Sugar phosphates trehalose-6-phosphate

Hence, noncrystallizing sugars (sucrose, trehalose) or polyols (dextran, polyethylene glycol) are added to the formulation to minimize cold denaturation during freeze-thaw or during lyophiliza-tion. Also, nonionic surfactants like polysorbates or Pluronics are included to prevent mAb adsorption at the interface of ice, air, or other product contact surfaces. Use of ionic surfactants like SDS is not advisable due to their potential to cause tissue irritation and hemolysis. Preformulation studies are important to identify the pH of maximum stability. For most mAbs, it is in the range of pH 5.0 to 6.5. Common buffers used to control the pH of the solution include phosphate, citrate, histidine, and glycine. 

It has been discovered that rare-earth catalysts are highly specific for the dephosphorylation of sugar phosphates with a phosphatase. At 37°, for instance, a, a-trehalose 6-phosphate is completely unhydrolyzed by phosphatase in the absence of rare-earth catalysts, even after 144 hours. However, in the presence of cerium nitrate, over 20% hydrolysis occurs in this period of time. 

Some salts of sugar phosphates may be obtained in cr) talline form, as in the case of barium glucose 6-phosphate and barium trehalose phosphate. Salts of organic bases usually tend to crystallize more easily. Those which have been found more useful are cyclohexylamine, brucine, strychnine and benzylamine. 

Pukl and Prosek (1990) used TLC-densitometry to quantify glucose, fructose, and saccharose single or multiple developments were used with a solvent system consisting of acetonitrile-methanol-pH 5.5 phosphate buffer (85 5 15) sugars were detected with a diphenylamine-aniline reagent and scanning was at 440 and 515 nm. Fell (1990) used TLC-densitometry to quantify trehalose, glucose, and fructose at 125-2000 ng-levels in less than 1 pi samples of insect hemolymph. 

Lunn, J.E., Fed, R., Hendriks, J.H.M., Gibon, Y, Morcuende, R., Osuna, D., Scheible, W.R., Carillo, P., Hajirezaei, M.R., and Stitt, M. (2006). Sugar-induced increases in trehalose 6-phosphate are correlated with redox activation of ADPgIucose pyrophosphorylase and higher rates of starch synthesis in Arabidopsis thaliana. Biochem. J. 397,139-148. 

Insect muscle utilizes the Meyerhof sequence only as far as pyruvate, and the NADH produced during triosephosphate oxidation seems to be reoxidized by the reduction of dihydroxyacetone phosphate to glycerophosphate (Chance and Sacktor, 1958). The major sugar in the plasma is a,a-trehalose, a disaccharide of glucose, and it plays a major part in the glucose transport system of insects (Wyatt and Kalf, 1957). For a review of insect biochemistry, see Goodwin (1965). 

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