Keefe A D, Newton G L, Miller S L
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla 92093.
Nature. 1995 Feb 23;373(6516):683-5. doi: 10.1038/373683a0.
The involvement of coenzyme A in many enzyme reactions suggests that it acted in this capacity very early in the development of life on Earth. Particularly relevant in this regard is its role in the activation of amino acids and hydroxy acids in the biosynthesis of some peptide antibiotics--a mechanism of peptide synthesis that forms the basis for the proposal that a thioester world could have preceded the RNA world. The components of coenzyme A have been shown to be probable prebiotic compounds: beta-alanine, pantoyl lactone and cysteamine and possibly adenosine. We show here that the pantetheine moiety of coenzyme A (which also occurs in a number of enzymes) can be synthesized in yields of several per cent by heating pantoyl lactone, beta-alanine and cysteamine at temperatures as low as 40 degrees C. These components are extremely soluble and so would have been preferentially concentrated in evaporating bodies of water, for example on beaches and at lagoon margins. Our results show that amide bonds can be formed at temperatures as low as 40 degrees C, and provide circumstantial support for the suggestion that pantetheine and coenzyme A were important in the earliest metabolic systems.
辅酶A参与许多酶促反应，这表明它在地球生命发展的早期就以这种功能发挥作用。在这方面特别相关的是它在某些肽抗生素生物合成中对氨基酸和羟基酸的激活作用——这种肽合成机制为硫酯世界可能先于RNA世界这一观点奠定了基础。辅酶A的成分已被证明可能是前体生物化合物：β-丙氨酸、泛酰内酯、半胱胺以及可能的腺苷。我们在此表明，通过在低至40摄氏度的温度下加热泛酰内酯、β-丙氨酸和半胱胺，辅酶A的泛酰巯基乙胺部分（也存在于多种酶中）能够以百分之几的产率合成。这些成分极易溶解，因此会优先在水体蒸发时浓缩，例如在海滩和泻湖边缘。我们的结果表明，酰胺键可以在低至40摄氏度的温度下形成，并为泛酰巯基乙胺和辅酶A在最早的代谢系统中很重要这一观点提供了间接支持。
