二磷酸腺苷又称腺苷二磷酸。一种高能磷酸化合物。二磷酸腺苷(ADP)是体内能量储存、代谢和信号转导的核心组成部分。它是ATP的前体,在此作用下,广泛应用于细胞过程,包括呼吸、生物合成反应、运动和细胞分裂。由二个磷酰基以焦磷酸键相连,再通过磷酸酯键与腺苷51-C连接而成。结构式如下图1。可水解产生腺苷一磷酸(AMP)和磷酸,反应的标准自由能变化为—27.2 kJ·mol-1。在生物体内,可由腺苷三磷酸(ATP)水解或磷酰基转移脱去一个磷酸后生成。在一般组织中又可经底物水平磷酸化和氧化磷酸化,在光合组织中还可经光合磷酸化,再转变为ATP。
图1为二磷酸腺苷结构式。
Human Endogenous Metabolite
Adenosine 5'-diphosphate consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine. Adenosine 5'-diphosphate is the product of ATP dephosphorylation by ATPases. ADP is converted back to ATP by ATP synthases. ATP is an important energy transfer molecule in cells. Adenosine 5'-diphosphate is utilized in a wide number of cellular processes, including respiration, biosynthetic reactions, motility, and cell division.