Non-statistical label distribution in biosynthetic 13C enriched amino acids

A combined 13C nuclear magnetic resonance and field desorption mass spectrometric investigation of algae grown on 13CO2 has shown that the isotopic enrichment of amino acids extracted therefrom is neither uniform nor statistical. The use of these two independent technqiues allows a new, detailed and accurate insight into the label distribution resulting from biosynthesis. The observed deviations from the statistical abundances are systematic. A system for classifying each member of the complex ensemble of isotopic species has been devised, so that the isotopomers may be ordered according to their relative probability of occurrence. (orig.)