In molecular biology, biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism.
N-Acetylglutamic acid (also referred to as N-acetylglutamate, abbreviated NAG, chemical formula C7H11NO5) is biosynthesized from glutamate and acetylornithine by ornithine acetyltransferase, and from glutamic acid and acetyl-CoA by the enzyme N-acetylglutamate synthase. The reverse reaction, hydrolysis of the acetyl group, is catalyzed by a specific hydrolase. It is the first intermediate involved in the biosynthesis of arginine in prokaryotes and simple eukaryotes and a regulator in the process known as the urea cycle that converts toxic ammonia to urea for excretion from the body in vertebrates.
In enzymology, a shikimate dehydrogenase (EC 1.1.1.25) is an enzyme that catalyzes the chemical reaction
In enzymology, a succinylglutamate-semialdehyde dehydrogenase (EC 1.2.1.71) is an enzyme that catalyzes the chemical reaction
In enzymology, a phosphogluconate dehydrogenase (decarboxylating) (EC 1.1.1.44) is an enzyme that catalyzes the chemical reaction
In enzymology, an acyl-CoA dehydrogenase (NADP+) (EC 1.3.1.8) is an enzyme that catalyzes the chemical reaction
In enzymology, an enoyl-[acyl-carrier-protein] reductase (NADPH, B-specific) (EC 1.3.1.10) is an enzyme that catalyzes the chemical reaction
In enzymology, an aspartate-semialdehyde dehydrogenase is an enzyme that is very important in the biosynthesis of amino acids in prokaryotes, fungi, and some higher plants. It forms an early branch point in the metabolic pathway forming lysine, methionine, leucine and isoleucine from aspartate. This pathway also produces diaminopimelate which plays an essential role in bacterial cell wall formation. There is particular interest in ASADH as disabling this enzyme proves fatal to the organism giving rise to the possibility of a new class of antibiotics, fungicides, and herbicides aimed at inhibiting it.
In enzymology, a glutamate-5-semialdehyde dehydrogenase (EC 1.2.1.41) is an enzyme that catalyzes the chemical reaction
A glutamyl-tRNA reductase (EC 1.2.1.70) is an enzyme that catalyzes the chemical reaction
In enzymology, an FMN reductase (EC 1.5.1.29) is an enzyme that catalyzes the chemical reaction
In enzymology, a glutamate synthase (NADPH) (EC 1.4.1.13) is an enzyme that catalyzes the chemical reaction
In enzymology, a NAD(P)H dehydrogenase (quinone) (EC 1.6.5.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a saccharopine dehydrogenase (NADP+, L-glutamate-forming) (EC 1.5.1.10) is an enzyme that catalyzes the chemical reaction
In enzymology, a saccharopine dehydrogenase (NADP+, L-lysine-forming) (EC 1.5.1.8) is an enzyme that catalyzes the chemical reaction
In enzymology, an acetylornithine transaminase (EC 2.6.1.11) is an enzyme that catalyzes the chemical reaction
In enzymology, an acetylglutamate kinase is an enzyme that catalyzes the chemical reaction:
Delta-1-pyrroline-5-carboxylate synthetase (P5CS) is an enzyme that in humans is encoded by the ALDH18A1 gene. This gene is a member of the aldehyde dehydrogenase family and encodes a bifunctional ATP- and NADPH-dependent mitochondrial enzyme with both gamma-glutamyl kinase and gamma-glutamyl phosphate reductase activities. The encoded protein catalyzes the reduction of glutamate to delta1-pyrroline-5-carboxylate, a critical step in the de novo biosynthesis of proline, ornithine and arginine. Mutations in this gene lead to hyperammonemia, hypoornithinemia, hypocitrullinemia, hypoargininemia and hypoprolinemia and may be associated with neurodegeneration, cataracts and connective tissue diseases. Alternatively spliced transcript variants, encoding different isoforms, have been described for this gene. As reported by Bruno Reversade and colleagues, ALDH18A1 deficiency or dominant-negative mutations in P5CS in humans causes a progeroid disease known as De Barsy Syndrome.
Succinate-semialdehyde dehydrogenase (NADP+) (EC 1.2.1.79, succinic semialdehyde dehydrogenase (NADP+), succinyl semialdehyde dehydrogenase (NADP+), succinate semialdehyde:NADP+ oxidoreductase, NADP-dependent succinate-semialdehyde dehydrogenase, GabD) is an enzyme with systematic name succinate-semialdehyde:NADP+ oxidoreductase. This enzyme catalyses the following chemical reaction
Glutamate-5-semialdehyde is a non-proteinogenic amino acid involved in both the biosynthesis and degradation of proline and arginine, as well as in the biosynthesis of antibiotics, such as carbapenems. It is synthesized by the reduction of glutamyl-5-phosphate by glutamate-5-semialdehyde dehydrogenase.
