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Acetamidopropanal is associated with urea cycle and metabolism of arginine, proline, glutamate, aspartate and asparagine. Induction of SSAT typically gives rise to growth inhibition or apoptosis, depending upon the cell type and the extent of enzyme overexpression. In such experiments, growth inhibition has been closely linked to depletion of intracellular polyamine pools ( 12) and disturbances in polyamine metabolism ( 13), whereas apoptosis has been associated with downstream events emanating from polyamine oxidase-mediated oxidation of acetylated polyamines and the associated release of oxidatively reactive by-products such as hydrogen peroxide and the aldehyde, 3-acetamidopropanal.

D-proline is an isomer of the naturally occurring amino acid, L-Proline. D-amino acids have been found in relatively high abundance in human plasma and saliva (PMID: 16480744). These amino acids may be of bacterial origin, but there is also evidence that they are endogenously produced through amino acid racemase activity (PMID: 1426150).

Proline (Pro), also known as L-proline is an alpha-amino acid. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). Amino acids are organic compounds that contain amino (–NH2) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid. Proline is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Proline is found in all organisms ranging from bacteria to plants to animals. It is classified as an aliphatic, non-polar amino acid. Proline is sometimes called an imino acid, although the IUPAC definition of an imine requires a carbon-nitrogen double bond. Proline is a non-essential amino acid that is synthesized from glutamic acid. It is an essential component of collagen and is important for proper functioning of joints and tendons. Proline is derived from the amino acid L-glutamate in which glutamate-5-semialdehyde is first formed by glutamate 5-kinase and glutamate-5-semialdehyde dehydrogenase (which requires NADH or NADPH). This semialdehyde can then either spontaneously cyclize to form 1-pyrroline-5-carboxylic acid, which is reduced to proline by pyrroline-5-carboxylate reductase, or turned into ornithine by ornithine aminotransferase, followed by cyclization by ornithine cyclodeaminase to form proline. L-Proline has been found to act as a weak agonist of the glycine receptor and of both NMDA and non-NMDA ionotropic glutamate receptors. It has been proposed to be a potential endogenous excitotoxin/neurotoxin. Studies in rats have shown that when injected into the brain, proline non-selectively destroys pyramidal and granule cells (PMID: 3409032 ). Therefore, under certain conditions proline can act as a neurotoxin and a metabotoxin. A neurotoxin causes damage to nerve cells and nerve tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of proline are associated with at least five inborn errors of metabolism, including hyperprolinemia type I, hyperprolinemia type II, iminoglycinuria, prolinemia type II, and pyruvate carboxylase deficiency. People with hyperprolinemia type I often do not show any symptoms even though they have proline levels in their blood between 3 and 10 times the normal level. Some individuals with hyperprolinemia type I exhibit seizures, intellectual disability, or other neurological or psychiatric problems. Hyperprolinemia type II results in proline levels in the blood between 10 and 15 times higher than normal, and high levels of a related compound called pyrroline-5-carboxylate. Hyperprolinemia type II has signs and symptoms that vary in severity and is more likely than type I to involve seizures or intellectual disability.

An alpha-amino acid that is pyrrolidine bearing a carboxy substituent at position 2." []

4-Amino-2-methylenebutanoic acid is found in nuts. 4-Amino-2-methylenebutanoic acid is found in Arachis hypogaea (peanut

Pterolactam is found in green vegetables. Pterolactam is a constituent of Pteridium aquilinum (bracken fern).

DL-Allylglycine is an alpha-amino acid. An inhibitor of glutamate decarboxylase and an antagonist of GAMMA-AMINOBUTYRIC ACID. It is used to induce convulsions in experimental animals.

An L-alpha-amino acid residue that is L-threonine residue in which the hydroxy group of the side chain is replaced by a methoxy group. It is a post-translational modification that occurs in thiocillin antibiotics." []

An L-valine residue that is substituted by a hydroxy group at position 3." []

A D-valine residue that is substituted by a hydroxy group at position 4." []

A D-valine residue that is substituted by a hydroxy group at position 3. A post-translational modification occurring on several Val residues in polytheonamides." []

A non-proteinogenic alpha-amino acid that is 1-aminocyclopropanecarboxylic acid carrying an additional methyl substituent at position 2 on the cyclopropane ring." []

1-AMINOCYCLOBUTANE CARBOXYLIC ACID is a L-alpha-amino acid.