David H. Croll, Ph.D.
Professor of Chemistry and Physics, Co-Director Interdepartmental Biochemistry Major

Education
B.A., Nasson College
Ph.D., Purdue University
Postdoctoral Fellow, Boston University School of Medicine

Courses Taught

• Biochemistry
• Physical Chemistry: Quantum Mechanics and Spectroscopy
• Scientific Visualization Simulation and Computation
• General Physics
• Biochemistry Seminar
• Survey of Biochemistry
• Tutorials and Independent Studies

I especially enjoy working with students in research and independent study tutorials, where they can explore advanced topics. My research interests are concentrated in the areas of biochemistry, molecular biophysics and mathematical modeling of biological systems. I enjoy exploring the interfaces of traditional disciplines and areas where theory and computation can be closely entwined with experiment and practice. I welcome the opportunity to work closely with students on research projects and tutorials in these areas.

Research Background
My doctoral research was in the area of biological NMR spectroscopy. In my doctoral thesis I characterized the conformations, ionization behavior, and molecular dynamics of avian ovomucoids, members of the Kazal family of serine proteinase inhibitors. During this time I also worked as a spectroscopist at the Purdue University Biochemical Magnetic Resonance Laboratory.

I then spent time as a postdoctoral fellow at the Biophysics Institute of the Boston University School of Medicine, where I did research on the physics and chemistry of lipids and lipoproteins. For this work, I used NMR and a variety of other physical techniques with the goal of understanding the role of physical properties of lipids and lipoproteins in lipid metabolism and atherosclerosis.

Research Interests
Computational approaches for the characterization of biomolecules; protein inhibitors of proteolytic enzymes; molecular evolution
Recent and current projects include the use of information theory to characterize the amino acid sequences and molecular modeling studies of the interaction of the reactive site loops of ovomucoid structural domains in complexes with serine proteinases. We are interested in characterizing the information content, evolution, and structures/biological activity of families of proteins that are inhibitors of proteolytic enzymes.

Lipoprotein and cholesterol metabolism
Projects have focused on responses of lipoproteins and cholesterol metabolism to dietary factors. The comparison of methodologies for determining whole body cholesterol synthesis has been a recent topic of interest.

Mathematical Biology, Complex Systems, and Scientific Visualization and Computation
I am interested in methodologies that can be used to characterize biomolecules and complex systems. Currently, I am developing computational and visualization applications written in Mathematica for my research and teaching activities.

My interests in modeling, computation and visualization contributed to the development of CH 311: Scientific Visualization, Simulation, and Computation, a course that was first offered in fall 2000. Since then I have worked with tutorial and honors students on projects that involve modeling and simulation of biological systems. [LINK]

I have a long-standing interest in instrumentation and Bayesian data analysis techniques and maintain an interest in theoretical and computational aspects of NMR spectroscopy. Recently I have begun exploring some computational aspects of complexity and emergent order in biological systems, ranging from biochemical pathways to populations of organisms. I am also interested in the areas of artificial life and artificial chemistries as an approach to understanding complex biological systems.

Directed Studies: Faculty/Student Research Departmental Honors Thesis Research

• Honors thesis: supervised thesis research of Hilary A. Smith, "Biophysical Modeling: Conformational Analysis of the Cholestrols, Phytosterols and Bile Acids" (1995).
• Honors thesis: supervised thesis research of Kelly M. Thayer, "Protein Inquiry: A Computational Approach" (1999). 
• Honors thesis: supervised thesis research of Suzanne M. Muggeo, "Experimental and Computational Approaches to Biochemical Structure and Reactivity Part II Characterization of Kazal Inhibitors of Serine Proteinases: An Application of Information Theory" (2000). 
• Honors thesis: supervised thesis research of Yussra Al Najaar, "The Game of Life Revisited: A Simple Epidemiological Model" (2005).

