Inosine 5 -monophosphate, structures

The purine bases, adenine and guanine, participate in nature by providing structural elements of nucleic acids and numerous cofactors. The deaminated products of adenine and guanine do not participate in these coenzymic functions except in a relatively few instances. For example, the relative ineffectiveness of inosine monophosphate (IMP) vs. 

JT Beck, S Zhao, CC Wang. Cloning, sequencing, and structural analysis of the DNA encoding inosine monophosphate dehydrogenase (EC 1.1.1.205) from Tritrichomonas foetus. Exp Parasitol 78 101-112, 1994. 

The main task of several early investigations was to confirm the Pt-N(7) bonding model. One of the first reported structures was that of the 1 2 complex of a ds-(NH3)2Ptn fragment with inosine monophosphate (5 -IMP)... 

In inosine monophosphate dehydrogenase, the monovalent metal ion accelerates the hydride transfer step of the reaction with apparently few other effects on the enzyme structure. Probably the monovalent cation is involved in helping position the nicotinamide cofactor. The active site and location of the potassium ion are shown in Figure 2. Mycophenolic acid in this diagram is an inhibitor that is thought to lock inosine monophosphate into the active site, as shown. Note the large distance between the inhibitor (in the active site) and the K+. 

Inosine monophosphate (IMP) is a key component in the biosynthesis of nucleosides, and it contains 3,7-dihydropurin-6-one (also known as hypoxan-thine) as the base. Draw the structure of this compound. 

Inosine 5 -Monophosphate Dehydrogenase. A series of 21 known inosine 5 -monophosphate dehydrogenase (IMPDH) inhibitors was used to validate a virtual screening protocol. By application of a molecular weight filter (80 < MW < 400), 3425 compounds were extracted from an in-house reagent inventory system. Docking of these compounds into a substrate-IMPDH complex 3D structure was performed with the program FlexX three... 

F. M. McMillan, M. Gaboon, A. White, L. Hedstrom, G.A. Petsko, and D. Ringe. 2000. Crystal structure at 2.4 A resolution of Borrelia burgdorferi inosine 5 -monophosphate dehydrogenase Evidence of a substrate-induced hinged-lid motion by loop 6 Biochemistry 39 4533-4542. (PubMed)... 

Figure i. Molecular structures of inosine (left) and adenosine 5 -monophosphate (right). At acidic pH values, the only Pt binding site expected is N7,... 

Sintchak, M.D. and Nimmesgem, E. (2000) The structure of inosine 5 -monophosphate dehydrogenase and the design of novel inhibitors. Immunopharmacology 47 163-184. 

In 1925, the structure of inosinic acid, which was thought to be the 5 -monophosphate of inosine, was confirmed. Inosinic acid, the first free nucleotide to be recognized, has an interesting history (4). In 1847, the barium salt of this substance was isolated from beef extract by Leibig, who derived the name from the Greek words for muscle fiber. The presence of phosphorus in this substance was not recognized until 1895. In 1909, Levene determined the structure of inosine, a hydrolysis product of inosinic acid, to be the riboside of hypoxanthine with this information, the nucleotide structure of inosinic acid became apparent. 

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