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William E.
Kurtin
Professor Biochemistry phone: (210) 999-7382 FAX: (210) 999-7569 email: wkurtin@trinity.edu |
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William E.
Kurtin
Professor Biochemistry phone: (210) 999-7382 FAX: (210) 999-7569 email: wkurtin@trinity.edu |
Courses Taught:
Biochemistry and Laboratory
Molecular Spectroscopy
Advanced Biochemistry
Instrumental Analysis
Physical Biochemistry
Polymer Chemistry
Analytical Chemistry
Origin of Life
General Chemistry and Laboratory
Technical Writing (Cont. Ed.)
Organic Chemistry and Laboratory
Current research efforts are directed toward understanding the interaction of the bile pigment bilirubin (BR) with the lipid components of hepatic bile, especially the bile salts (BS). Knowledge of these molecular interactions is essential in order to understand the physical chemistry involved in gallstone formation.
When BR complexes with BS molecules, the pigment absorption and fluorescence properties change significantly. We are attempting to use these observations to obtain information about the specific conformations and aggregation behavior of these molecules in solutions which resemble natural bile. We also plan to use computer modeling studies and molecular dynamics calculations to make predictions about the molecular interactions. Other work will be devoted to the development of bioanalytical methods for determining the relative binding affinity of different bile salts for BR.
Acid Dissociation Constants of Bilirubin and Related Carboxylic Acid
Compounds in Bile Salt Solutions
William E. Kurtin†, Jason Enz†, Celeste Dunsmoor†, Neil Evans†, David
A. Lightner*
†Department of Chemistry, Trinity University, and the *Department of
Chemistry and Biochemistry, University of Nevada, Reno
Arch. Biochem. Biophys., 381(1), 83-91, 2000.
Abstract
Bilirubin, the yellow-orange tetrapyrrole pigment
of jaundice, is essentially insoluble in pure water, but is much more soluble
in solutions of bile salts such as sodium taurocholate. The biophysical
chemistry of bilirubin in bile salt solutions is affected by changes in
the pH of the solution in the range 5-9, suggesting that interactions with
bile salt molecules and micelles may alter the acidity of the pigment.
We have examined this possibility by determining the apparent pKa values
for a series of carboxyl 13C-enriched model compounds, including
the bilirubin analogs mesobilirubin XIIIa (MBR)
and xanthobilirubic acid (XBR), in solutions of sodium taurocholate
(TC) and sodium taurodeoxycholate (TDC). Apparent pKa values were determined
by 13C NMR titrations in dimethyl sulfoxide-water mixtures.
The results show that the acidity of all compounds is decreased, or pKa
increased, in micellar bile salt solution relative to pure water, and that
the effect is greatest for the larger, less water-soluble compounds. We
have proposed a model to explain these results, and discussed the implications
of these findings for the biophysical chemistry of bilirubin in bile.
Apparent pKa Values in DMSO-H2O
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KURTIN, William E., Ph.D.
Professor
30219 Twin Ridge Dr.
Department of Chemistry
Bulverde, TX 78163
Trinity University
Home Phone: (830) 980-2927
715 Stadium Drive
San Antonio, TX 78212
Date of Birth: February 2, 1943
Place of Birth: Houston, TX
Marital Status: Married, four children, five grandchildren
Eduication:
B.A. Chemistry, University of St. Thomas, Houston, Texas, 1965
Ph.D. Biochemistry, Texas Tech University, Lubbock, Texas, 1969 (Advisor:
P.-S. Song)
Honors:
Graduate School Summer Research Grantee, Texas Tech University, 1968,
1969.
Robert A. Welch Predoctoral Fellowship, Texas Tech University, 1966-1969.
NIH Postdoctoral Fellowship, Baylor College of Medicine, 1969-1970.
