Qhov txawv ntawm EDTA thiab EGTA

2024 Tus sau: Alex Aldridge | [email protected]. Kawg hloov kho: 2023-12-17 13:40

EDTA vs EGTA

EDTA thiab EGTA ob leeg yog cov neeg ua haujlwm chelate. Ob leeg yog polyamino carboxylic acids thiab muaj ntau dua lossis tsawg dua cov khoom qub.

EDTA

EDTA yog lub npe luv rau Ethylene diamine tetraacetic acid. Nws tseem hu ua (ethylene dinitrilo) tetraacetic acid. Hauv qab no yog cov qauv ntawm EDTA.

Lub EDTA molecule muaj rau qhov chaw uas muaj hlau ion tuaj yeem khi. Muaj ob pawg amino thiab plaub pawg carboxyl. Ob lub nitrogen atoms ntawm cov amino pawg muaj ib tug unshared electron khub nyob rau hauv txhua. EDTA yog hexadentate ligand. Tsis tas li ntawd, nws yog ib tug chelate tus neeg sawv cev vim muaj peev xwm mus sequester hlau ions. EDTA cov ntaub ntawv chelates nrog tag nrho cov cations tshwj tsis yog cov hlau alkali thiab cov chelates muaj qhov ruaj khov txaus. Qhov kev ruaj ntseg tshwm sim los ntawm ntau qhov chaw complexing nyob rau hauv lub molecule uas ua rau kom lub tawb zoo li cov qauv nyob ib ncig ntawm cov hlau ion. Qhov no cais cov hlau ion los ntawm cov kuab tshuaj molecules, yog li tiv thaiv kev daws teeb meem. Cov pab pawg carboxyl ntawm EDTA tuaj yeem sib cais pub dawb protons; Yog li ntawd, EDTA muaj acidic zog. Ntau hom EDTA yog luv li H₄Y, H₃Y^–, H. 2_Y2-^{, HY3}– ^{thiab Y}4- ^{pH qis (acidic nruab nrab), daim ntawv protonated ntawm EDTA (H} 4 _{Y) yog qhov tseem ceeb. Hauv qhov sib piv, ntawm pH siab (qhov nruab nrab nruab nrab), tag nrho daim ntawv deprotonated (Y} 4- ^{) predominates. Thiab raws li pH hloov pauv ntawm pH qis mus rau siab pH, lwm hom ntawv ntawm EDTA predominate nyob rau hauv tej yam pH qhov tseem ceeb. EDTA muaj nyob rau hauv daim ntawv protonated tag nrho los yog daim ntawv ntsev. Disodium EDTA thiab calcium disodium EDTA yog cov ntawv ntsev ntau tshaj plaws. Cov dawb acid H}4_{Y thiab dihydrate ntawm sodium ntsev Na}2_H2_Y.2H 2_{O yog kev lag luam muaj nyob rau hauv reagent zoo.}

Thaum yaj hauv dej, EDTA ua zoo li cov amino acid. Nws tshwm sim raws li ob lub zwitterion. Nyob rau hauv lub sijhawm no, tus nqi net yog xoom, thiab muaj plaub protons dissociable (ob protons yog txuam nrog carboxyl pawg thiab ob tug txuam nrog amine pawg). EDTA yog dav siv raws li ib tug complexometric titrant. Cov kev daws teeb meem ntawm EDTA yog ib qho tseem ceeb raws li ib tug titrant vim hais tias nws ua ke nrog hlau ions nyob rau hauv ib tug 1: 1 piv tsis hais tus nqi ntawm cov cation. EDTA kuj tseem siv los ua cov tshuaj tiv thaiv rau cov qauv lom neeg. Cov me me ntawm cov hlau ions tam sim no nyob rau hauv cov qauv lom neeg, thiab cov zaub mov tuaj yeem ua rau cov pa oxidation ntawm cov tebchaw uas muaj nyob hauv cov qauv. EDTA nruj nreem complexes cov hlau ions, yog li tiv thaiv lawv los ntawm catalyzing huab cua oxidation. Tias yog vim li cas nws tuaj yeem siv los ua cov khoom noj khoom haus.

EGTA

EGTA yog lub ntsiab lus luv rau ethylene glycol tetraacetic acid. Nws yog tus neeg sawv cev chelate, thiab zoo ib yam li EDTA. EGTA muaj ntau dua affinity rau calcium ions dua magnesium ions. EGTA muaj cov qauv hauv qab no.

Zoo ib yam li EDTA, EGTA kuj muaj plaub pawg carboxyl, uas tuaj yeem tsim plaub protons thaum sib cais. Muaj ob pawg amine thiab ob lub nitrogen atoms ntawm cov amino pawg muaj unshared electron khub hauv txhua. EGTA tuaj yeem siv los ua qhov tsis zoo kom zoo ib yam li pH ntawm lub cell nyob. Cov cuab yeej no ntawm EGTA tso cai rau nws siv hauv Tandem Affinity Purification, uas yog cov txheej txheem purification protein.

Dab tsi yog qhov txawv ntawm EDTA thiab EGTA?

• EDTA yog Ethylene diamine tetraacetic acid thiab EGTA yog ethylene glycol tetraacetic acid.

• EGTA muaj qhov hnyav dua molecular dua EDTA.

• Lwm yam tshaj li plaub pawg carboxyl, ob pawg amino, EGTA kuj tseem muaj ob lub pa oxygen atoms nrog cov electrons tsis sib koom.

• EGTA muaj affinity ntau dua rau calcium ions piv rau EDTA. Thiab EDTA muaj ntau dua affinity rau magnesium ions piv rau EGTA.

• EGTA muaj qhov kub siab tshaj EDTA.