Enzymes mechanistic studies, hydrogen isotope

Exact localization of the hydrogen isotope is usually required, and it is inadvisable to rely on the method of synthesis, as the label is not always situated entirely at the position predicted.69 In many mechanistic and biological studies with enzymes, the position of the label alters during the reaction, and, in others, where a proton isotope from the solvent is incorporated, it is important to localize the incorporated isotope, and, if it is at a methylene group, to determine its stereochemistry. 

Most of the sugars specifically labeled with isotopes of hydrogen that have been synthesized were prepared for use in mechanistic studies of enzymes. 

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