala duwanaanshiyaha qaab-dhismeed ee silsiladda glycosyl.Natiijooyinku waxay soo jeedinayaan in ConA ay aqoonsato qaab-dhismeedka silsiladda glycosyl gaar ah, Man alpha 1-6 (Man alpha 1-3) Man, kaas oo ugu yaraan hal koox hydroxyl ah oo ku taal booska C-3 ee mannose-ku-xiran yahay C-6 waa inay ahaataa mid bilaash ah.