Research Articles

1. Ogino, T., Croll, D.H., Kato, I., & Markley, J.L. (1982) Properties of conserved amino acid residues in tandem homologous protein domains. Hydrogen‑1 magnetic resonance studies of the histidines of chicken ovomucoid. Biochemistry 21, 3452-3460.
2. Sallam, M.A.E., Hegazy, E.I.A., Whistler, R.L., Markley, J.L., & Croll, D.H. (1982) Studies on 3-epimeric 2-L-hexulose phenylosazone structure and anomeric configuration of the 3,6-anhydro-osazone derivatives obtained from L-xylo-and-L-lyxo-2-hexulose phenylosazone. Carbohydrate Research 102, 197-206.
3. Croll, D.H., Small, D.M., & Hamilton, J.A. (1985) Molecular motions and thermotropic phase behavior of cholesteryl esters with triolein. Biochemistry 24, 7971-7980.
4. Markley, J.L., Croll, D.H., Krishnamoorthi, R., Ortiz‑Polo, G., Westler, W.M., Bogard, W.C., & Laskowski, M. (1986) One and two‑dimensional NMR spectral analysis of the consequences of single amino acid replacements in proteins. Journal of Cellular Biochemistry 30, 291-309.
5. Croll, D.H., Small, D.M. & Hamilton, J.A. (1986) Temperature dependent molecular motions of saturated acyl cholesteryl esters: A ¹³C NMR study. Journal of Chemical Physics 85, 7380-7387.
6. Croll, D.H., Sripada, P.K., & Hamilton, J.A. (1987) Temperature dependent molecular motions and phase behavior of cholesteryl ester analogues. Journal of Lipid Research 28, 1444-1454.
7. Croll, D.H., Ausman, L.M., & Nicolosi, R.J. (1993) Cholesterol metabolism in New World primates: Comparative studies in two tamarin species (Saguinus oedipus and Saguinus fusicollis), and the squirrel monkey (Saimiri sciureus). Comparative Biochemistry and Physiology Series B 106, 845-853.
8. Jones, P.J.H., Ausman, L.M., Croll, D.H., Feng, J.Y., Schaefer, E.A., & Lichtenstein, A.H. (1998) Validation of deuterium incorporation against sterol balance for measurement of human cholesterol biosynthesis. Journal of Lipid Research 39, 1111-1117.
9. Mitteldorf, J., Ravela, S., Croll, D.H., Bell, R., Seetharam, D., & Boccelli, D. (2002) On the prudent predator: Individual-based modeling of multilevel selection and the evolution of predatory restraint. InterJournal Complex Systems 540. (Electronic journal article submitted S. Chandu Ravela), 20501.
10. Mitteldorf, J., Croll, D.H., & Ravela, S.C. (2003) Multilevel selection and the evolution of predatory restraint. Artificial Life VIII: Procedings of the Eighth International Conference on Artificial Life, 143-152.
11. Croll, D.H., Lichtenstein, A.H., Schaefer E.A., & Ausman, L.M. Saturated and trans- fatty acid containing diets, but not dietary cholesterol, elicit similar fecal sterol excretion and sterol balance in moderate hypercholesterolemics. Manuscript in revision.

Book Chapter

1. Markley, J.L., Croll, D.H., Krishnamoorthi, R.,Ortiz‑Polo, G., Westler, W.M., Bogard, W.C., & Laskowski, M. One and two‑dimensional NMR spectral analysis of the consequences of single amino acid replacements in proteins. In: Protein Structure, Folding, and Design. Proceedings UCLA Symposia, Vol. 39, Dale L. Oxender, ed., Alan R. Liss: New York, 1987.

Published Abstracts

1. Croll, D.H., & Markley, J.L. (1978) Chicken ovomucoid: NMR studies of a glycoprotein, Proceedings 6th International Biophysics Congress, Kyoto, Japan, Abs.IV‑10 (553), p.183.
2. Croll, D.H., & Markley, J.L. (1980) Characterization of chicken and Japanese quail ovomucoids and their carboxyl terminal structural domains by NMR spectroscopy, 9th International Conference on Magnetic Resonance in Biological Systems (COMABIO 9), Abs.
3. Sallam, M.A.E., Hegazy, E.I.A., Whistler, R.L., Markley, J.L., & Croll, D.H. (1981) Structure and anomeric configuration of the 3,6,-anhydro-osazone derivatives obtained from L-xylo-hexulose phenylosazone and L-lyxo-hexulose phenylosazone. 182 ACS National Meeting American Chemical Society Division of Carbohydrates Abs. 47.
4. Croll, D.H., Small, D.M., & Hamilton, J.A. (1985) ¹³C NMR studies of cholesteryl esters and their analogues: steroid ring dynamics near the onset of thermotropic mesophase formation. Biophysical Journal 47A.
5. Walsh, M.T. Croll, D.H., Sparrow, J.T., Sparrow, D.A., Small, D.M. & Hamilton, J.A. (1988) Structural investigation of the solution conformation of a model peptide - the receptor binding region of apolipoprotein E. Arteriosclerosis 8(5), 605A.
6. Ausman, L.M., Croll, D.H., Wood, M., Nair, P.P., Schaefer, E.J., & Lichtenstein, A.H. (1996) Hydrogenation of corn oil decreases total fecal steroid excretion. The FASEB Journal 10(3): A508.
7. Ausman, L.M., Croll, D.H., Jones, P.J.H., Schaefer, E., & Lichtenstein, A.H. (1997) Impact of dietary fat type on low density lipoprotein cholesterol levels partially mediated by total body sterol balance. The FASEB Journal 11(3): A355.
8. Croll, D.H., Ausman, L.M., Schaefer, E.J., & Lichtenstein, A.H. (1998) De novo cholesterol synthesis unchanged in corn oil or tallow diets supplemented with cholesterol. The FASEB Journal 12(5 Part II): A817.
9. Croll, D.H., Ausman, L.M., Schaefer, E.J., & Lichtenstein, A.H. (2000) Saturated and trans-containing diets elicit similar fecal sterol excretion and balance in mild hypercholesterolemics. The FASEB Journal 14(4): A48.
10. Mitteldorf, J., Ravela C., Bell, R., Boccelli, D.L., Croll, D.H., & Seetharam, D. (2002) On the prudent predator. 4^th International Conference on Complex Systems [Th-Ev-Evol], p. 84.
11. Mitteldorf, J., Croll, D.H., & Ravela, S.C. (2002) Multilevel selection and the evolution of predatory restraint. Artificial Life VIII The 8th International Conference on the Simulation and Synthesis of Living Systems Abs.