(S)-2-hydroxyglutarate + A => 2-oxoglutarate + AH2
(s)-2-hydroxyglutarate + a => 2-oxoglutarate + ah2
(S)-2-hydroxyglutarate + A => 2-oxoglutarate + AH2
(s)-2-hydroxyglutarate + a => 2-oxoglutarate + ah2