Mark Duncan, Ph.D.
Professor of Medicine
Department of Pediatrics/Div Endocrinology
University of Colorado Denver
at Fitzsimons (RC1 South Tower, Room 12-104)
P.O. Box 6611 MS 8119
Aurora, Colorado 80045
Research Interests
We are developing new technologies for more sensitive and efficient analysis. Currently, the usual approach to protein separation is 2D gel electrophoresis. Although powerful, this step is labor-intensive and time-consuming.We are currently developing qualitative and quantitative protein analyses in biological tissues and fluids that avoid this step.
Our attention is being directed in three areas:
(1) More rapid and reliable high-throughput protein identification;
(2) Practical and precise absolute quantification of proteins in complex biological samples; and
(3) The identification and assessment of the extent of protein posttranslational modification.
While methods for detailed and rapid protein identification are now established, practical approaches to sensitive protein quantification are not available. This means that proteins can be identified, but information on the levels of these is much more difficult to obtain, and when available, this information is imprecise and relative.
We are exploring approaches to absolute protein quantification that provide precise, absolute and wide-ranging quantification without the need for chemical modification. Such methods will unquestionably improve our understanding of molecular pathways in health and disease. Our view is that these methods, once developed, will also yield improved diagnostic markers of disease, improved prognostic indices and ultimately, better approaches to the treatment of disease. In addition, we are interested in "unplanned" protein modification: oxidation, nitration, chlorination and other potentially deleterious events. We have developed, and continue to refine, exquisitely sensitive and precise approaches to quantifying and localizing this damage.
Collaborative Research Ventures - Investigators in the mass spectrometry facility work with groups on this campus, at other institutions in the USA and overseas. Some of the key areas of activity include, for example: studies of (differential) protein expression in lung cancer; oxidative damage in cystic fibrosis; oxidative damage in neurodegenerative disease; oxidative damage in rheumatoid arthritis; and changes in protein expression in heart disease. We have already undertaken an extensive analysis of protein expression in normal and diseased lung tissue, and we are now developing approaches to protein quantification in these same tissues. Work of this nature requires a commitment to innovation, hand-in-hand with the application of cutting-edge methods to goal-orientated biomedical research.
Recent Publications
Blount BC, Duncan MW. 1997. Trace quantification of the oxidative damage products, meta- and ortho-tyrosine, in biological samples by gas chromatography- electron capture negative ionization mass spectrometry. Anal Biochem 244(2):270-6
Cerpa-Poljak, A., Lahnstein, J., Mason, K.E., Smythe, G.A. and Duncan, M.W. 1997. Mass spectrometric identification and quantification of hemorphins extracted from human adrenal and pheochromocytoma tissue. J Neurochem 68(4):1712-9
Christen, S., Woodall, A.A., Shigenaga, M.K., Southwell- Keely, P.T., Duncan, M.W. and Ames, B.N. 1997 Gamma-tocopherol traps mutagenic electrophiles Proc Natl Acad Sci U S A. 94(7):3217-22
Cordwell, S.J., Wasinger, V.C., Cerpa-Poljak, A., Duncan, M.W. and Humphery-Smith, I. 1997. Conserved motifs as the basis for recognition of homologous proteins across species boundaries using peptide-mass fingerprinting. J Mass Spectrom. 32(4):370-8
Smythe, G.A., Matanovic, G., Donghui, Y. and Duncan, M.W. 1999. Trifluoroacetic Anhydride-Catalyzed Nitration of Toluene as an Approach to the Specific Analysis of Nitrate by Gas Chromatography - Mass Spectrometry: Nitric Oxide. Biol Chem. 3:67-74
Charlton, T.S., Ingelse, B.A., Black, D.S., Craig, D.C., Mason, K.E., and Duncan, M.W. 1999. A covalent thymine-tyrosine adduct involved in DNA-protein crosslinks: synthesis, characterization, and quantification. Free Radic Biol Med 1999 Aug;27(3-4):254-61
Yi, D., Ingelse, B.A., Duncan, M.W. and Smythe, G.A. 2000. Quantification of 3-Nitrotyrosine in Biological Tissues and Fluids: Generating Valid Results by Eliminating Artefactual Formation. J. Am. Soc. Mass Spectrom. 11:578-586
Fessler MB, Malcolm KC, Duncan MW, Worthen GS. Lipopolysaccharide stimulation of the human neutrophil: an analysis of changes in gene transcription and protein expression by oligonucleotide microarrays and proteomics. Chest. 2002 Mar;121(3 Suppl):75S-76S
Naranda T, Kaufman RI, Li J, Wong K, Boge A, Hallen D, Fung KY, Duncan
MW, Andersen N, Goldstein A, Olsson L. Activation of erythropoietin receptor
through a novel extracellular binding site.
Endocrinology 2002 Jun;143(6):2293-302
Fessler MB, Malcolm KC, Duncan MW, Worthen GS. A genomic and proteomic analysis of activation of the human neutrophil by lipopolysaccharide and its mediation by p38 mitogen-activated protein kinase. J Biol Chem. 2002 Aug 30;277(35):31291-302
Bucknall M, Fung KY, Duncan MW. Practical quantitative biomedical applications
of MALDI-TOF mass spectrometry. J Am Soc Mass Spectrom 2002 Sep;13(9):1015-27
