Search results
Results from the WOW.Com Content Network
Mycophenolate mofetil is an immunosuppressant drug used to prevent rejection in organ transplantation; it inhibits purine synthesis by blocking inosine monophosphate dehydrogenase (IMPDH). [5] Methotrexate also indirectly inhibits purine synthesis by blocking the metabolism of folic acid (it is an inhibitor of the dihydrofolate reductase).
In de novo generation of purines, the enzyme amidophosphoribosyltransferase acts upon PRPP to create phosphoribosylamine. [2] The histidine biosynthesis pathway involves the reaction between PRPP and ATP, which activates the latter to ring cleavage. Carbon atoms from ribose in PRPP form the linear chain and part of the imidazole ring in histidine.
In general, the water solubility of uric acid and its alkali metal and alkaline earth salts is rather low. All these salts exhibit greater solubility in hot water than cold, allowing for easy recrystallization. This low solubility is significant for the etiology of gout. The solubility of the acid and its salts in ethanol is very low or ...
The first committed step of purine biosynthesis starts from 5-phosphoribosyl 1 pyrophosphate. This undergoes a series of reactions to form IMP, an important branch point in the pathway. The pathway then branches to form adenylosuccinate and then adenylate (AMP) in one branch and xanthylate (XMP) and then guanylate (GMP) in the other branch.
Conversion of ribose 5-phosphate open chain form to furanose form. R5P is produced in the pentose phosphate pathway in all organisms. [2] The pentose phosphate pathway (PPP) is a metabolic pathway that runs parallel to glycolysis. It is a crucial source for NADPH generation for reductive biosynthesis [3] (e.g. fatty acid synthesis) and pentose ...
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex ...
Phosphagen system (ATP-PCr) and purine nucleotide cycle (PNC) [1] The Purine Nucleotide Cycle is a metabolic pathway in protein metabolism requiring the amino acids aspartate and glutamate. The cycle is used to regulate the levels of adenine nucleotides, in which ammonia and fumarate are generated. [2] AMP converts into IMP and the byproduct ...
Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines and their tautomers. They are the most widely occurring nitrogen-containing heterocycles in nature. [1]