title: Threonine aldolases-screening, properties and applications in the synthesis of non-proteinogenic beta-hydroxy-alpha-amino acids.
abstract: Threonine aldolases (TAs) constitute a powerful tool for catalyzing carbon-carbon bond formations in synthetic organic chemistry, thus enabling an enantio- and diastereoselective synthesis of beta-hydroxy-alpha-amino acids. Starting from the achiral precursors glycine and an aldehyde, two new stereogenic centres are formed in this catalytic step. The resulting chiral beta-hydroxy-alpha-amino acid products are important precursors for pharmaceuticals such as thiamphenicol, a L: -threo-phenylserine derivative or L: -threo-3,4-dihydroxyphenylserine. TAs are pyridoxal-5-phosphate-dependent enzymes, which, in nature, catalyze the cleavage of L: -threonine or L: -allo-threonine to glycine and acetaldehyde in a glycine biosynthetic pathway. TAs from a broad number of species of bacteria and fungi have been isolated and characterised as biocatalysts for the synthesis of beta-hydroxy-alpha-amino acids. In this review, screening methods to obtain novel TAs, their biological function, biochemical characterisation and preparative biotransformations with TAs are described.
authors.affiliation: evocatal GmbH, Düsseldorf, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Dückers
authors.forename: Katrin
authors.initials: K
authors.lastname: Baer
authors.forename: Sabine
authors.initials: S
authors.lastname: Simon
authors.forename: Harald
authors.initials: H
authors.lastname: Gröger
authors.forename: Werner
authors.initials: W
authors.lastname: Hummel
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D000596:Amino Acids / Q000096:biosynthesis / Q000138:chemical synthesis* / Q000737:chemistry; D005998:Glycine / Q000378:metabolism; D012696:Glycine Hydroxymethyltransferase / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification*; D007700:Kinetics; D011994:Recombinant Proteins / Q000096:biosynthesis; D013912:Threonine / Q000378:metabolism
chemical_list: D000447:Aldehydes; D000596:Amino Acids; D011994:Recombinant Proteins; D013912:Threonine; D012696:Glycine Hydroxymethyltransferase; D005998:Glycine