| Project/Area Number |
17350080
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Chemistry related to living body
|
|---|
| Research Institution | Ibaraki University |
|---|
Principal Investigator |
NIIMURA Nobuo Ibaraki University, Graduate School of Science and Engineering, Professor (50004453)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TANAKA Ichiro Ibaraki University, College of Engineering, Assistant Professor (20354889)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥14,170,000 (Direct Cost: ¥13,600,000、Indirect Cost: ¥570,000)
Fiscal Year 2007: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2006: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2005: ¥9,900,000 (Direct Cost: ¥9,900,000)
|
|---|
| Keywords | neutron protein crystallography / structural biological chemistry / methyl group / confguration / mvoglobin / rubredoxin / hydrog+C601en bond / lone pair / エクリプス / スタガード / ニューマン投影 / 中性子回折 / 中性子構造生物 / 水素 / タンパク質 / ねじれ配座 / 重なり配座 / 中性子タンパク質構造解析 / 水和構造 / 双極子モーメント場 / 水素結合強度 / タンパク質化学結合 / タンパク質結晶成長 |
|---|
| Research Abstract |
Methyl CH_3 group configuration
In gaseous ethane, C-C bond rotates freely but a staggered conformation is most stable and an eclipsed conformation is most unstable. Our high-resolution neutron diffraction analyses of myoglobin and other proteins have provided this information. The hydrogen atoms of alanine and isoleucine in rubredoxin are clearly identified. All the CH_3 group configurations in amino acid residues are extracted and discussed. It is found that most of the CH_3 groups belong to the stable staggered conformations (angles close to 60°), but several % of them appear to have values close to eclipsed conformations (defined by angles close to 0°).
Non-linear hydrogen bonds
In the neutron analysis of the α-helices of myoglobin, the linearity of the X-H…Y hydrogen bonds has been analyzed. The statistics of hydrogen bonds N-H…O=C of the α-helices of myoglobin have been obtained, where the length between H and O is r and the NHO and COH angles are θ_1, and θ_2, respectively. The non-linearity of the actual N-H…O bond angle θ_1 is correlated to the deviation of H…O=C angles θ_2 from the value of 120° normally expected for the lone pair electrons of an sp^2-hydridized carbonyl oxygen. It seems that the steric constraints imposed by the packing of atoms in a protein molecule, in this case an α-helix, necessitates considerable deviation normally found in small-molecule structures.
|
