Phosphoenolpyruvate carboxylase during grape berry development: protein level, enzyme activity and regulation
Phosphoenolpyruvate carboxylase during grape berry development: protein level, enzyme activity and regulation
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DOI：
10.1071/pp99141
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发表时间：
2000-03
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影响因子：
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通讯作者：
P. Diakou;L. Svanella;P. Raymond;J. Gaudillère;A. Moing
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文献类型：
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作者：
P. Diakou;L. Svanella;P. Raymond;J. Gaudillère;A. Moing
4.1.1.31以2个葡萄品种（葡萄属vinifera L.）品种，'赤霞珠'和'戈拉奇林'，浆果的正常和低有机酸含量分别。在大多数时期，低酸品种的蛋白质水平和体外活性高于正常酸品种。体内PEPC活性，使用14 CO2标记测量，是显着高于在低酸品种比正常酸品种约1周前和1周后veraison（这一天对应于开始成熟）。然而，分配到苹果酸是相同的两个品种。针对SorghumPEPC的N-末端部分产生的抗体识别葡萄浆果PEPC，表明参与PEPC调节的共识磷酸化位点的存在。通过研究对pH和苹果酸的敏感性来估计PEPC磷酸化状态。葡萄浆果PEPC出现更敏感的低pH值和苹果酸在成熟过程中（IC 50苹果酸，0.2-0.7毫米）相比，在早期的发展阶段（IC 50苹果酸，1.2-2毫米）的两个品种。因此，在正常酸的品种，PEPC似乎参与控制苹果酸的积累，但似乎并没有控制苹果酸浓度的差异，观察两个品种之间。
The protein level and regulation of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31, involved in malic acid synthesis) was studied during the fruit development of two grape (Vitis vinifera L.) varieties, ‘Cabernet Sauvignon’ and ‘Gora Chirine’, with berries of normal and low organic acid content, respectively. The protein level and in vitro activity were higher in the low-acid variety than in the normal-acid variety for most stages. In vivo PEPC activity, measured using 14 CO2 labelling, was significantly higher in the low-acid variety than in the normal-acid variety about 1 week before and 1 week after veraison (the day which corresponds to the onset of ripening). However, partitioning into malate was the same for both varieties. Antibodies raised against the N-terminal part of SorghumPEPC recognised the grape berry PEPC, indicating the presence of the consensus phosphorylation site involved in PEPC regulation. PEPC phosphorylation status was estimated by studying sensitivity to pH and malate. Grape berry PEPC appeared more sensitive to low pH and malate during ripening (IC50 malate, 0.2–0.7 mM) compared to during the earlier stages of development (IC50 malate, 1.2–2 mM) for both varieties. Therefore, in the normal-acid variety, PEPC seems to participate in controlling malic acid accumulation but does not seem to control the differences in malic acid concentration observed between the two varieties.