Hefetz A, Blum M S
Biochim Biophys Acta. 1978 Nov 1;543(4):484-96. doi: 10.1016/0304-4165(78)90303-3.
The biosynthesis of formic acid in the poison glands of formicine ants is closely related to the C-1 metabolism of the glandular cells. Experiments utilizing radiolabeled amino acids revealed that serine is a major precursor, contributing both its alpha and beta carbons to formic acids. 5,10[14C]methylene H4folate and 5,10[14C]methenyl H4folate also serve as precursors of formic acid in the poison gland, suggesting that they are intermediates in the pathway. Furthermore, these H4folate derivates were isolated from poison glands following incubation with [3-14C]serine and proved radioactive. The glandular cells are also exceptionally rich in the enzymes responsible for these reactions, supporting the proposed pathway. Although this pathway has been established in various organisms, the uniqueness of the poison gland system is that it accumulates formic acid to large extent, yet avoids its cytotoxicity. This is made possible by a combination of the biochemical characteristics of the pathway and the special morphological features of the poison gland.
蚁科蚂蚁毒腺中甲酸的生物合成与腺细胞的C-1代谢密切相关。利用放射性标记氨基酸进行的实验表明，丝氨酸是主要前体，其α和β碳原子都参与了甲酸的形成。5,10[¹⁴C]亚甲基四氢叶酸和5,10[¹⁴C]亚乙烯基四氢叶酸也是毒腺中甲酸的前体，这表明它们是该途径的中间产物。此外，在用[3-¹⁴C]丝氨酸孵育后，这些四氢叶酸衍生物从毒腺中分离出来并被证明具有放射性。腺细胞中还特别富含负责这些反应的酶，这支持了所提出的途径。尽管这条途径已在各种生物体中得到证实，但毒腺系统的独特之处在于它能大量积累甲酸，同时避免其细胞毒性。这是通过该途径的生化特性与毒腺特殊形态特征的结合实现的。
