title: On the formation of the mixed pyrrole catalysed by porphobilinogen synthase from Rhodobacter spheroides.
abstract: This enzyme porphobilinogen synthase (PBGS) catalyses the formation of porphobilinogen (PBG) from two molecules of 5-amino-levulinic acid (ALA). It has been claimed that the PBGS from Rhodobacter spheroides is able to form a mixed pyrrole, from one molecule of 5-aminolevulinic acid and one molecule of levulinic acid. The chemical synthesis of this mixed pyrrole allowed us to show that the compound formed from 5-aminolevulinic acid and levulinic acid with PBGS from R. spheroides has not the proposed structure. The putative enzyme-catalysed formation of the mixed pyrrole has been used as an argument for the postulated mechanism of PBGS. In view of our results, this line of argument has be re-evaluated.
authors.affiliation: Institut de Chimie, Université de Neuchatel, Switzerland.
authors.forename: R M
authors.initials: RM
authors.lastname: Lüönd
authors.forename: R
authors.initials: R
authors.lastname: Neier
mesh_terms: D000623:Porphobilinogen Synthase / Q000494:pharmacology*; D011758:Pyrroles / Q000138:chemical synthesis*; D012242:Rhodobacter sphaeroides / Q000201:enzymology*
chemical_list: D011758:Pyrroles; D000623:Porphobilinogen Synthase