- Molecular capture and conformational change of diketopiperazines containing proline residues by epigallocatechin-3-O-gallate in water
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The addition of an aqueous solution of diketopiperazine cyclo(Pro-Xxx) (Xxx: amino acid residue) to an aqueous solution of (?)-epigallocatechin-3-O-gallate (EGCg) led to precipitation of the complex of EGCg and cyclo(Pro-Xxx). The molecular capture abilities of cyclo(Pro-Xxx) using EGCg were evaluated by the ratio of the amount of cyclo(Pro-Xxx) included in the precipitates of the complex with EGCg to that of the total cyclo(Pro-Xxx) used. Stronger hydrophobicity of the side chain of the amino acid residue of cyclo(Pro-Xxx) led to a higher molecular capture ability. Furthermore, the molecular capture ability decreased when the side chain of the amino acid residue had a hydrophilic hydroxyl group. When diketopiperazine cyclo(Pro-Xxx), excluding cyclo(D-Pro-L-Ala), was taken into the hydrophobic space formed by the three aromatic A, B, and B′ rings of EGCg, and formed a complex, their conformation was maintained in the hydrophobic space. Based on nuclear Overhauser effect (NOE) measurement, the 3-position methyl group of cyclo(D-Pro-L-Ala) in D2O was axial, whereas that of cyclo(L-Pro-L-Ala) was equatorial. When cyclo(D-Pro-L-Ala) was taken into the hydrophobic space of EGCg and formed a 2:2 complex, its 3-position methyl group changed from the axial position to the equatorial position due to steric hindrance by EGCg.
- Ishizu, Takashi,Tokunaga, Miku,Fukuda, Moeka,Matsumoto, Mana,Goromaru, Takeshi,Takemoto, Soushi
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p. 585 - 589
(2021/06/06)
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- Carboline-3-carboxylic acid modified related sequences of Ala-Arg-Pro-Ala-Lys, their synthesis and use as thromobolytic agent
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The present invention relates to the protected intermediates and the deprotected products of P6A, related to the protected pseudopeptides introducing the protected intermediateds of P6A to 3S-(2-Boc)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid and the deprotected pseudopeptides, related to the protected pseudopeptides introducing the protected intermediateds of P6A to 3S-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid benzyl ester, related to the methods for their preparation, and related to their use as the thrombolytic agents.
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Page/Page column 11
(2010/02/11)
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- Synthesis and Biological Properties of New Hexapeptide Substrates for Vitamin K Dependent Carboxylase. Evidence for X-Pro Cis/Trans Amide Bond Interconversions in Prothrombin Precursor Fragment 18-22
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Three hexapeptide analogues, corresponding to sequence 18-23 of bovine prothrombin precursor > have been synthesized and evaluated as substrates for vitamin K dependent carboxylase.These new hexapeptides are moderately good substrates for the ca
- Rich, Daniel H.,Kawai, Megumi,Goodman, Hedda L.,Suttie, John W.
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p. 910 - 916
(2007/10/02)
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