Mass isotopomer pattern and precursor-product relationship.
Biol Mass Spectrom
; 21(2): 114-22, 1992 Feb.
Article
em En
| MEDLINE
| ID: mdl-1606182
ABSTRACT
The synthesis of a homonucleus polymer from its labeled precursor will lead to the formation of molecules with different masses. The distribution of these mass isotopomers is strictly a function of the enrichment of the 13C-labeled precursor, and can thus be used for the determination of the precursor enrichment and product dilution in the de novo synthesis of the polymer. We present here a study of the isotopomer pattern of a polymer of acetate in the form of glucose pentaacetate synthesized from 13C-enriched acetic anhydride. The molecular ion contains four acetyl units. Its synthesis is analogous to that of octanoic acid from acetyl coenzyme A. The process of obtaining the mass isotopomer distribution in the tetraacetyl moiety from the ion cluster of m/z 331 of glucose pentaacetate is illustrated. After correcting for the contribution of 13C natural abundance, the plot of the ratio of mass isotopomers (m4/m2) against the observed enrichment of the tetraacetate moiety yielded a straight line with a slope of 1.45. The ratio was not altered by dilution with pre-existing unenriched product, as predicted. The slope of the observed linear relationship agreed with the general formula (N-(j-1))/j for the ratio of any two consecutive mass isotopomers (mj/mj-1). Theoretical and practical aspects of determining precursor enrichment from isotopomer pattern in polymers are discussed.
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Base de dados:
MEDLINE
Assunto principal:
Polímeros
Idioma:
En
Revista:
Biol Mass Spectrom
Assunto da revista:
BIOQUIMICA
Ano de publicação:
1992
Tipo de documento:
Article