Chemoenzymatic synthesis of a series of 4-substituted glutamate analogues and pharmacological characterization at human glutamate transporters subtypes 1-3.
A series of nine L-2,4-syn-4-alkylglutamic acid analogues (1a-i) were synthesized in high yield and high enantiomeric excess (>99% ee) from their corresponding 4-substituted ketoglutaric acids (2a-i), using the enzyme aspartate aminotransferase (AAT) from pig heart or E. coli. The synthesized compounds were evaluated as potential ligands for the glutamate transporters EAAT1, EAAT2, and EAAT3 (excitatory amino acid transporter, subtypes 1-3) in the FLIPR membrane potential (FMP) assay. We found a distinct change in the pharmacological profile when the 4-methyl group (compound 1a, an EAAT1 substrate and EAAT2,3 inhibitor) was extended to a 4-ethyl group, compound 1b, as this analogue is an inhibitor at all three subtypes, EAAT1-3. Furthermore, we conclude that both large and bulky hydrophobic substituents in the 4-position of L-2,4-syn Glu are allowed by all three glutamate transporter subtypes EAAT1-3 while maintaining inhibitory activity.
Alaux
Sebastien
S
Département de Chimie, Université Blaise Pascal, 63177 Aubière Cedex, France.
Kusk
Mie
M
Sagot
Emanuelle
E
Bolte
Jean
J
Jensen
Anders A
AA
Bräuner-Osborne
Hans
H
Gefflaut
Thierry
T
Bunch
Lennart
L
D000818:Animals; D001219:Aspartate Aminotransferases / Q000138:chemical synthesis*; D002460:Cell Line; D027342:Excitatory Amino Acid Transporter 2 / Q000378:metabolism*; D050580:Excitatory Amino Acid Transporter 3 / Q000378:metabolism*; D005971:Glutamates / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007656:Ketoglutaric Acids / Q000737:chemistry; D008564:Membrane Potentials / Q000187:drug effects; D008958:Models, Molecular; D009206:Myocardium / Q000201:enzymology; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013552:Swine
D027342:Excitatory Amino Acid Transporter 2; D050580:Excitatory Amino Acid Transporter 3; D005971:Glutamates; D007656:Ketoglutaric Acids; D001219:Aspartate Aminotransferases