- Tytuł:
- Polyphenol oxidase from wheat bran is a serpin
- Autorzy:
-
Yamasaki, Yoshiki
Konno, Haruyoshi
Noda, Kazuhiko - Powiązania:
- https://bibliotekanauki.pl/articles/1040750.pdf
- Data publikacji:
- 2008
- Wydawca:
- Polskie Towarzystwo Biochemiczne
- Tematy:
-
polyphenol oxidase
serpin
wheat bran - Opis:
- Polyphenol oxidase (PPO; EC 1.10.3.2) was isolated from wheat bran by a procedure that included ammonium sulfate fractionation, batch adsorption by DEAE-cellulofine, CM-cellulofine column chromatography, DEAE-cellulofine column chromatography, preparative isoelectric focusing, adsorption on the membrane of a Vivapure Q Maxi H spin column, and heat treatment. These procedures led to 150-fold purification with 4.2% recovery. The PPO was homogeneous by SDS/PAGE. The relative molecular weight of the PPO was estimated to be 37000 based on its mobility in SDS/PAGE. The isoelectric point of the PPO was 4.4. The Km values of the PPO for caffeic acid, chlorogenic acid, pyrocatechol, 4-methyl catechol and l-DOPA as substrates were 0.077, 0.198, 1.176, 1.667 and 4.545 mM. The PPO was strongly inhibited by tropolone. The Ki value for tropolone is 2.2 × 10-7 M. The sequence of the 15 N-terminal amino-acid residues was determined to be ATDVRLSIAHQTRFA, which was identical to those of serpin from Triticum aestivum and protein Z from Hordeum vulgare. The PPO strongly inhibited the activity of trypsin, which is an enzyme of serine proteases; 50% inhibition was observed with 1.5 × 10-7 M PPO. The Ki value for PPO is 2.3 × 10-8 M. The wheat bran PPO should be a very important protein for protecting wheat against disease, virus, insect and herbivore damages by both the activities of PPO and protease inhibitor.
- Źródło:
-
Acta Biochimica Polonica; 2008, 55, 2; 325-328
0001-527X - Pojawia się w:
- Acta Biochimica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł