Nucleoside phosphorylation by the mineral schreibersite

Abstract

Phosphorylation of the nucleosides adenosine and uridine by the simple mixing and mild heating of aqueous solutions of the organic compounds with synthetic analogs of the meteoritic mineral schreibersite, (Fe,Ni)3P under slightly basic conditions (pH ~9) is reported. These results suggest a potential role for meteoritic phosphorus in the origin and development of early life.

Figure 1. UPLC-MS extracted ion chromatograms at m/z = 346.05 ± 0.06, corresponding to adenosine monophosphate [M-H]⁻ ionic species in both a mixture of standards, and in samples Ad1-Ad5.

Experimental conditions for Ad1-Ad5 are given in Table 1, and consist of mixtures of adenosine and iron phosphide with other solutes in water, heated to 80 °C. Uridine data may be found in the SI. (a) 5′, 3′ and, 2′ AMP standards (50 μM); (b) reaction Ad1; (c) reaction Ad2; (d) reaction Ad3 (e) reaction Ad4 (f) reaction Ad5.

Figure 2. Tandem MS (MS/MS) fragmentation spectra for 5′, 3′, and 2′ adenosine monophosphate standards and corresponding retention-time matched chromatographic peaks in sample Ad4.

A collision energy of 15 eV was used. The precursor ion selected in all cases was m/z 346.05. Fragmentation spectra for other reaction mixtures may be found in the SI. (a) 50 μM 5′AMP standard (R.T. = 6.06 min); (b) 50 μM 3′AMP standard (R.T. = 6.75 min); (c) 50 μM 2′ AMP standard (R.T. = 7.09 min); (d) reaction Ad4 5′AMP (R.T. = 6.11 min); (e) reaction Ad4 3′AMP (R.T. = 6.80 min); (f) reaction Ad4 2′AMP (R.T. = 7.14 min).

Figure 3. ³¹P NMR spectrum of reaction mixture resulting from mixing adenosine with Fe₃P (equivalent to sample Ad3, but with an additional substrate, FeS; FeS was not found to influence these results).

Peaks are identified based on peak position vs. standards, and from J-coupling constants (~5 Hz for 3 bond H-P interactions). The doublets are CH-O-P interactions, and the triplet is a CH₂-O-P interaction. Species identification was confirmed by spiking with an adenosine monophosphate standard, causing the triplet to increase in signal strength. The peak at 5.1 corresponds to phosphite (HPO₃²⁻), and the peak at 5.6 is orthophosphate (HPO₄²⁻). Both compounds are common products during phosphide corrosion, and a majority of the total dissolved P is in these two species.