Molecular and Biochemical Characterization of Olive 4-Hydroxyphenyl Pyruvate Dioxygenase Involved in the Biosynthesis of Tocopherols Present in Virgin Olive Oil.

Autor: Sánchez R; Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), 41013 Sevilla, Spain., Torres JE; Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), 41013 Sevilla, Spain., Vico LG; Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), 41013 Sevilla, Spain., Luaces P; Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), 41013 Sevilla, Spain., Sanz C; Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), 41013 Sevilla, Spain., Pérez AG; Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (CSIC), 41013 Sevilla, Spain.
Jazyk: angličtina
Zdroj: Journal of agricultural and food chemistry [J Agric Food Chem] 2024 Dec 25; Vol. 72 (51), pp. 28270-28279. Date of Electronic Publication: 2024 Dec 12.
DOI: 10.1021/acs.jafc.4c06657
Abstrakt: Olive ( Olea europaea ) fruit contains high amounts of tocopherols that are responsible, along with secoiridoid phenolic compounds, for most of the antioxidant and anti-inflammatory properties of virgin olive oil. This study focuses on the molecular and biochemical characterization of olive 4-hydroxyphenyl pyruvate dioxygenase (OeHPPD) catalyzing the biosynthesis of homogentisic acid, which constitutes the phenolic residue in the tocopherol molecule. OeHPPD is a cytoplasmic enzyme with a molecular weight of 49.8 kDa and a predicted tertiary structure very similar to the Arabidopsis enzyme that suggests similar catalytic mechanisms. OeHPPD has an estimated K cat of 75.26 s -1 and catalytic efficiency ( K m / K cat ) of 0.145 μM -1 s -1 with 4-hydroxyphenyl pyruvate as the substrate. The expression analysis in fruits from selected olive cultivars harvested at different ripening stages indicates that the Oe HPPD gene is temporally regulated and cultivar-dependent. Moreover, the analysis of OeHPPD expression in fruits affected by drought stress suggests that HPPD is involved in olive environmental adaptation.
Databáze: MEDLINE
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