Synthesis and Characterization of AMPS-HDB

NAD⁺ (crystallised lithium salt, ca. 100%), NADH (disodium salt, grade II, 98%), ADP (disodium salt, 98%) and crystalline bovine serum albumin (fraction V) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Molecular biology reagents were obtained from Invitrogen (Thermo Fisher Scientific, Waltham, MA, USA). The nucleotide analogue AMPS-HDB was synthesized as previously described by Vollmer et al., 1994 [38 (link)] for the 5′-O-[S-(4-bromo-2,3-dioxobutyl)]-thiophosphate. The replacement of the 4-bromo group by hydroxyl-group was achieved by incubation (5 h) in 0.03 M 2-(N-morpholino)ethanesulfonic acid (MES) buffer, pH 7.0 at 25 °C as previously described [38 (link)]. The structure was verified by electrospray tandem mass spectrometry (ESI/MS/MS) as described in [51 (link)].