Current Projects (GTL 2 project)
Developing tools for Metabolic flux analysis:
Cellular metabolic flux distribution is defined to be the totality of chemical reactions within a cell. These
reactions are used by living organisms to generate energy and biomass. Traditionally, flux analysis requires
quantitative measurement of many metabolites and solving unknown reactions via linear programming with specific
objective function for solution optimization. A more robust method to assess the complex metabolism is based on
stable isotope labeling of carbon sources: When a carbon substrate (such as glucose) is labeled with a
certain pattern of non-radioactive 13C, the resulting labeling pattern of cellular metabolites permits the
accurate determination of the metabolic fluxes through all related pathways. By knowing the isotopic patterns of
only 10~20 key metabolites, we have good chances to derive the flux distributions in the entire metabolic network
(comprising thousands of enzymatic reactions). Two core techniques are used to achieve this goal: 1) precise
measurements of the labeling pattern of targeted metabolites using nuclear magnetic resonance and mass spectrometers
and 2) interpretation of isotopomer data given by mass spectrometry measurements with a computer model
to calculate the metabolic fluxes catalyzed by thousands of cellular enzymes.
