High impact information on PPCDC

• Dfp proteins are bifunctional enzymes catalyzing the synthesis of 4'-phosphopantothenoylcysteine (CoaB activity) and its decarboxylation to 4'-phosphopantetheine (CoaC activity) [1].
• The proposed 4'-phosphopantothenoylcysteine binding clamp of the Methanocaldococcus CoaC activity differs significantly from those of other characterized CoaC proteins [1].
• The reactions catalyzed by orotidine monophosphate decarboxylase, oxalate decarboxylase, organomercurial lyase and phosphopantothenoylcysteine decarboxylase involve putative high-energy carbanion intermediates that cannot be stabilized by delocalization [2].
• This suggests that Cys(173) serves as an active site acid in the protonation of the enethiolate intermediate in PPC-DC enzymes [3].
• In this paper, we describe the characterization of the novel cyclopropyl-substituted product analogue 4'-phospho-N-(1-mercaptomethyl-cyclopropyl)-pantothenamide (PPanDeltaSH) as a mechanism-based inhibitor of the human PPC-DC enzyme [3].

Biological context of PPCDC

• In the case of PPC-DC enzymes the resulting enethiol is reduced to a thiol giving net decarboxylation of cysteine, while in EpiD and MrsD it is released as the final product of the reaction [3].

Associations of PPCDC with chemical compounds

• We propose that this protonation step is the key mechanistic difference between the oxidative decarboxylases EpiD and MrsD (which have either serine or threonine at the corresponding position in their active sites) and PPC-DC enzymes, which also reduce the intermediate in an overall simple decarboxylation reaction [3].

Analytical, diagnostic and therapeutic context of PPCDC

• METHODS: This prospective study included 22 patients (27 eyes) with uncontrolled COAC on medical treatment undergoing punch trabeculectomy through a scleral tunnel [4].

References