Determination of the dissociation constants of pea diamine oxidase
Jazyk angličtina Země Austrálie Médium print
Typ dokumentu časopisecké články
PubMed
1616501
Knihovny.cz E-zdroje
- MeSH
- Fabaceae enzymologie MeSH
- histaminasa chemie metabolismus MeSH
- histidin metabolismus MeSH
- játra enzymologie MeSH
- katalasa metabolismus MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- léčivé rostliny * MeSH
- vazebná místa MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- histaminasa MeSH
- histidin MeSH
- katalasa MeSH
The activity of diamine oxidase [EC 1.4.3.6] (DAO) isolated from pea cotyledons was measured in Britton-Robinson buffers at pH range 5.0-9.6 by spectrophotometric method with E-1,4-diamino-2-butene as substrate. The enzyme has the highest activity at pH = 7.7 and in pH greater than 8.0 it is irreversible denaturated with time. The dissociation constants of the enzyme and enzyme-substrate complex were calculated by Dixon's method from plots of log Vmax, log KM and log Vmax/KM against pH. The pKEA = 6.5 suggests that histidine is in active site of DAO.
