Postdoctoral Research Associate

Kansas Lipidomics Research Center

Division of Biology

Kansas State University

509 Ackert Hall, Manhattan, KS, USA 66506-4901

Office: (785) 532-5756

Lab: (785) 532-5756

Fax: (785) 532-6653

E-mail: giorgis@ksu.edu

         giorgisis@gmail.com

Education:

Ph.D. 2005, Analytical Chemistry, Uppsala University, Uppsala,Sweden.

M.S. 2003, Analytical Chemistry, Uppsala University, Uppsala, Sweden.

B.S. 1997, Chemistry, University of Asmara, Asmara, Eritrea.

Research Interests:

Lipidomics is a rapidly expanding research field in which multiple techniques are utilized to quantitate the hundreds of chemically distinct lipids in cells and determine the molecular mechanism through which they facilitate cellular function. It is also important in the understanding of functional implications and profiling of lipid abnormalities that could be used as a potential biomarker for possible disorder. One feature of complex lipids is that many subtypes of these molecules exist as a diverse mixture in a biological sample. Qualitative and quantitative analysis of these closely related molecules require sensitive and specific analytical methods to detect intact lipid molecules and to differentiate between them. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) is sensitive, accurate and powerful technique for full characterization of cellular lipids. In my research I use direct infusion ESI-MS/MS for characterization and quantification of intact lipid molecular species from complex biological matrix. My main responsibilities and research topic at Kansas Lipidomics Research Center includes:   

• Analytical method development and implementation of new mass spectrometry methods for quantifying intact endogenous lipids and metabolites from different complex biological matrices obtained from various disease and treatments.

• Direct infusion mass spectrometry generates a large amount of data and data handling is the slowest step in lipid analysis. I am involved in the development of functional processing templates for data handling in order to get high sample throughput.
• Development of rapid and efficiency extraction method for high throughput screening of biological samples for alterations in lipid composition.

Publications:

1.       Moreau R.A., Doehlert D.C., Welti R., Isaac G., Roth M., Tamura P. and Nuňez A. “The identification of mono-, di-, tri and tetragalactosyldiacylglycerol and their natural estolides in oat kernels” Submitted, Lipids.

2.       Maeda H., L. Sage T.L., Isaac G., Welti R., and DellaPenna D. “Tocopherols Modulate Extra-Plastidic Polyunsaturated Fatty Acid Metabolism in Arabidopsis at Low Temperature” In Press, Plant Cell.

3.       Botté C., Saïdani N., Mondragon R., Gonzales S., Isaac G., Mui E., McLeod R., Dubremetz J-F., Vial H., Welti R., Cesbron-Delauw M-F., Mercier C. and Maréchal1 E. “Subcellular localization and dynamics of a digalactolipid-like epitope in Toxoplasma gondii” J. Lipid Res. 2008, 49, 746-762.

4.       Welti R., Mui E., Sparks A., Wernimont S., Isaac G., Kirisits M., Roth M.,  Roberts C., Botte C., Marechal E. and McLeod R. “Lipidomic analysis of T. gondii reveals unusual polar lipids”. BioChem. 2007, 46, 13882-13890.

5.       Yang W., Devaiah S.P., Pan X., Isaac G., Welti R., and Wang X. “AtPLAI is an acyl hydrolase involved in basal Jasmonic acid production and Arabidopsis resistance to botrytis cinereai”J. Biol. Chem., 2007, 282, 18116-18128.

6.       Welti R., Isaac G., Tamura P., Esch S.W.1, Sparks A., Jeannotte R., Roth M., Maatta S., Williams T.D., Shah J., and Wang X. “Lipid profiling: Analysis of gene function and physiological responses in Arabidopsis”.ISPL., 2007, 287-291.

7.       Isaac G., Jeannotte R., Esch S.W., Welti R. “New mass spectrometry based strategies for lipids”. Gen. Eng. Rev., 2007, 28, 129-157. ISSN: 0196-3716.

8.       Isaac G., Fredriksson A., Danielsson R., Eriksson P. and Bergquist J. “Brain lipid composition in postnatal iron-induced motor behavior alterations following chronic neuroleptic administration in mice: Characterization using liquid chromatography electrospray ionization”. FEBS Journal, 2006, 273, 2232-2243.

9.       Isaac G., Pernber Z., Gieselmann V., Hansson E., Bergquist J. and Månson J.E. “Sulfatide with short fatty acid dominates in astrocytes and neurons”. FEBS Journal, 2006, 273, 1782-1790.

10.   Isaac G., Waldebäck M., Eriksson U., Odham G. and  Markides K.E. “Total lipid extraction of homogenized and intact lean fish muscle using pressurized fluid extraction and batch extraction techniques”.  J. Agric. Food Chem. 2005, 53, 5506-5512.

11.   Isaac G., Bylund D., Månson J.E., Markides K.E. and Bergquist J. “Analysis of phosphatidylcholine and sphingomyelin molecular species from brain extracts using capillary liquid chromatography electrospray ionization mass spectrometry”. J. Neurosci. Methods, 2003, 128, 111-119.

12.   Pihlström T., Isaac G., Waldebäck M., Osterdahl B.G. and Markides K.E. “Pressurized fluid extraction (PFE) as an alternative general method for determination of pesticide residues in rape seed”. Analyst, 2002, 127, 554-559.