Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/Profesor Albareda 1, E-18008 Granada, Spain.
Departamento de Botânica, Universidade de São Paulo, Brazil.
Nitric Oxide. 2017 Aug 1;68:51-55. doi: 10.1016/j.niox.2016.12.011. Epub 2016 Dec 27.
Pepper (Capsicum annuum L.) is an annual plant species of great agronomic importance whose fruits undergo major metabolic changes through development and ripening. These changes include emission of volatile organic compounds associated with respiration, destruction of chlorophylls and synthesis of new pigments (red/yellow carotenoids plus xanthophylls and anthocyans) responsible for color shift, protein degradation/synthesis and changes in total soluble reducing equivalents. Previous data have shown that, during the ripening of pepper fruit, an enhancement of protein tyrosine nitration takes place. On the other hand, it is well known that S-nitrosoglutathione reductase (GSNOR) activity can modulate the transnitrosylation equilibrium between GSNO and S-nitrosylated proteins and, consequently, regulate cellular NO homeostasis. In this study, GSNOR activity, protein content and gene expression were analyzed in green and red pepper fruits. The content of S-nitrosylated proteins on diaminofluorescein (DAF) gels was also studied. The data show that, while GSNOR activity and protein expression diminished during fruit ripening, S-nitrosylated protein content increased. Some of the protein candidates for S-nitrosylation identified, such as cytochorme c oxidase and peroxiredoxin II E, have previously been described as targets of this posttranslational modification in other plant species. These findings corroborate the important role played by GSNOR activity in the NO metabolism during the process of pepper fruit ripening.
辣椒（Capsicum annuum L.）是一种具有重要农业意义的一年生植物，其果实通过发育和成熟经历了重大的代谢变化。这些变化包括与呼吸相关的挥发性有机化合物的排放、叶绿素的破坏和新色素（红色/黄色类胡萝卜素加叶黄素和花色苷）的合成，这些色素导致颜色转变、蛋白质降解/合成以及总可溶性还原当量的变化。先前的数据表明，在辣椒果实成熟过程中，蛋白质酪氨酸硝化增强。另一方面，众所周知，S-亚硝基谷胱甘肽还原酶（GSNOR）的活性可以调节 GSNO 和 S-亚硝基化蛋白质之间的转亚硝基化平衡，从而调节细胞内的 NO 稳态。在这项研究中，分析了绿辣椒和红辣椒果实中的 GSNOR 活性、蛋白质含量和基因表达。还研究了二氨基荧光素（DAF）凝胶上 S-亚硝基化蛋白质的含量。数据表明，虽然 GSNOR 活性和蛋白质表达在果实成熟过程中降低，但 S-亚硝基化蛋白质含量增加。一些被鉴定为 S-亚硝基化的蛋白质候选物，如细胞色素 c 氧化酶和过氧化物酶 II E，以前在其他植物物种中已被描述为这种翻译后修饰的靶标。这些发现证实了 GSNOR 活性在辣椒果实成熟过程中对 NO 代谢的重要作用。
