Qhov sib txawv tseem ceeb ntawm N-txuas thiab O-txuas oligosaccharides yog tias N-txuas oligosaccharides tsim thaum N atoms ntawm cov protein khi nrog cov suab thaj, qhov O-txuas oligosaccharides tsim thaum O atoms ntawm serine los yog threonine khi nrog a qab zib.
Oligosaccharides yog cov carbohydrate molecules uas muaj peb mus rau rau qhov ntawm monosaccharides lossis cov suab thaj yooj yim. N-txuas oligosaccharides yog carbohydrate molecules qhov twg ib qho oligosaccharide txuas mus rau nitrogen atom. O-linked oligosaccharides, ntawm qhov tod tes, yog ib hom carbohydrates uas cov piam thaj molecule txuas nrog cov pa atom ntawm serine lossis threonine residue hauv cov protein.
N-txuas Oligosaccharides yog dab tsi?
N-txuas oligosaccharides yog carbohydrate molecules uas nws oligosaccharides txuas rau nitrogen atoms. Qhov no tshwm sim los ntawm cov txheej txheem ntawm N-glycosylation. Oligosaccharides yog cov carbohydrate compounds uas muaj ntau lub suab thaj molecules. Cov no qee zaum hu ua "glycans." Hauv cov txheej txheem ntawm N-txuas glycosylation, nitrogen atom feem ntau yog los ntawm amide nitrogen ntawm asparagine residue ntawm cov protein. Cov txheej txheem no tau piav qhia zoo tshaj plaws hauv thaj chaw biochemistry.
Feem ntau, N-txuas glycosylation tshwm sim hauv ntau cov protein eukaryotic. Ntawm eukaryotes, qhov no tshwm sim dav hauv archaea tab sis tsis tshua muaj kab mob. Peb tuaj yeem txiav txim siab qhov xwm txheej ntawm N-txuas oligosaccharide uas txuas nrog glycoprotein los ntawm cov protein thiab cov cell uas nws tau qhia. Hom N-txuas oligosaccharide kuj nyob ntawm hom kab mob.
Nyob hauv glycoprotein, feem ntau muaj ob hom kev sib cog lus: kev sib cog lus ntawm saccharide residues hauv glycan thiab kev sib cog lus ntawm glycan saw thiab cov protein molecule. Nyob ntawd, cov khoom qab zib tau sib koom ua ke los ntawm glycosidic bonds. Cov glycosidic bonds feem ntau yog C1-C4 daim ntawv cog lus. Tsis tas li ntawd, kev sib cog lus ntawm oligosaccharide thiab cov protein seem yuav tsum muaj kev lees paub ntawm qhov kev pom zoo ua ntu zus.
O-txuas Oligosaccharides yog dab tsi?
O-txuas ntxiv oligosaccharides yog ib hom carbohydrates uas cov piam thaj molecule txuas mus rau ib qho oxygen atom ntawm serine lossis threonine residue hauv cov protein. Cov txheej txheem ntawm kev tsim daim ntawv cog lus no yog hu ua O-linked glycosylation. Nws yog cov txheej txheem kev hloov pauv hloov pauv uas tshwm sim tom qab kev sib txuas ntawm cov protein.
Thaum xav txog eukaryotes, qhov kev sib txuas no tshwm sim hauv endoplasmic reticulum, Golgi apparatus, thiab qee zaum hauv cytoplasm. Hauv prokaryotes, qhov no tshwm sim hauv cytoplasm. Muaj ntau ntau hom suab thaj uas tuaj yeem khi nrog serine lossis threonine. Qhov kev khi no tuaj yeem cuam tshuam rau cov protein ntau ntau. E.g. kev lag luam ntawm cov hlwb hauv lub cev tiv thaiv kab mob, uas tso cai rau kev lees paub ntawm cov khoom txawv teb chaws.
Qhov txawv ntawm N-txuas thiab O-txuas Oligosaccharides yog dab tsi?
N-txuas oligosaccharides yog carbohydrate molecules qhov twg cov oligosaccharide txuas nrog nitrogen atom, thaum O-linked oligosaccharides yog hom carbohydrates uas cov piam thaj molecule txuas nrog oxygen atom ntawm serine lossis threonine residue hauv ib protein ntau. Yog li ntawd, qhov sib txawv tseem ceeb ntawm N-txuas thiab O-txuas oligosaccharides yog tias N-txuas oligosaccharides tsim thaum N atom ntawm cov protein khi nrog cov suab thaj thaum O-txuas oligosaccharides tsim thaum O atoms ntawm serine los yog threonine khi nrog cov suab thaj.
Cov ntawv qhia hauv qab no nthuav tawm qhov sib txawv ntawm N-txuas thiab O-txuas oligosaccharides hauv daim ntawv tabular rau ib sab ntawm kev sib piv.
Summary – N-linked vs O-linked Oligosaccharides
Oligosaccharides yog hom qab zib molecule. Qhov sib txawv tseem ceeb ntawm N-txuas thiab O-txuas oligosaccharides yog tias N-txuas oligosaccharides tsim thaum N atoms ntawm cov protein khi nrog cov suab thaj, qhov O-txuas oligosaccharides tsim thaum O atoms ntawm serine los yog threonine khi nrog qab zib.
