Flodgaard H, Klenow H
Biochem J. 1982 Dec 15;208(3):737-42. doi: 10.1042/bj2080737.
Diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) may be formed in the back reaction of the amino acid-activation reaction [Zamecnik, Stephenson, Janeway & Randerath (1966) Biochem. Biophys. Res. Commun. 24, 91-98]. On the basis of a number of observations of the properties of Ap4A it has been suggested that it may have a signal function for the initiation of DNA replication in eukaryotic cells] Grummt (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 371-375]. In the present paper human platelets have been shown to contain relatively large amounts of Ap4A. The compound is apparently metabolic inactive in platelets, but it is almost quantitatively released when platelets are activated to aggregate by treatment with thrombin. The results are discussed in connection with the known growth-stimulating activity of platelets.
5',5''-P1,P4-四磷酸二腺苷（Ap4A）可能在氨基酸活化反应的逆反应中形成[扎梅尼克、斯蒂芬森、詹韦和兰德拉斯（1966年），《生物化学与生物物理学研究通讯》24卷，91 - 98页]。基于对Ap4A性质的一些观察结果，有人提出它可能对真核细胞中DNA复制的起始具有信号功能[格鲁姆特（1978年），《美国国家科学院院刊》75卷，371 - 375页]。在本文中，已证明人类血小板含有相对大量的Ap4A。该化合物在血小板中显然无代谢活性，但当用凝血酶处理使血小板活化聚集时，它几乎能被定量释放。结合血小板已知的生长刺激活性对这些结果进行了讨论。
