Purification and Kinetic Characterization of an Anionic Peroxidase from Melon (Cucumis melo L.) Cultivated under Different Salinity Conditions
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- 作者：Jose Neptuno Rodrí ; guez-Ló ; pez ; Juan Carlos Espí ; n ; Francisco del Amor ; José ; Tudela ; Vicente Martí ; nez ; Antonio Cerdá ; and Francisco Garcí ; a-Cá ; novas
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2000
- 出版时间：May 2000
- 年：2000
- 卷：48
- 期：5
- 页码：1537 - 1541
- 全文大小：64K
- 年卷期：v.48,no.5(May 2000)
- ISSN：1520-5118
文摘
The partial characterization of an anionic peroxidase in melon fruit is described. Four melonperoxidase (MPX) isoenzymes were detected in crude extracts after isoelectric focusing. The majorMPX isoenzyme (pI = 3.7) was partially purified by including hydrophobic and anion-exchangechromatography in the purification scheme. The sample obtained was used to characterize MPX.This peroxidase did not show activity on ascorbic acid but oxidized guaiacol at a high rate, showingan optimum pH of 5.5 when acting on this last reducing substrate. Melon fruits grown under highlysaline conditions showed slightly increased levels of this anionic isoenzyme. Kinetic studies using2,2'-azinobis(3-ethylbenzothiazolinesulfonic acid) (ABTS) as reducing substrate showed that increasedsalinity in the growth medium did not modify the kinetic parameters of melon peroxidase on bothhydrogen peroxide and reducing substrate.Keywords: Melon; peroxidase; salinity; peroxidase isoenzyme; enzyme kinetics.