Disulfide bond chikamu chakakosha chetatu-dimensional chimiro chemapuroteni mazhinji.Aya covalent zvisungo anogona kuwanikwa munenge ese extracellular peptides uye mapuroteni mamorekuru.
A disulfide bond inoumbwa apo cysteine sarufa atomu inoumba covalent imwechete bond neimwe hafu yecystine sulfur atomu panzvimbo dzakasiyana muprotein.Izvi zvisungo zvinobatsira kudzikamisa mapuroteni, kunyanya ayo akavanzwa kubva kumasero.
Kugadzirwa kwakanaka kwedisulfide bonds kunosanganisira zvinhu zvakati senge manejimendi akakodzera ecysteines, kuchengetedzwa kweamino acid masara, nzira dzekubvisa dzemapoka ekudzivirira, uye nzira dzekubatanidza.
Peptides yakabatanidzwa nemabhondi edisulfide
Gutuo organism ine mature disulfide bond ring technology.Kana iyo peptide iine peya imwe chete yeCys, iyo disulfide bond kugadzirwa kwakatwasuka.Peptides inogadzirwa muzvikamu zvakasimba kana zvemvura,
Yakazoiswa oxidized mune pH8-9 mhinduro.Iyo synthesis yakaoma kana maviri kana anopfuura maviri maviri e disulfide bond anoda kuumbwa.Kunyangwe disulfide kuumbwa kwechisungo kunowanzo kupedzwa kunonoka muchirongwa chekugadzira, dzimwe nguva kuunzwa kwe preformed disulfides kune zvakanakira kubatanidza kana kurebesa peptide cheni.Bzl iboka reCys rinodzivirira, Meb, Mob, tBu, Trt, Tmob, TMTr, Acm, Npys, nezvimwewo, rinoshandiswa zvakanyanya musymbiont.Isu tinonyanya kuita disulphide peptide synthesis inosanganisira:
1. Maviri maviri e disulfide bond anoumbwa mukati memorekuru uye maviri maviri e disulfide bond anoumbwa pakati pemamorekuru.
2. Zvitatu zviviri zvedisulfide zvisungo zvinoumbwa mukati memorekuru uye mapaya matatu e disulfide bond anoumbwa pakati pemamorekuru.
3. Insulin polypeptide synthesis, apo maviri maviri e disulfide bond anoumbwa pakati pezvakasiyana peptide sequences.
4. Kuumbwa kwezviviri zvitatu zve disulfide-bonded peptides
Nei cysteineyl amino boka (Cys) yakakosha?
Iyo yepadivi cheni yeCys ine inoshanda chaizvo reactive boka.Maatomu ehaidhirojeni ari muboka iri anotsiviwa zviri nyore nemahara radicals nemamwe mapoka, uye nekudaro anogona kugadzira covalent zvisungo zviri nyore nemamwe mamorekuru.
Disulfide zvisungo chikamu chakakosha cheiyo 3D chimiro chemapuroteni mazhinji.Disulphide bhiriji zvisungo zvinogona kuderedza elasticity ye peptide, kuwedzera kuomarara, uye kuderedza huwandu hwemifananidzo inogona.Iyi mipimo yemufananidzo yakakosha pakuita kwebiology uye kugadzikana kwechimiro.Kutsiviwa kwayo kungave kunoshamisa kune chimiro chese cheprotein.Hydrophobic amino acids akadai seDew, Ile, Val ndeye helix stabilizer.Nokuti inogadzirisa disulfide-bond α-helix ye cysteine formation kunyange kana cysteine isingaiti disulfide bonds.Ndiko kuti, kana zvose zvakasara zve cysteine mumamiriro ezvinhu akaderedzwa, (-SH, akatakura mahara sulfhydryl mapoka), chikamu chepamusoro chezvimedu zvehelical zvingaita.
Izvo zvisungo zve disulfide zvakaumbwa ne cysteine zvinogara kune kugadzikana kwechimiro chepamusoro.Muzviitiko zvakawanda, SS Bridges pakati pezvisungo zvakakosha pakuumbwa kwequaternary zvivakwa.Dzimwe nguva cysteine masara anoumba disulfide zvisungo ari kure kure mukutanga chimiro.Iyo topology ye disulfide bonds ndiyo hwaro hwekuongororwa kweprotein yekutanga chimiro homology.Iyo cysteine masara ehomologous mapuroteni akachengetedzwa zvakanyanya.Chete tryptophan yaive yakachengetedzwa zvakanyanya kupfuura cysteine.
Iyo cysteine inowanikwa pakati peiyo catalytic saiti ye thiolase.Cysteine inogona kugadzira acyl intermediates zvakananga ne substrate.Iyo yakaderedzwa fomu inoita se "sarufa buffer" inochengeta cysteine muprotein mune yakaderedzwa.Kana pH yakadzikira, kuenzana kunofarira iyo yakaderedzwa -SH fomu, nepo munzvimbo dzealkaline -SH inowanzoita oxidized kuumba -SR, uye R chero chinhu kunze kweatomu rehydrogen.
Cysteine inogonawo kuita nehydrogen peroxide uye organic peroxides se detoxicant.
Nguva yekutumira: May-19-2023