Vibrational spectroscopic studies on Ca2+-binding function of Ca2+-binding proteins

2016 Fiscal Year Final Research Report

• Project/Area Number: 26410005
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: Nara Masayuki 東京医科歯科大学, 教養部, 教授 (90301168)
• Co-Investigator(Renkei-kenkyūsha): SAWANO Yoriko 東京医科歯科大学, 教養部, 准教授 (00571077)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 赤外分光 / カルシウム結合タンパク質 / 合成ペプチドアナログ / 配位構造 / 凝集

Outline of Final Research Achievements

Infrared spectroscopy (FTIR) was applied to study the synthetic peptide analogues corresponding to the EF-hand motif (helix-loop-helix) of rabbit skeletal muscle troponin C (site III), Nicotiana tabacum calmodulin (NtCaM) isoforms and carp parvalbumin pI 4.25 (CD and EF). We examined the 17-residue peptide analogues rabbit skeletal muscle troponin C (site III), where a side chain COO- group of Glu or Asp was labeled by 13C-nuclei. The 13C-labeled COO- group of Glu at the 12th position showed a band at 1526 cm-1 and 1518 cm-1 in the apo and the Ca2+-loaded states, respectively. We confirmed that the band at 1518 cm-1 was due to the 13C-labeled COO- group coordinated to the Ca2+ ion in the bidentate mode. We found that the bandwidth for the COO- group in the bidentate coordination mode was clearly narrower than that for that in the apo state. The implications of the 13C-labeled COO- antisymmetric vibration mode was discussed on the basis of density functional theory (DFT) calculation.

Free Research Field

生体分子分光学