| Project/Area Number |
61550648
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Synthetic chemistry
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| Research Institution | Kumamoto Institute of Technology |
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Principal Investigator |
UEOKA Ryuichi Kumamoto Institute of Technology, 工学部, 助教授 (70099076)
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| Co-Investigator(Kenkyū-buntansha) |
MATAUMOTO Yoko Kumamoto Institute of Technology, 工学部, 副手 (00133562)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | enantioselectivity / amino acid ester / peptide catalyst / artificial enzyme / circular dichroism / steric control / artificial membrane / 人工細胞膜 / 酵素モデル / 分子集合体反応場 / モーホロジー制御 |
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| Research Abstract |
Streoselective cleavages of n-protected amino acid p-nitrophenyl esters in vesicular,micellar or coaggregate systems have been used as models to provide the originns of stereoselectivity in the proteolytic enzymes. Studies of enantioselectivity have emphasized the roles of hydrophobic interaction between catalyst and substrate,conformation of peptide catalysts and the structure of the aggregates.
The noteworyhy aspects are as follows:
1. The LLL-tripeptide N-(benxyloxy-carbony1)-L-Phenylalanyl-L-histidyl-L-leucine (Z-Phehisleu) was most efficient for the enhancement of enantioselectivity for the hydrolysis of p-nitrophenyl Ndodecanoyl-D(L)-phenylalaninate (D(L)-s_<12>) among all thepeptide catalysts employed in this study.
2. With respect to the reaction of D(L)-S_<12>with Z-PheHisLeu, excellent correlations were obtained between the stereoselectivity and the apparent mean hydrodynamic diameters of cationic coaggregates composed of vesicular and micellar surfactants.
3. On the basis of the circular dichroism (CD) experiments, Z-PheHisLeu has a possibility to constitute a hydrophobic pecket through the intramolecular interactions between the side chains of the Phe,His,and Leu residues. As regards the remarkably high enantioselectivity,it is suggested that the adjusting of the hydrophobic microenvironment to optimum fit of Z-Phe-HisLeu and L-s_<12> by changing the composition of coaggregates could be a very important factor along wqith the favorable fitting of reactants like"Key and lock" as demonstrated in the space-filling molecular model (CPK model),and subsebuently,the adjusting of the hydrophobic microenbironment to the optimum fit of reactants by changing appropriately the composition of cosggregates would induce the highest enantioselectivity.
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