4335 SAICAR SAICAR (or (S)-2-[5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamido]succinate) is a substrate for the multifunctional protein ADE2. SAICAR is an intermediate in purine metabolism. SAICAR is converted from 5-amino-1-(5-phospho-D-ribosyl) imidazole-4-carboxylate via phosphoribosylaminoimidazole-succinocarboxamide synthase (EC: 6.3.2.6) or SAICAR synthase. This enzyme catalyses the seventh step out of ten in the biosynthesis of purine nucleotides. The appearance of succinylaminoimidazolecarboxamide riboside (SAICAriboside) and succinyladenosine (S-Ado) in cerebrospinal fluid, in urine, and, to a lesser extent, in plasma is characteristic of a heritable deficiency known as adenylosuccinate lyase deficiency. Adenylosuccinate lyase deficiency is responsible for a range of symptoms that involve psychomotor retardation, often accompanied by epileptic seizures, and autistic features. When present in sufficiently high levels, SAICAR can act as an oncometabolite, a metabotoxin, and an acidogen. An oncometabolite is a compound that promotes tumour growth and survival. An acidogen is an acidic compound that induces acidosis, which has multiple adverse effects on many organ systems. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. As an oncometabolite, high levels of SAICAR stimulate pyruvate kinase isoform M2 and promote cancer cell survival in glucose-limited conditions such as aerobic glycolysis (PMID: 23086999). As an organic acid, SAICAR is associated with acidosis. Abnormally high levels of organic acids in the blood (organic acidemia), urine (organic aciduria), the brain, and other tissues lead to general metabolic acidosis. Acidosis typically occurs when arterial pH falls below 7.35. In infants with acidosis, the initial symptoms include poor feeding, vomiting, loss of appetite, weak muscle tone (hypotonia), and lack of energy (lethargy). These can progress to heart, liver, and kidney abnormalities, seizures, coma, and possibly death. These are also the characteristic symptoms of untreated adenylosuccinate lyase deficiency. Many affected children with organic acidemias experience intellectual disability or delayed development. 3031-95-6 160666 C13H19N4O12P White powder. No indication of carcinogenicity to humans (not listed by IARC). This is an endogenously produced metabolite found in the human body. It is used in metabolic reactions, catabolic reactions or waste generation. Chronically high levels of SAICAR are associated with Adenylosuccinate Lyase Deficiency. 2014-08-29T06:13:39Z 2018-03-21T17:46:15Z C04823 18319 P-RIBOSYL-4-SUCCCARB-AMINOIMIDAZOLE true [H][C@@](CC(O)=O)(N=C(O)C1=C(N)N(C=N1)[C@]1([H])O[C@]([H])(COP(O)(O)=O)[C@@]([H])(O)[C@@]1([H])O)C(O)=O C13H19N4O12P InChI=1S/C13H19N4O12P/c14-10-7(11(22)16-4(13(23)24)1-6(18)19)15-3-17(10)12-9(21)8(20)5(29-12)2-28-30(25,26)27/h3-5,8-9,12,20-21H,1-2,14H2,(H,16,22)(H,18,19)(H,23,24)(H2,25,26,27)/t4-,5+,8+,9+,12+/m0/s1 InChIKey=NAQGHJTUZRHGAC-ZZZDFHIKSA-N 454.2833 454.073708604 Endogenous Solid HMDB00797 141175 Shaw, Gordon; Thomas, Peter S.; Patey, Carole A. H.; Thomas, Susan E. Purines, pyrimidines and imidazoles. Part 50. Inhibition of adenylosuccinate AMP-lyase no. 4.3.2.2. by derivatives of N-(5-amino-1-b-D-ribofuranosylimidazole-4-carbonyl)-L-aspartic acid 5'-phosphate (SAICAR) and virazole 5'-phosphate. Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) (1979), (6), 1415-24.