Uridine 5’-diphosphate UDP

Figure 8.19. Sequence reactions from aspartic acid (AA) and carbamoyl phosphate (CP) to the end product, cytidine triphosphate (CTP). The first reaction is catalyzed by ATCase. The intermediary compounds are N-carbamoyl aspartic acid (N-CAA), L-dihydroorotic acid (L-DHOA), orotic acid (OA), orotidine 5 -phosphate (0-5 -P), uridine 5 -phosphate (U-5 -P), uridine diphosphate (UDP), and uridine triphosphate (UTP).

Uracil Uridine Uridylic acid Uridine monophosphate (UMP) Uridine diphosphate (UDP) Uridine triphosphate (UTP)... 

There is a growing number of published examples of the utility of screening patients for pharmacogenetic markers prior to chemotherapy selection (1). Many published markers of association with chemotherapy outcome or toxicity still require validation in prospective studies. Examples of well-characterized pharmacogenetic markers include thiopurine methyltransferase (TPMT), UGT (uridine diphosphate [UDP]-glucuronosyltransferase) lAl, and epidermal growth factor receptor (EGER). 

Glucose 1-phosphate then is coupled with uridine diphosphate (UDP) to form UDP-glucose, the main donor of glucosyl residues during the construction of glycogen. 

Figure 9-8. Pathway for metabolism of heme and excretion as bilirubin. Heme degradation begins with heme oxygenase, which catalyzes a complex set of reactions that simultaneously open the protoporphyrin ring structure and release iron in the ferric (Fe ) state. This is the only physiologic reaction that makes endogenous CO in the body a portion of the small amounts made is expired via the lungs. The structure of the main form of bilirubin is shown. Symbols for the side groups indicate M, methyl V, vinyl P, propyl. Formation of the diglucuronide is catalyzed by bilirubin uridine diphosphate (UDP) glucuronyltransferase. RE, reticuloendothelial.

The enzyme is also responsible for converting cytidine diphosphate (CDP) to 2 -dCDP and uridine diphosphate (UDP) to 2 -dUDP for use in making nucleotides for DNA synthesis. 

From extensive analysis of recombinant proteins, and the crystal structure of A. thaliana protein, detailed reaction mechanisms have been proposed. The ANS reaction likely proceeds via stereospecific hydroxylation of the leucoanthocyanidin (flavan-3,4-cA-diol) at the C-3 to give a flavan-3,3,4-triol, which spontaneously 2,3-dehydrates and isomerizes to 2-flaven-3,4-diol, which then spontaneously isomerizes to a thermodynamically more stable anthocyanidin pseudobase, 3-flaven-2,3-diol (Figure 3.2). The formation of 3-flaven-2,3-diol via the 2-flaven-3,4-diol was previously hypothesized by Heller and Forkmann. The reaction sequence, and the subsequent formation of the anthocyanidin 3-D-glycoside, does not require activity of a separate dehydratase, which was once postulated. Recombinant ANS and uridine diphosphate (UDP)-glucose flavonoid 3-D-glucosyltransferase (F3GT, sometimes... 

This is the most common single metabolic reaction undergone by drugs, which occurs in the liver. These reactions are catalyzed by a family of enzymes known as uridine diphosphate (UDP) glucuronyl transferases. These enzymes are present in liver, kidney, intestine and lungs. 

The galactose 1-phosphate is then converted to its epimer at C-4, glucose 1-phosphate, by a set of reactions in which uridine diphosphate (UDP) functions as a coenzyme-like carrier of hexose groups (Fig. 14-11). The epimerization involves first the oxidation of the C-4 —OH group to a ketone, then reduction of the ketone to an —OH, with inversion of the configuration at C-4. NAD is the cofactor for both the oxidation and the reduction. 

Glycoproteins are synthesized by passing through two organelles, the ER and the Golgi apparatus [4], The biosynthesis of N-linked oligosaccharides initiates with the cytosolic transfer of GlcNAc from its uridine diphosphate (UDP) form onto dolichol... 

UDP uridine diphosphate UDP-galactose uridine diphosphate galactose UDP-glucose uridine diphosphate glucose UMP uridine monophosphate UTP uridine triphosphate Val valine... 

Polycyclic aromatic amines are readily absorbed into the body via the gastrointestinal tract, where metabolic activation takes place. Aryl amines are N-hydroxylated and subsequently glucuronidated via uridine diphosphate (UDP)-glucuronosyl transferase or sulfated by sulfotransferases, N-acetylation of the amine, and 0-acetylation of the N-hydroxy amine can occur. 

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