Glucose radiolabeled

Cell lysates from mutant strains of X. campestris were incubated with radiolabelled UDP[14C] glucose or GDP[,4C] mannose, the other sugar nudeotide substrates being unlabelled. The reaction mixture was then divided into lipid and soluble fractions. Where would you expect the radiolabel to be found and what produd, if any, would you expert from strains with defidendes in the following genes ... 

A yeast culture is fermenting glucose to ethanol. To ensure that the C02 released during fermentation is radiolabeled, what carbon(s) of glucose must be labeled with l4C ... 

Since the glucose-lysine reaction mixture used in this study consisted of a number of different substances, it was of interest to study whether the observed inhibitory effect in vitro could be attributed to some specific compound(s). In order to obtain a separation, an aliquot of the LMW fraction, radiolabel led by [U- glucose added to the reactants, was applied on a Sephadex G-50 column and eluted with water. The UV absorbance was recorded and the eluate was collected in fractions. The degree of inhibition effected by small samples of equal volume from each fraction and exerted on carboxypeptidase A and purified aminopeptidase N was determined as well as the radioactivity... 

Finally, caution should be exerted when determining kinetic data with radiolabelled sugars. Trueb, et al. (32) found that labelled glucose from several manufacturers contained radioactive impurities of unknown structure which often reacted faster than glucose itself. Purification methods can be found in reference 31. 

Several academic partners and Siemens Medical Solutions USA Inc. (Molecular Imaging) in Culver City, USA, made the synthesis of an [18F]fluoride-radiolabeled molecular imaging probe, 2-deoxy-2-[18F]fluoro-D-glucose in an integrated microfluidic device (see Figure 5.1) [21]. Five sequential processes were made, and they are [18F]fluoride concentration, water evaporation, radiofluorination, solvent exchange and hydrolytic deprotection. The half-life of [lsF]fluorine (t1/2 = llOmin) makes rapid synthesis of doses essential. This is one of the first examples of an automated multistep synthesis in microflow fashion. 

The first argument was supplied by Post and Vincent (4o) in their study of the incorporation of radiolabeled glucose in tissue fractions of normal... 

Answer We can represent ATP as A-P-P-P (the P farthest from A is the 7 P) and a radiolabeled phosphate group as P. One possible reaction for 7-labeled ATP would be phosphorylation of glucose ... 

The biosyntheses of STA and REB were studied by feeding radiolabeled precursors to Lentzea albida (formerly Streptomyces staurosporeus) [9-13] and Lechevalieria aero-colonigmes (formerly Saccharothix aerocolonigenes) [14,15], respectively. The results established that the indolocarbazole core was derived from two units of tryptophan (with the carbon skeleton incorporated intact), while the sugar moiety was derived from glucose and methionine (for methylations). 

Radiolabeled UDP-glucose and sucrose-P were separated on a Selectispher-10 boronate column (5 mm x 250 mm). The mobile phase was 0.12 M sodium phosphate (pH 7.6) delivered at a rate of 1 mL/min. The column eluent was monitored for absorbance at 262 nm, and for radioactivity by a radioactive flow-through detector. 

Nothing is known of the biosynthesis of tetrodotoxin, although the involvement of arginine and an isoprenoid has been postulated (191). Radiolabeled acetate, arginine, citrulline, or glucose were not incorporated into the tetrodotoxin of newts of the genus Taricha (210). 

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