TY - JOUR
T1 - Pressure perturbation calorimetry of helical peptides
AU - Barrett, Devin G.
AU - Minder, C. Michael
AU - Mian, Michele U.
AU - Whittington, Shelly J.
AU - Cooper, W. John
AU - Fuchs, Kristin M.
AU - Tripathy, Ashutosh
AU - Waters, Marcey L.
AU - Creamer, Trevor P.
AU - Pielak, Gary J.
PY - 2006/5/1
Y1 - 2006/5/1
N2 - Pressure perturbation calorimetry quantifies the temperature dependence of a solute's thermal expansion coefficient, providing information about solute-solvent interactions. We tested the idea that pressure perturbation calorimetry can provide information about solvent-accessible surface area by studying peptides with different secondary structures. The peptides comprised two host-guest series: one predominately an α-helix, the other predominately a polyproline II helix. In aqueous buffer, we find a correlation between the amount of secondary structure as assessed by circular dichroism spectropolarimetry and the pressure perturbation calorimetry data. We conclude that pressure perturbation calorimetry can provide information about the exposure of polar and nonpolar surface area. Data acquired in a buffered urea solution, however, are not as easily interpreted.
AB - Pressure perturbation calorimetry quantifies the temperature dependence of a solute's thermal expansion coefficient, providing information about solute-solvent interactions. We tested the idea that pressure perturbation calorimetry can provide information about solvent-accessible surface area by studying peptides with different secondary structures. The peptides comprised two host-guest series: one predominately an α-helix, the other predominately a polyproline II helix. In aqueous buffer, we find a correlation between the amount of secondary structure as assessed by circular dichroism spectropolarimetry and the pressure perturbation calorimetry data. We conclude that pressure perturbation calorimetry can provide information about the exposure of polar and nonpolar surface area. Data acquired in a buffered urea solution, however, are not as easily interpreted.
KW - Circular dichroism
KW - Coefficient of thermal expansion
KW - Polyproline II helix
KW - Pressure perturbation calorimetry
KW - Secondary structure
KW - α-helix
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U2 - 10.1002/prot.20819
DO - 10.1002/prot.20819
M3 - Article
C2 - 16372358
AN - SCOPUS:33645276812
SN - 0887-3585
VL - 63
SP - 322
EP - 326
JO - Proteins: Structure, Function and Genetics
JF - Proteins: Structure, Function and Genetics
IS - 2
ER -