Fulbright Scholar, Johannes Kepler University, Austria, 1989-90 (Collaborator:
H. Falk)
Consultant, Project Kaleidoscope, 1994-1997
Professional Experience:
1969-70 NIH Postdoctoral Fellow Baylor College of Medicine
1970-77 Assistant Professor (Chemistry) Trinity University
1977-83 Associate Professor (Chemistry) Trinity University
1980-81 Acting Chairman, Chemistry Trinity University
1981-88 Chairman, Chemistry Trinity University
1983- Professor (Chemistry) Trinity University
1984 (Fall) Visiting Research Professor U.T. Health
Science Center,
1985, 1987, 1989 (Summer) San Antonio
1990 (Spring) Fulbright Scholar Johannes Kepler U.,
Linz, Austria
1991-92 Co-Chair, Chemistry Trinity University
1992-98 Chairman, Chemistry Trinity University
1998 (Fall) Adjunct Research Professor Univ. of Nevada,
Reno
Professional Societies and Organizations:
American Chemical Society
American Society for Biochemistry and Molecular Biology
Fulbright Association
Sigma Xi
Union of Concerned Scientists
Council for Undergraduate Research
Current Grants:
Research Experiences for Undergraduates Site at Trinity University,
National Science Foundation,
1999-2001, $165,000.
Publications:
29 publications prior to 1995
A. K. Diehl, W. H. Schwesinger, D. R. Holleman, Jr., J. B. Chapman, and W. E. Kurtin, "Clinical Correlates of Gallstone Composition", Am. J. Gastroenterology, 90, 967-72 (1995).
W. E. Kurtin, "Partners with San Antonio Colleges : A Successful REU Experiment", CUR Quarterly, September, 1996.
A. K. Diehl, W. H. Schwesinger, W. E. Kurtin, D. R. Holleman, and J. B. Chapman, "Characteristics of Patients with Single versus Multiple Cholesterol Gallstones", Dig. Dis. Sci., 42, 953-54 (1997).
M. P. Nittler, R. A. Desai, D. A. Salikof, W. E. Kurtin, and M. M. Bushey, "Bile Salt Micellar Electrokinetic Chromatography of Bilirubin and Related Compounds", J. Chromatography A, 779, 205-214, (1997).
W. E. Kurtin, R. Heo, D. J. Breimeir, N. T.-V. Tran, E. Elizondo, R. E. Salas, M. Morales, L. Huang, and B. Frank, "Effects of pH on the Absorption, Emission, and Light Scattering Spectroscopy of Bilirubin and Xanthobilirubic Acid in Sodium Taurocholate Solution", J. Chem. Soc. Perkin Trans. 2, 1998, 1677-82.
W. H. Schwesinger, W. E. Kurtin, C. P. Page, R. M. Stewart, and R. Johnson, "Soluble Dietary Fiber Protects Against Cholesterol Gallstone Formation", Am. J. Surgery, 177, 307-310, (1999).
K. D. Black*, S. Kothari*, P. A. Sharp*, J. W. Quesnel*, V. A. Escobar*, W. E. Kurtin, and M. M. Bushey, "Micellar Electrokinetic Chromatography of Bilirubin and Related Compounds in Unconjugated and Glyco-Conjugated Bile Salt Solutions", J. Liq. Chrom. & Rel. Technol., 23, 113-125, (2000).
C. Maeder*, G. Beaudoin*, E-kai Hsu*, V. Escobar*, W. E. Kurtin, and M. M. Bushey, "Measurement of Bilirubin Partition Coefficients in Bile Salt Micelle / Aqueous Buffer Solutions by Micellar Electrokinetic Chromatography", Electrophoresis, 21, 706-714, (2000).
W. E. Kurtin, J. Enz*, C. Dunsmoor*, N. Evans*, D. A. Lightner, "Acid Dissociation Constants of Bilirubin and Related Carboxylic Acid Compounds in Bile Salt Solutions", Arch. Biochem. Biophys., 81, 83-91, (2000).
W. E. Kurtin, W. H. Schwesinger, and A. K. Diehl, "Changes in Chemical Composition and Type of Gallstones Associated with Patient Age", Int. J. Surg. Invest., 2, 299-307, (2000).
W. E. Kurtin and J. M. Lee, "The Free Energy of Denaturation of Lysozyme",
Biochemistry and Molecular Biology Education, 30(4), 244-247, (2002).
