Christa L. Colyer

Christa_Colyer2013Professor

B.Sc. (Honours) 1988, Trent University (Peterborough, Canada)
M.Sc. (Distinction) 1991, University of Guelph (Guelph, Canada)
Ph.D. 1995, Queen’s University (Kingston, Canada)
NSERC Postdoctoral Fellow 1995-97, University of Alberta (Edmonton, Canada)
Assistant Professor 1997-2003, Wake Forest University
Dunn-Riley Faculty Fellow 2002-03, Wake Forest University
Associate Professor 2003-04, University of Ontario Institute of Technology (Oshawa, Canada)
Associate Professor 2004-2010, Wake Forest University
Department Chair 2006 – 2014, Wake Forest University
Professor 2010 – present, Wake Forest University

 

Office: Salem 116B
Phone: (336) 758-4936
Email: colyercl@wfu.edu

Colyer Research Group

Colyer Research Group

High Efficiency Separations of Biologically-Important Molecules by Capillary Electrophoresis

Proteins  and other large biopolymers have tremendous clinical, biological and even  environmental significance, yet it can be a difficult task to separate them in  complex mixtures and to measure trace quantities present in such mixtures. Dr.  Colyer’s research program addresses these difficulties by developing new  bioanalytical separation methods, with a particular emphasis on the utility of  capillary electrophoresis with laser-induced fluorescence detection. The  determination of phycobiliproteins and investigations into the mechanism of  noncovalent binding of nonfluorescent proteins with visible and near-infrared  organic dyes are examples of current projects in the Colyer lab.

Phycobiliprotein  analysis:
Phycobiliproteins are water soluble, highly fluorescent proteins produced in  nature by cyanobacteria (blue-green algae) and red algae. These proteins can  absorb light energy across a region that is not efficiently absorbed by  chlorophyll a, and so they serve to enhance the light-harvesting capabilities  of their host seawater organisms. To facilitate phycobiliprotein  determinations, we are developing high-speed and high-efficiency extraction  methods, followed by high-sensitivity CE-LIF separation methods for not only  the proteins themselves, but also for their “bilin” pigments and the  intact microorganisms that create these proteins. Our studies will ultimately  provide a routine analytical tool for quantifying the diagnostic  phycobiliproteins in seawater, allowing for better measurements of cyanobacterial  biomass and distributions, thus improving estimates of ocean primary  production, and the role that oceans play in the global carbon cycle.

Noncovalent,  near-infrared labels as facilitators of protein determination:
By coming to understand the nature of noncovalent interactions between various  dye and protein molecules, it will be possible to develop efficient, high  sensitivity analytical methods with applicability to the separation and  quantitation of nonfluorescent proteins in complex mixtures. Noncovalent  labeling strategies, coupled with CE and laser-induced fluorescence (LIF), are  designed to overcome the disadvantages normally associated with protein  derivatization, such as increased sample preparation and handling, restrictive  solution pH and temperature conditions, and decreased separation efficiency due  to the formation and partial resolution of multiple, differently-labeled  species. To this end, appropriate buffer conditions are found to render visible  and near-infrared dyes (especially squarylium dyes and boronic-acid based  probes) non-fluorescent until noncovalently bound to a mixture of proteins, at  which point a significant enhancement in the fluorescence of the bound dye will  allow for detection of the proteins by CE-LIF. Our applied CE studies are  accompanied by the investigation of some underlying physical phenomena that  affect separation and on-column reaction performance. For example, the reaction  kinetics of protein-dye interactions, the stability of protein-dye complexes,  their stoichiometries and affinities, and their mobilities relative to those of  unlabelled proteins, are important to the field of CE and to many other  disciplines, too. As such, we design experiments to measure these parameters so  that their impact can be quantitatively assessed.

Graduate and undergraduate students in our research group are exposed to many aspects of chemical research. Projects in our group allow students to develop a wide variety of skills beyond separation method development. These skills include basic biochemical sample handling, derivatization chemistry, biomolecule conjugation, laser optics, spectrophotometric methods, electronics, data acquisition, software programming, and statistical analysis. Students are encouraged to present their research work at regional, national, and international conferences, and are given opportunities to collaborate with researchers at other institutions.

Recent Publications

S. Saito, T. Maeda, H. Nakazumi, and C.L. Colyer, Electrophoretic behavior of gram-positive bacteria using polymer-enhanced capillary transient isotachophoresis with emissive boronic acid functionalized squarylium dye. Analytical Sciences. 29: 157-159 (2013).

C.L. Colyer, ConfChem Conference on Case-Based Studies in Chemical Education: You (Want To) Call Yourself a Case Study Teacher? Journal of Chemical Education. DOI: 10.1021/ed200789k (December 12, 2012).

X. Lin, S. Rockett, T.L. Massie, G.B. Turner, T. Maeda, H. Nakazumi, and C.L. Colyer, Asymmetric mon- and bis-squarylium dyes as pre-column and on-column labels for protein analysis by capillary electrophoresis with laser-induced fluorescence detection. Journal of Analytical & Bioanalytical Techniques. DOI:10.4172/2155-9872.S9-001 (2012).

S. Saito, T.L. Massie, T. Maeda, H. Nakazumi, and C.L. Colyer , A Long-Wavelength Fluorescent Squarylium Cyanine Dye Possessing Boronic Acid for Sensing Monosaccharides and Glycoproteins with High Enhancement in Aqueous Solution. Sensors. 12: 5420-5431 (2012).

A. R. Gerardi, X. Lin, Z. S. Breitbach, D. W. Armstrong, and C. L. Colyer, CE-ESI-MS Analysis of divalent organic and inorganic anions using a tricationic complexing reagent. Electrophoresis. 33: 734-740 (2012).

S. Saito, T.L. Massie, T. Maeda, H. Nakazumi, and C.L. Colyer, On-column labeling of gram-positive bacteria with a novel boronic acid functionalized squarylium cyanine dye for analysis by polymer-enhanced capillary transient isotachophoresis.  Analytical Chemistry. 84: 2452-2458 (2012).

C.L. Colyer, Childbed Fever: A 19th-Century Mystery. In: Science Stories: Using Case Studies to Teach Critical Thinking. C.F. Herreid, N.A. Schiller, and K.F. Herreid, Eds. NSTA Press, Arlington, VA (2012) Ch. 5.

S. Selem Abd El-Hay, C.L. Colyer, W.S. Hassan, and A. Shalaby,  Spectrofluorimetric determination of Etodolac, Moxepril HCl and Fexofenadine HCl using europium sensitized fluorescence in bulk and pharmaceutical preparations. Journal of Fluorescence. 22:247-252 (2012).