| Project/Area Number |
18380067
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied biochemistry
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| Research Institution | Kyoto University |
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Principal Investigator |
MIKAMI Bunzo Kyoto University, Graduate School of Agriculture, Professor (40135611)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥12,490,000 (Direct Cost: ¥11,500,000、Indirect Cost: ¥990,000)
Fiscal Year 2007: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2006: ¥8,200,000 (Direct Cost: ¥8,200,000)
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| Keywords | nanobio / enzyme / protein eneineering / mobile loop / X-ray crystal analysis |
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| Research Abstract |
In order to clarify the role of mobile loops in food related enzymes and food proteins, the mobile loops of the enzymes such as β-amylase, alginate lyase and pullulanase and that in seed globulins were detected and investigated by X-ray crystallography. The flexible loop in the active site of b-amylase was extensively studied by mutation and high resolution X-ray crystallography at 1.0-1.3 A resolution. The X-ray analysis of 10 mutants/maltose complexes in the different maltose concentration revealed the importance of Asp101 both on the loop movement and substrate recognition. The motion of a lid loop in the active site of alginate lyase was investigated by using several crystal forms. The lid loop was mobile only in a orthorhombic crystal. The structure of alginate lyase/substrate complex refined at 2.0 A resolution together with the mutation study clearly revealed several residues of lid loop important for substrate recognition. Based on this closed lid loop structure, the enzymatic mechanism of alginate lyase was presented. Except for (β-amylase and alginate lyase, we have determined the structures of pullulanase, xanthan lyase, α-L-rhamnosidase and UDP-N-acetylglucosamine enolpyruvyl transferase in order to clarify the role of their mobile loops. On the other hand, in order to investigate the invisible mobile loop of plant 118 globulin, the homologous structure of 8S mungbean globulin was determined by X-ray analysis. The present studies strongly revealed the effectiveness of X-ray crystal analysis for the studies of mobile loops in food related enzymes and proteins.
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