Dehydrogenase semialdehyde

Succinic semialdehyde (SSA) is synthesized in the mitochondria through transamination of y-aminobutyric acid (GABA) by GABA transaminase (GABA-T). Most of the SSA is oxidized by SSA dehydrogenase (SSA-DH) to form succinate, which is used for energy metabolism and results in the end products CO2 + H2O, which are expired. A small portion of SSA (<2%) is converted by SSA reductase (SSA-R) in the cytosol to GHB. GHB may also be oxidized back to SSA by GHB dehydrogenase (GHB-DH). 

Proline. Prohne forms dehydroprohne, glutamate-y-semialdehyde, glutamate, and, ultimately, a-ketoglu-tarate (Figure 30—3, top). The metabohc block in type I kyperprolinemia is at proline dehydrogenase. 

Gescher J, W Ismail, E Olgeschlager, W Eisenreich, J Wort, G Fuchs (2006) Aerobic benzoyl-coenzyme A (Co A) catabolic pathway in Azoarcus evansii conversion of ring cleavage product by 3,4-dehydroadipyl-CoA semialdehyde dehydrogenase. J Bacterial 188 2919-2927. 

Disorders of GABA Vitamin B6-dependent seizures Often an absence of succinic semialdehyde dehydrogenase Hypotonia, ataxia, mental retardation in older child. Increased urine 4-OH-butyric acid. Pyridoxine (B6-dependent disorder) Inhibitors of GABA transaminase... 

Succinic semialdehyde dehydrogenase deficiency. Patients have mental retardation, cerebellar disease, and hypotonia. They excrete large amounts of both succinic semialdehyde and 4-hydroxybutyric acid. There is no known therapy. 

Gupta, M Greven, R., Jansen, E. E., et al. (2002) Therapeutic intervention in mice deficient for succinate semialdehyde dehydrogenase (gamma-hydroxybutyric aciduria). J. Pharmacol. Exp. Ther. 302,180-187. 

This enzyme [EC 1.2.1.38], also known as A-acetylgluta-mate semialdehyde dehydrogenase and NAGSA dehydrogenase, catalyzes the reaction of A-acetylglutamate 5-semialdehyde with NADP+ and phosphate to generate A-acetyl-5-glutamyl phosphate and NADPH. 

Aspartate kinase [EC 2.T.2.4], also known as asparto-kinase, catalyzes the reaction of aspartate with ATP to produce 4-phosphoaspartate and ADP. The enzyme isolated from E. coli is a multifunctional protein, also exhibiting the ability to catalyze the reaction of homoserine with NAD(P) to produce aspartate 4-semialdehyde and NAD(P)H (that is, the activity of homoserine dehydrogenase, EC 1.1.1.3). 

METHYLENETETRAHYDROFOLATE DEHYDROGENASE METHYLMALO-NATE-SEMIALDEHYDE DEHYDROGENASE... 

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