Biosynthetic control of the natural abundance of carbon 13 at specific positions within fatty acids in Escherichia coli. Evidence regarding the coupling of fatty acid and phospholipid synthesis

Journal Article · Wed Dec 10 04:00:00 EST 1980 · J. Biol. Chem.; (United States)

OSTI ID:6677989

Monson, K D; Hayes, J M

Stable carbon isotope ratios (/sup 13/C//sup 12/C) at natural abundance levels have been determined for individual carbon atoms in each of the major phospholipid fatty acids of Escherichia coli grown on glucose as the sole carbon source. Two models were constructed for the isotope effects and carbon flow pathways which must be responsible for the observed isotopic fractionations. Both models incorporate a branch in the carbon flow at which fatty acyl-acyl carrier protein (acyl-ACP) is utilized either for complex lipid synthesis or for elongation by fatty acid synthetase. Depletion of carbon 13 in the carboxyl groups of myristic and palmitoleic acids (relative to carbonyl groups in precursor acyl-ACP's) was observed to occur at this branching site. Only one of the models was consistent both with this observation and with the observation that exogenous fatty acids are incorporated into phospholipids but are not elongated. The successful model has free fatty acid as the intermediate product coupling fatty acid biosynthesis to phospholipid synthesis. Essential to this pathway are those reactions catalyzed by thioesterases I and II as well as acyl-ACP synthetase, enzymes whose roles have previously been unknown in vivo.

• Research Organization: Indiana Univ., Bloomington
• OSTI ID: 6677989
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 255:23; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
BACTERIA
BIOLOGICAL MODELS
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
CARBOHYDRATES
CARBON 12
CARBON 13
CARBON ISOTOPES
CARBOXYLIC ACIDS
CHEMICAL COMPOSITION
CULTURE MEDIA
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GLUCOSE
HEXOSES
IN VIVO
ISOTOPE RATIO
ISOTOPES
LIGASES
LIGHT NUCLEI
METABOLISM
MICROORGANISMS
MONOSACCHARIDES
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PRECURSOR
SACCHARIDES
STABLE ISOTOPES
SYNTHESIS