“…The enzyme catalyzes a nucleophilic attack of the anomeric oxygen of b-Neu5Ac on the a-phosphate of CTP [19] and requires Mg 2+ or Mn 2+ for activity. [17,20] So far, enzymatic procedures for the synthesis of 2 (Equation 1) have been developed to routine application, [21,22,23,24,25,26,27,28] however, these are not generally amenable to the preparative nucleotide activation of modified sialic acids or their structural analogs because of the narrow substrate specificity of known CMP-sialate synthetases, and an often poor access to larger protein quantities. [25,29] CMP-sialate synthetases have been isolated from various eukaryotic and prokaryotic sources.…”