Structure and property of self-assemble valinyl bolaform amides having different chirality.
Bolaform amides were designed from N,N'-bis(carboethoxy-L-valinyl)-diaminoethane (1) by linking t-butyloxycarbonyl-valine through ethylenediamine (EDA) to enable spectroscopic and X-ray diffraction analyses. N,N'-Bis(Boc-L-valinyl)-diaminoethane (2) and N,N'-bis(Boc-D-valinyl)-diaminoethane (3) were composed of L-Val and D-Val, respectively. N-(Boc-L-valinyl)-N'-(Boc-D-valinyl)-diaminoethane (4) was composed of both L-Val and D-Val, and was achiral (meso-peptide). Peptide 5 was a 1:1 mixture of 2 and 3, and was also achiral (racemate). These peptides mediated gelation of corn oil at a concentration of approximately 1%. Within crystals, the peptides formed beta-sheet ribbons, but differences were observed in hydrogen-bonding patterns and side-chain arrangements. These differences were also deduced from temperature dependence of amide protons. Force-field calculations based on the crystal structures indicated that association of beta-sheet ribbons had energy benefits, and it was assumed that molecular aggregation progressed spontaneously. These structural studies indicated the chirality of amino acids affected for the properties of bolaform amides.
Doi
M
M
Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan. doit@gly.oups.ac.jp
Asano
A
A
Yoshida
H
H
Inouguchi
M
M
Iwanaga
K
K
Sasaki
M
M
Katsuya
Y
Y
Taniguchi
T
T
Yamamoto
D
D
D000577:Amides / Q000138:chemical synthesis / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D018360:Crystallography, X-Ray; D005233:Fatty Alcohols; D008855:Microscopy, Electron, Scanning; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
D000577:Amides; D000596:Amino Acids; D005233:Fatty Alcohols; D010455:Peptides; C029383:n-decyl alcohol