Enzymatic synthesis of S-aminoethyl-L-cysteine from pantetheine.
The recently characterized compound S-aminoethylcysteine ketimine can be synthesized from purified S-aminoethylcysteine by enzymatic systems (transaminases or L-amino acid oxidase) present in mammalian tissues. S-Aminoethylcysteine, which could be considered as the natural precursor of the ketimine, is produced from L-serine and cysteamine by the action of the enzyme cystathionine-beta-synthase. We demonstrate in this paper that pantetheine, a normal cellular component, is an efficient cysteamine donor for the synthesis of S-aminoethylcysteine and of S-aminoethylcysteine ketimine in the place of free cysteamine, and we describe the enzymatic system, composed of partially purified enzymes, for the in vitro synthesis of S-aminoethylcysteine ketimine from pantetheine. This seems to indicate a new biological role for pantetheine.
Pitari
G
G
Dipartimento di Scienze e Tecnologie Biomediche e di Biometria, Università de L'Aquila, Italy.
Maurizi
G
G
Flati
V
V
Ursini
C L
CL
Spera
L
L
Duprè
S
S
Cavallini
D
D
D000581:Amidohydrolases / Q000378:metabolism; D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000603:Amino Acids, Sulfur / Q000096:biosynthesis* / Q000138:chemical synthesis; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D003543:Cysteamine / Q000378:metabolism; D003545:Cysteine / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000138:chemical synthesis; D058851:GPI-Linked Proteins; D050830:L-Amino Acid Oxidase; D010204:Pantetheine / Q000378:metabolism*; D012694:Serine / Q000378:metabolism
D000603:Amino Acids, Sulfur; D058851:GPI-Linked Proteins; C000204:S-2-aminoethyl cysteine; D012694:Serine; D010204:Pantetheine; D003543:Cysteamine; C035497:thialysine ketimine; D000594:Amino Acid Oxidoreductases; D050830:L-Amino Acid Oxidase; D000581:Amidohydrolases; C022314:pantetheinase; D003541:Cystathionine beta-Synthase; D003545:Cysteine