Professor of Chemistry
Ph.D. Harvard University
Graduate School of Arts and Sciences
M.A. Harvard University
B.A. Wheaton College
The relationship between structure and function of proteins. Favorite proteins over 25 years: aspartate transcarbamylase (ATCase), myosin, and alkaline phosphatase (AP).
The stability of protein structure. In recent years we have investigated the stability of the protein fold using Treansverse Urea Gradient Gel Elecrophoresis (Creighton gels). Recent efforts have focused on genetically engineered mutants of alkaline phosphatase (AP), for which we demonstrated that impaired interactions at the dimer interface resulted in a global destabilization of the protein fold.
While on sabbatical in France I examined the relationship between thermostability and barostability in the ATCase of the extremophilic archaeobacteria Pyrococcus furiosus and Pyrococcus abyssi. More definitive experimental results gathered in 2001 and 2002 have led to the conclusion that the molecular strategies that make proteins resistant to high heat also render them stable to high pressures. A new discovery has been the observation that the ATCase of these thermophilic bacteria improves its enzymatic activity when treated at high temperatures first; in this behavior it differs from all conventional proteins.
At Wheaton, Lauren Dufort '00, Selam Berhane '01, and Jennifer Schefiliti '03 have investigated the effect of active-site-bound metals on the folding stability of AP. This work is still in progress.
I enjoy teaching at all levels, and have taught the courses in General Principles, Organic Chemistry, Advanced Organic Chemistry and the Senior Seminar. Interactions with students in the laboratory are among the most rewarding teaching hours for me. In the spring of 2004 I am teaching "Edible Chemicals", a new course developed for students who are not majoring in science; it forms part of the "Food" connection.
Bach, distance running (five marathons so far) and scuba diving in warmer waters. I use any time I can find for reading, and would be a cinema-addict if there were enough hours in the week. I travel with my family whenever possible, most frequently to Greece, my original homeland.
Minic, Z., Pastra-Landis, S., Gaill, F. and Hervé, G. (2001) "Catabolism of Pyrimidine Nucleotides in the Deep-Sea Tube Worm Riftia pachyptila," J. Biol. Chem., 313, 101074-101083.
Pastra-Landis, S.C. and Herve, G. (1999) "Are Thermostable Proteins Rendered Intrinsically Barostable? The Aspartate Transcarbamylase of Pyrococcus furiosus Compared to that of Pyrococcus abyssi." Presented at the 15th International ATCase Workshop, in Waterloo, Belgium, June, 1999.
Martin, D. C., Pastra-Landis, S.C. and Kantrowitz, E. R. (1999) "Amino Acid Substitutions at the Subunit Interface of Dimeric E. coli Alkaline Phosphatase Cause Reduced Structural Stability," Protein Science, 8, 1152-1159.
Saraswat, L., Pastra-Landis, S.C. and Lowey, S. (1992) "Mapping Single Cysteine Mutants of Light Chain-2 in Chicken Skeletal Myosin," J. Biol. Chem., 267, 21112-21118.
Pastra-Landis, S.C. and Lowey, S. (1986) "Myosin Subunit Interactions; Properties of the 19,000-Dalton Light Chain-Deficient Myosin," J. Biol. Chem., 261, 14811-14816.
Lee, L., Kelly, R.E., Pastra-Landis, S.C. and Evans, D.R. (1985) "Oligomeric Structure of the Multifunctional Protein CAD that Initiates Pyrimidine Biosynthesis in Mammalian Cells," Proc. Natl. Acad. Sci. USA, 82, 6802-6806.
Pastra-Landis, S.C., Foote, J., and Kantrowitz, E.R. (1981) "An Improved Colorimetric Assay for Aspartate and Ornithine Transcarbamylases," Analytical Biochemistry, 118, 358-363.
Pastra-Landis, S.C., Evans, D.R., and Lipscomb, W.N. (1978) "The Effect of pH on the Cooperative Behavior of Aspartate Transcarbamylase," J. Biol. Chem., 253, 4624-4630.
Evans, D.R., Pastra-Landis, S.C. and Lipscomb, W.N. (1975) "Isolation and Properties of a Species Produced by the Partial Dissociation Aspartate Transcarbamylase from E. coli," J. Biol. Chem., 250, 3571-3583.
Ancient publication derived from independent research conducted when I was an undergraduate at Wheaton College:
Jennings, B.H., Pastra, S.C. and Wellington, J.L. (1970) "Photosensitized Dimerization of Thymine," Photochem. Photobiol., 11, 215-226.
Presentations, with students, in recent conferences over the last five years:
With Stephen Benz '05,
Pastra-Landis, S. C., Benz S. and Hervé, G. (2002) "Thermostability Confers Barostability in Aspartate Trancarbamylase from Archaea." Presented at the 18th International ATCase Workshop, in Paris, France, June, 2002.
Pastra-Landis, S. C., Benz S. and Hervé, G. (2002) "Protein Survival Under Heat and Pressure." Presented at the Third International REU/IGERT Meeting, Strasbourg, France, June, 2002.
Pastra-Landis, S. C., Benz S. and Hervé, G. (2002) "Studies on the Thermostability and the Barostability of Aspartate Transcarbamoylase from Archaea." Presented at the 224th American Chemical Society National Meeting, Boston, Massachusetts, August, 2002.
With Selam Berhane '01 and Stephanie Drobiak '01,
Berhane, S. and Pastra-Landis, S. (2001) "Studies on the Folding of Alkaline Phosphatase from E. coli." Presented at the Third Annual Northeast Student Chemistry Research Conference at Boston University, Boston, Massachusetts, April, 2001.
Drobiak S. and Pastra-Landis, S. (2001) "Characterization of the Enzyme Aspartate Transcarbamylase from the Archaeon Pyrococcus furiosus." Presented at the Third Annual Northeast Student Chemistry Research Conference at Boston University, Boston, Massachusetts, April, 2001.
With Lauren Dufort '00,
Dufort, L. L. and Pastra-Landis, S. C. (2000) "The Role of Metals in Alkaline Phosphatase Folding." Presented at the Northeast Student Chemistry Research Conferece, Massachusetts Institute of Technology, Cambridge, Massachusetts, April 29, 2000.
With Lauren Dufort and Donna Carolan Martin,
Pastra-Landis, S. C., Dufort, L. Martin, D. C. and Kantrowitz, E.R. (1999) "The Effects of Metal Ions and Phosphate on the Unfolding of E. coli Alkaline Phosphatase." Presented at the Thirteenth Symposium of the Protein Society in Boston, Massachusetts, July 1999.
With Amy LaChance and Donna Carolan,
Pastra-Landis, S. C., Carolan, D., LaChance, A. E. and Kantrowitz, E.R. (1997) "The Folding of E. coli Alkaline Phosphatase Examined by Transverse Urea Gel Electrophoresis." Presented at the Eleventh Symposium of the Protein Society in Boston, Massachusetts, July 1997.
With Amy LaChance and Donna Carolan,
Pastra-Landis, S. C., Carolan, D., LaChance, A. E. and Kantrowitz, E.R. (1997) "Interface Mutants of E. coli Alkaline Phosphatase Investigated by Transverse Urea Gel Electrophoresis." Presented at the Second European Symposium of the Protein Society in Cambridge, England, April 1997.