Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China.
Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China.
Methods Enzymol. 2022;662:227-240. doi: 10.1016/bs.mie.2021.10.022. Epub 2021 Dec 7.
Selenocysteine (Sec, U) is the 21st amino acid, and proteins with selenocysteine are defined as selenoproteins. The currently known selenoproteins are all featured by the presence of selenocysteine insertion sequence (SECIS) on their mRNA, and SECIS plays an essential role in the selenocysteine insertion mechanism. However, due to the extremely low occurrences of selenoproteins in a whole proteome (e.g., only 25 selenoproteins in the human proteome) and the low sequence conservation of SECIS, analysis of selenoproteins and discovery of new selenoproteins exclusively on SECIS are intrinsically challenging. To this end, the selenocysteine-specific mass spectrometry (SecMS) and SECIS-independent selenoprotein (SIS) database are developed, showing abilities to profile whole selenoproteomes sensitively and to discover potential new selenoproteins. Here, we detail the SecMS strategy and propose it will advance the exploration for new selenoproteins and functional studies of selenoproteins.
硒代半胱氨酸（Sec，U）是第 21 种氨基酸，含有硒代半胱氨酸的蛋白质被定义为硒蛋白。目前已知的硒蛋白都在其 mRNA 上具有硒代半胱氨酸插入序列（SECIS），SECIS 在硒代半胱氨酸插入机制中起着至关重要的作用。然而，由于硒蛋白在整个蛋白质组中的出现频率极低（例如，人类蛋白质组中只有 25 种硒蛋白），以及 SECIS 的低序列保守性，专门基于 SECIS 对硒蛋白进行分析和发现新的硒蛋白在本质上具有挑战性。为此，开发了硒代半胱氨酸特异性质谱（SecMS）和 SECIS 非依赖性硒蛋白（SIS）数据库，展示了灵敏地描绘整个硒蛋白组和发现潜在新硒蛋白的能力。在这里，我们详细介绍了 SecMS 策略，并提出它将推进对新硒蛋白的探索和对硒蛋白的功能研究。
