Zomangira za disulfide ndi gawo lofunikira kwambiri lamagulu atatu a mapuloteni ambiri.Zomangira zolumikizanazi zitha kupezeka pafupifupi pafupifupi ma peptides onse akunja ndi mamolekyu a protein.
Mgwirizano wa disulfide umapangidwa pamene atomu ya sulfure ya cysteine imapanga mgwirizano umodzi umodzi ndi theka lina la atomu ya sulfure ya cystine pa malo osiyanasiyana mu mapuloteni.Zomangirazi zimathandiza kukhazikika kwa mapuloteni, makamaka omwe amatulutsidwa kuchokera ku maselo.
Kupanga bwino kwa zomangira za disulfide kumaphatikizapo zinthu zingapo monga kasamalidwe koyenera ka cysteines, kuteteza zotsalira za amino acid, njira zochotsera magulu oteteza, ndi njira zophatikizira.
Ma peptides adalumikizidwa ndi zomangira za disulfide
Gutuo chamoyo chili ndi luso la mphete la disulfide lokhwima.Ngati peptide ili ndi ma Cys amodzi okha, mapangidwe a mgwirizano wa disulfide ndiwolunjika.Ma peptides amapangidwa mu magawo olimba kapena amadzimadzi,
Kenako idathiridwa okosijeni mu njira ya pH8-9.Kuphatikizikako kumakhala kovuta kwambiri pamene awiri kapena angapo a ma disulfide amayenera kupangidwa.Ngakhale kupanga ma bond a disulfide nthawi zambiri kumamalizidwa mochedwa pakupanga, nthawi zina kuyambitsa kwa preformed disulfides kumakhala kopindulitsa pakulumikiza kapena kukulitsa unyolo wa peptide.Bzl ndi gulu loteteza Cys, Meb, Mob, tBu, Trt, Tmob, TMTr, Acm, Npys, ndi zina, zomwe zimagwiritsidwa ntchito kwambiri mu symbiont.Timakonda kwambiri disulphide peptide synthesis kuphatikiza:
1. Ma awiriawiri a zomangira disulfide amapangidwa mkati mwa molekyulu ndipo awiri awiri a disulfide zomangira amapangidwa pakati pa mamolekyu.
2. Magulu atatu a zomangira za disulfide amapangidwa mkati mwa molekyulu ndipo magawo atatu a zomangira za disulfide amapangidwa pakati pa mamolekyu.
3. Insulin polypeptide kaphatikizidwe, pomwe awiriawiri a zomangira za disulfide amapangidwa pakati pamitundu yosiyanasiyana ya peptide.
4. Kaphatikizidwe ka ma peptides atatu opangidwa ndi disulfide
Chifukwa chiyani cysteinel amino gulu (Cys) ndi lapadera kwambiri?
Unyolo wam'mbali wa Cys uli ndi gulu logwira ntchito kwambiri.Ma atomu a haidrojeni m'gululi amasinthidwa mosavuta ndi ma radicals aulere ndi magulu ena, motero amatha kupanga maubwenzi ogwirizana ndi mamolekyu ena.
Zomangira za disulfide ndizofunikira kwambiri pakupanga kwa 3D kwa mapuloteni ambiri.Zomangira za mlatho wa disulphide zimatha kuchepetsa kukhazikika kwa peptide, kukulitsa kuuma, ndikuchepetsa kuchuluka kwa zithunzi zomwe zingatheke.Kuchepetsa kwazithunzi kumeneku ndikofunikira pazachilengedwe komanso kukhazikika kwadongosolo.Kulowetsedwa kwake kungakhale kodabwitsa chifukwa cha kapangidwe kake ka mapuloteni.Hydrophobic amino acid monga Dew, Ile, Val ndi helix stabilizer.Chifukwa imakhazikitsa disulfide-bond α-helix ya mapangidwe a cysteine ngakhale ngati cysteine sapanga zomangira za disulfide.Ndiko kuti, ngati zotsalira zonse za cysteine zinali zochepetsedwa, (-SH, zonyamula magulu a sulfhydryl aulere), chiwerengero chachikulu cha zidutswa za helical zingatheke.
Zomangira za disulfide zopangidwa ndi cysteine zimakhala zolimba kukhazikika kwa dongosolo lapamwamba.Nthawi zambiri, SS Bridges pakati pa zomangira ndizofunikira kuti pakhale mapangidwe a quaternary.Nthawi zina zotsalira za cysteine zomwe zimapanga zomangira za disulfide zimakhala zotalikirana muzoyambira zoyambirira.The topology of disulfide bonds ndiye maziko a kusanthula kwa protein primary structure homology.Zotsalira za cysteine mapuloteni a homologous ndizotetezedwa kwambiri.Tryptophan yokha ndiyomwe idasungidwa mochuluka kuposa cysteine.
Cysteine ili pakatikati pa malo othandizira a thiolase.Cysteine ikhoza kupanga acyl intermediates mwachindunji ndi gawo lapansi.Mawonekedwe ochepetsedwa amakhala ngati "sulfur buffer" yomwe imasunga cysteine m'mapuloteni m'malo ochepetsedwa.Pamene pH ili yochepa, kufanana kumakonda kuchepetsedwa -SH mawonekedwe, pamene m'madera amchere -SH imakhala yowonjezereka kuti ikhale ndi oxidized kupanga -SR, ndipo R ndi chirichonse koma atomu ya haidrojeni.
Cysteine imathanso kuchitapo kanthu ndi hydrogen peroxide ndi organic peroxides ngati detoxicant.
Nthawi yotumiza: May-19-2023