Cystine yog daim ntawv oxidized dimer ntawm cov amino acid cysteine thiab muaj cov mis (SCH2CH(NH 2)CO2H)2. Nws yog cov khoom dawb uas yog me ntsis soluble hauv dej. Nws ua haujlwm rau ob txoj haujlwm lom neeg: ib qhov chaw ntawm cov tshuaj tiv thaiv redox thiab kev sib txuas ua ke uas tso cai rau cov protein kom khaws lawv cov qauv peb sab.
YPuas cysteine oxidized lossis txo?
Vim pK ntawm cysteine yog 8.14 yog li ntawm physiologic pH 7.4 cysteine yuav nyob rau hauv oxidized daim ntawv(cystine). Yog tias koj cov kab lis kev cai nruab nrab pH tsawg dua pK ntawm thiol pawg, cysteine yuav nyob rau hauv oxidized los yog deprotonized daim ntawv. Txhawm rau tiv thaiv oxidation ntawm cysteine koj yuav tsum ntxiv 0.1M Betamercaptoethanol.
Vim li cas cysteine thiaj li ua rau oxidation?
Ntawm cov amino acids, Cysteine (Cys) yog qhov yooj yim rau oxidation los ntawm ROS vim nws cov cuab yeej nucleophilic siab. … Nyob rau hauv daim ntawv oxidised, Cys tsim disulfide daim ntawv cog lus, uas yog thawj covalent cross-links pom nyob rau hauv cov proteins, thiab stabilize lub haiv neeg conformation ntawm ib tug protein.
Yuav ua li cas cov khoom tsim thaum cysteine undergoes oxidation me ntsis?
Oxidation ntawm ob lub molecules ntawm cysteine cov ntaub ntawv cystine, ib qho molecule uas muaj cov nyiaj disulfide. Thaum ob cysteine residues nyob rau hauv ib tug protein daim ntawv cog lus, nws yog hu ua ib tug disulfide choj.
Tus nqi txo qis ntawm cysteine yog dab tsi?
Nws muaj nyob rau hauv qhov sib npaug ntawm ob daim ntawv- txo thiab oxidized. Daim ntawv txo qis yog"sulfhydryl buffer"uas tswj cov cysteine residues ntawm hemoglobin thiab lwm yam erythrocyte proteins hauv lub xeev txo. Nws kuj ua haujlwm ua detoxitant los ntawm reacting nrog hydrogen peroxide thiab organic peroxides.
