Monitoring metabolism changes in Escherichia coli during amino acid starvation using CE-MS

CHED 253

G. Aaron Hightower, jesusdrumma@aol.com, Department of Chemistry, Southeastern Oklahoma State University, 1405 N. 4th, c/o Dr. Tim Smith - PO Box 4025, Durant, OK 74701, Matt Traxler, mtraxler@ou.edu, Department of Microbiology, University of Oklahoma, Norman, OK 74701, Tyrrell Conway, tconway@ou.edu, Botany and Microbiology, University of Oklahoma, Norman, OK 73019, and Joel T. Smith, tsmith@sosu.edu, Department of Chemistry, Computer and Physical Sciences, Southeastern Oklahoma State University, 1405 N. 4th Ave., Durant, OK 74701.
The impact of amino acid (isoleucine) starvation on amino acid metabolism in E. coli was explored for wild type MG 1655 and a mutant (relA spoT double mutant). A unique analytical method was developed to determine the amino acid concentrations in a growth media. The method utilized capillary electrophoresis-electrospray ionization-mass spectrometer (CE-MS). The amino acids were separated using a 1 M formic acid electrolyte (pH 1.8) where the amino acids migrated as cations toward the mass spectrometer. Once the E. coli consumed all of the isoleucine, the E. coli must reprogram its metabolism to continue to grow. Significant differences were observed between the mutant and WT. The analytical reproducibility was less than 3% CV. The generation of the chemical data set was complimented with a microarray data set that showed gene regulation. The combination of microarray and chemical data allowed for reprogrammed metabolism pathways to be proposed.
 

Undergraduate Research Poster Session: Analytical Chemistry
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008