Litlamo tsa disulfide ke karolo ea bohlokoahali ea sebopeho sa likarolo tse tharo tsa liprotheine tse ngata.Litlamo tsena tsa covalent li ka fumanoa hoo e batlang e le li-peptide tsohle tsa extracellular le limolek'hule tsa protheine.
Tlamahano ea disulfide e thehoa ha athomo ea cysteine sulfur e theha tlamo e le 'ngoe ea covalent le halofo e' ngoe ea athomo ea cystine sebabole libakeng tse fapaneng tsa protheine.Litlamo tsena li thusa ho tsitsisa liprotheine, haholo-holo tse tsoang liseleng.
Ho thehoa ka katleho ha litlamo tsa disulfide ho kenyelletsa lintlha tse 'maloa tse kang tsamaiso e nepahetseng ea li-cysteine, ho sireletsa masala a amino acid, mekhoa ea ho tlosa lihlopha tse sireletsang, le mekhoa ea ho kopanya.
Li-peptide li ile tsa hlomathiseletsoa ka litlamo tsa disulfide
Sebōpuoa sa Gutuo se na le theknoloji ea selikalikoe sa li-disulfide e butsoitseng.Haeba peptide e na le para e le 'ngoe feela ea Cys, sebopeho sa bond ea disulfide se hlakile.Li-peptide li entsoe ka mekhahlelo e tiileng kapa ea metsi,
Ka mor'a moo, e ile ea tšeloa oxidized ka tharollo ea pH8-9.The synthesis e batla e rarahane ha lipara tse peli kapa ho feta tsa li-disulfide bond li hloka ho thehoa.Leha ho theha bond ea disulfide hangata ho phetheloa morao nakong ea morero oa maiketsetso, ka linako tse ling ho hlahisoa ha preformed disulfides ho molemo bakeng sa ho hokahanya kapa ho lelefatsa liketane tsa peptide.Bzl ke sehlopha se sireletsang Cys, Meb, Mob, tBu, Trt, Tmob, TMTr, Acm, Npys, joalo-joalo, e sebelisoang haholo ho symbiont.Re sebetsa ka ho khetheha ka disulphide peptide synthesis ho kenyelletsa:
1. Lipara tse peli tsa maqhama a disulfide li thehoa ka har'a molek'hule 'me lipara tse peli tsa maqhama a disulfide li thehoa pakeng tsa limolek'hule.
2. Lipara tse tharo tsa maqhama a disulfide li thehoa ka har'a molek'hule 'me lipara tse tharo tsa maqhama a disulfide li thehoa pakeng tsa limolek'hule.
3. Insulin polypeptide synthesis, moo lipara tse peli tsa maqhama a disulfide li thehoang lipakeng tsa tatellano e fapaneng ea peptide.
4. Tšimoloho ea lipara tse tharo tsa li-peptide tse kopantsoeng le disulfide
Hobaneng ha sehlopha sa cysteinel amino (Cys) se ikhethile?
Ketane ea mahlakoreng ea Cys e na le sehlopha se sebetsang haholo.Liathomo tsa haedrojene sehlopheng sena li nkeloa sebaka habonolo ke li-radicals tsa mahala le lihlopha tse ling, 'me ka hona li ka theha maqhama a covalent le limolek'hule tse ling habonolo.
Litlamo tsa disulfide ke karolo ea bohlokoa ea sebopeho sa 3D sa liprotheine tse ngata.Litlamo tsa borokho tsa Disulphide li ka fokotsa elasticity ea peptide, tsa eketsa ho satalla, 'me tsa fokotsa palo ea litšoantšo tse ka bang teng.Moeli ona oa setšoantšo o bohlokoa bakeng sa ts'ebetso ea baeloji le botsitso ba sebopeho.Ho nkeloa sebaka ha eona ho ka ba ntho e makatsang bakeng sa sebopeho se akaretsang sa protheine.Li-amino acid tsa Hydrophobic tse kang Dew, Ile, Val ke li-helix stabilizer.Hobane e tsitsisa disulfide-bond α-helix ea sebopeho sa cysteine le haeba cysteine e sa thehe litlamo tsa disulfide.Ke hore, haeba mesaletsa eohle ea cysteine e ne e le boemong bo fokotsehileng, (-SH, e jereng lihlopha tsa mahala tsa sulfhydryl), karolo e phahameng ea likhechana tsa helical e ne e ka khoneha.
Litlamo tsa disulfide tse entsoeng ke cysteine li tšoarella ho tsitsitseng ha mohaho oa thuto e phahameng.Maemong a mangata, SS Bridges pakeng tsa litlamo li hlokahala bakeng sa ho thehoa ha mehaho ea quaternary.Ka linako tse ling masala a cysteine a theha maqhama a disulfide a arohane haholo mohahong o ka sehloohong.The topology of disulfide bonds ke motheo oa tlhahlobo ea protheine primary structure homology.Masala a cysteine a liprotheine tse homologous a bolokiloe haholo.Ke tryptophan feela e neng e bolokiloe ka lipalo ho feta cysteine.
Cysteine e bohareng ba sebaka sa catalytic sa thiolase.Cysteine e ka etsa li-acyl intermediates ka ho toba le substrate.Sebopeho se fokotsehileng se sebetsa joalo ka "sulfur buffer" e bolokang cysteine ka har'a protheine e fokotsehile.Ha pH e le tlase, tekano e rata mokhoa o fokolitsoeng oa -SH, athe libakeng tsa alkaline -SH e atisa ho ba oxidized ho theha -SR, 'me R ke ntho leha e le efe ntle le athomo ea hydrogen.
Cysteine e ka boela ea itšoara ka hydrogen peroxide le organic peroxides e le detoxicant.
Nako ea poso: May-19-2023