| Project/Area Number |
06302085
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 総合 |
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| Research Field |
Biophysics
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| Research Institution | Saitama University |
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Principal Investigator |
HUSIMI Yuzuru Saitama University, Engineering, Professor, 工学部, 教授 (80011641)
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| Co-Investigator(Kenkyū-buntansha) |
YANAGAWA Hiroshi Mitsubishi Kasei Institute of Life Science, Group Leader, 生命科学研究所, 室長
MORISHIMA Isao Kyoto University, Engineering, Professor, 大学院・工学研究科, 教授 (50026093)
GO Michiko Nagoya University, Science, Professor, 大学院・理学研究科, 教授 (70037290)
URABE Itaru Osaka University, Engineering, Professor, 大学院・工学研究科, 教授 (60029246)
OSHIMA Tairo Tokyo Pharmaceutical University, Life Science, Professor, 生命科学部, 教授 (60167301)
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| Project Period (FY) |
1994 – 1996
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| Keywords | EVOLUTIONARY MOLECULAR ENGINEERING / EXPERIMENTAL EVOLUTION / IN VITRO EVOLUTION / SEQUENCE SPACE / ADAPTIVE WALK / FITNESS LANDSCAPE / MODULE SHUFFLING / THERMOSTABILIZED ENZYME |
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| Research Abstract |
1.A theory of the ideal fitness landscape on the multi-valued sequence space was constructed. Many experimental data agreed to this theory and showed the landscapes are near Mt.Fuji-type. Overall landscape of an enzyme for multi-step reaction is proved to be also near Mt.Fuji-type. 2.Virus-type strategy for the genotype/phenotype linking could drive the origin of the translational system. Efficiency and design principle of in vitro virus are shown. 3.Local landscape around catalase wild type sequence were investigated and it was shown that the landscape of thermal stability is single-peak but the landscape of catalytic activity is rugged and is superimposed with peroxidase activity. When random peptide was added to the C-terminus of the enzyme, the fitness was improved. 4.Taking a chimera enzyme between E.coli and thermofile as the starting sequence, the evolutionary optimization of thrmal stability of the enzyme were performed. Analysis of advantageous mutants revealed the molecular m
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echanism of thermal stability and the enzyme from the thermofile was further thermo-stabilized. This demonstrated the advantage of evolutionary approach. 5.Classification of modules from various proteins was performed. It permitted the identification of the common module among functionally different proteins, for exnample, the DNA-phosphate-binding module. Mechanical stability of a module from barnase in water was shown with molecular dynamics calculation. It demonstrated the stability of the parts of proteins. 6.Quaternary-structural analysis of various chimera globins constructed by replacement of the module M4 with the M4 from a different globin showed that a module is a unit of structure and function. 7. "Multirecombinant PCR" method was developed for the module shuffling. 8. "Competitive coexistence" was discovered in the competitive continuous culture of E.coli mutants due to complex interactions between mutants. 9.Spontaneous diversification, stability in population-level and recursive multiplication were shown to emerge in an interactively growing population with internal states through computer simulation Less
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