Thermodynamic of the reconstitution of protein structure from peptide fragments.

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 09680660
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Biophysics
• Research Institution: Kwansei Gakuin University
• Principal Investigator: SEGAWA Shin-ichi Kwansei Gakuin University, School of Science, Professor, 理学部, 教授 (70103132)
• Project Period (FY): 1997 – 1999
• Keywords: Cytochrome c / Peptide fragment-complex / Thermodynamics / Protein folding / Calorimetry

Research Abstract

Two peptide fragments from tuna cytochrome c, (1-44)H [H means that the fragment contains heme] and (45-103), combine to from a 1 : 1 fragment complex. This was clearly proved by ion-spray mass spectrometry. CD and NMR spectra showed that the structure of the fragment complex formed is similar to that of on intact cytochrome c, although each isolated fragment itself is unstructured. Binding constants and enthalpies upon the complex formation were directly observed by isothermal titration calorimetry. The change in enthalpy upon the complex formation was somewhat larger than that upon protein folding, because of the electrostatic attractive interactions between the amino group of N-terminus of (45-103) and heme propionates. When the electrostatic force was reduced by the addition of KCI, the enthalpy change become to coincide with each other.
In addition, smaller peptide fragments were prepared to investigate the effect of the losing some peptide segment from the whole amino acid sequence of protein. Prepared peptide fragments were (1-21)H, (22-44), (45-66) and (67-103). Calorimetric and spectroscopic experiments showed that the peptide segment (45-66) is important for the formation of energetically stable structure between N- and C-terminal helices.

Research Products

• [Publications] Noda Yasuo: "A Two-dimensional NMR study of exchange behavior of amide hydrogens in a Lysozyme derivative with an extra cross-link between Glu35 and Trp108"Biopolymers. 41. 131-143 (1997)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Kubo Shigeru: "Improvement in the oxidative folding of endothelin-1 by a Lys-Arg extension at the amino terminus"Letters in Peptide Science. 4. 185-192 (1997)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Yokota Atsushi: "Thermodynamics of the reconstitution of tuna Cytochrome c from two peptide fragments"Protein Science. 7. 1717-1727 (1998)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Yokota Atsushi: "The transition state in the folding-unfolding reaction of four Species of three-disulfide variant of hen lysozyme"J. Mol. Biol.. 295. 1275-1288 (2000)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Noda, Y. , Fukuda, Y. & Segawa, S.: ""A Two-Dimensional NMR Study of Exchange Behavior of Amide Hydrogens in a Lysozyme Derivative with an Extra Cross-Link Between Glu35 and Trp 108""Biopolymers. 41. 131-143 (1997)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Kubo, S., Chino, N., Nakajima, K., Aumelas, A., Chiche, L., Segawa, S., Tamaki, H., Kobayashi, Y., Kimura, T. & Sakakibara, S.: ""Improvement in the oxidative folding of endothelin-1 by a Lys-Arg extension at the amino terminus""Letters in Peptide Science. 4. 185-192 (1997)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Yokota, A., Takenaka, H., Oh, T., Noda, Y. & Segawa, S.: ""Thermodynamics of the reconstitution of tuna cytochrome c from two peptide fragments""Prptein Science. 7. 1717-1727 (1998)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Yokota, A., Izutani, K., Takai, M., Kubo, Y., Noda, Y., Koumoto, Y., Tachibana, H. & Segawa, S.: ""The Transition State in the Folding-Unfolding Reaction of Four Species of Three-disulfide Variant of Hen Lysozyme""J. Mol. Biol.. 295. 1275-1288 (2000)
  • Description: 「研究成果報告書概要(欧文)」より