RESUMO
We describe an efficient and scalable procedure for the chemical synthesis of nucleoside 5'-phosphosulfates (NPS) from nucleoside 5'-phosphorimidazolides and sulfate bis(tributylammonium) salt. Using this method we obtained various NPS with yields ranging from 70-90%, including adenosine 5'-phosphosulfate (APS) and 2',3'-cyclic precursor of 3'-phosphoadenosine 5'-phosphosulfate (PAPS), which are the key intermediates in the assimilation and metabolism of sulfur in all living organisms.
Assuntos
Adenosina Fosfossulfato/química , Nucleosídeos/química , Fosfoadenosina Fosfossulfato/química , Adenosina Fosfossulfato/síntese química , Fator de Iniciação 4E em Eucariotos/metabolismo , Ligação ProteicaRESUMO
Initial activation of inorganic sulfate for subsequent synthesis of sulfated biomolecules requires the action of ATP-sulfurylase to generate adenosine 5'-phosphosulfate (APS). This activated sulfate intermediate is both chemically labile and susceptible to enzymatic degradation. Consequently, it has not proven useful as a ligand for either purification or characterization of the various APS-utilizing enzymes. For these purposes, a stable analog of APS was required. This paper describes the simple and efficient synthesis and structural confirmation of a nonhydrolyzable APS analog, beta-methylene APS, with an overall molar yield of 40-50%. The method involves nucleophilic substitution of the chlorine moiety of a 5'-chloromethylphosphonate ester of 2',3'-O-isopropylidene adenosine by a sulfite ion. We also report the initial utilization of this compound as an inhibitor in kinetic trials of both ATP-sulfurylase and APS kinase and as an affinity ligand for the purification of these two APS-utilizing enzymes from cartilaginous tissue.