Precise Heat Capacity Measurement of Dilute Protein Aqueous Solutions by AC-Calorimetry

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 07458172
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Biophysics
• Research Institution: Osaka Prefecture University
• Principal Investigator: TAKAHASHI Katsutada College of Agriculture, Osaka Prefecture University, Preofessor, 農学部, 教授 (30081532)
• Co-Investigator(Kenkyū-buntansha): NISHIMURA Shigenori College of Agriculture, Osaka Prefecture University, Research Associate, 農学部, 助手 (90244665) ; HIBINO Takeshi College of Agriculture, Osaka Prefecture University, Research Associate, 農学部, 助手 (30221518) ; FUKADA Harumi College of Agriculture, Osaka Prefecture University, Associate Preofessor, 農学部, 助教授 (50128774) ; NITTA Yasunori College of Agriculture, Osaka Prefecture University, Preofessor, 農学部, 教授 (30081574)
• Project Period (FY): 1995 – 1997
• Keywords: AC-calorimetry / proteins / heat capacity measurement / specific heat / DSC / differential scanning calorimeter / thermodynamic stability

Research Abstract

In order to establish a method to heat capacity of native and denatured proteins in aqueous dilute solution and to determine their thermodynamic stability, an AC-calorimeter was designed and constructed. Testing was performed on the aqueous solutions of potassium chloride, urea, glucose, maltose and protein lysozyme.
Although the instrumental signal corresponding to the heat capacity was found to be proportional to the solute concentrations, its absolute magnitude contained fairly large errors resulting in the poor reproducibility. It was concluded that the design is not applicable to the practical measurement of the heat capacity of proteins in solution in its original form and some possible points to improve the method were discussed.