G Pietrzyński, B Rzeszotarska, E Ciszak, M Lisowski, Z Kubica, G Boussard
{"title":"脱氢肽的构象研究。7Ac-Pro- deltaala - nhch3和Ac-Pro-(E)- deltaabu - nhch3的构象:与(Z)取代的-脱氢肽的比较。","authors":"G Pietrzyński, B Rzeszotarska, E Ciszak, M Lisowski, Z Kubica, G Boussard","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>The crystal structure and solution conformation of Ac-Pro-deltaAla-NHCH3 and the solution conformation of Ac-Pro-(E)-deltaAbu-NHCH3 were investigated by X-ray diffraction method and NMR, FTIR and CD spectroscopies. Ac-Pro-deltaAla-NHCH3 adopts an extended-coil conformation in the crystalline state, with all-trans peptide bonds and the deltaAla residue being in a C5 form, phi(1)=-71.4(4), psi(1)=-16.8(4), phi(2)= -178.4(3) and psi(2)= 172.4(3) degrees. In inert solvents the peptide also assumes the C5 conformation, but a gamma-turn on the Pro residue cannot be ruled out. In these solvents Ac-Pro-(E)-deltaAbu-NHCH3 accommodates a beta(II)-turn, but a minor conformer with a nearly planar disposition of the CO-NH and C=C bonds (phi(2) approximately 0 degrees) is also present. Previous spectroscopic studies of the (Z)-substituted dehydropeptides Ac-Pro-(Z)-deltaAbu-NHCH3 and Ac-Pro-deltaVal-NHCH3 reveal that both peptides prefer a beta(II)-turn in solution. Comparison of conformations in the family of four Ac-Pro-deltaXaa-NHCH3 peptides let us formulate the following order of their tendency to adopt a beta-turn in solution: (Z)-deltaAbu > (E)-deltaAbu > deltaVal; deltaAla does not. None of the folded structures formed by the four compounds is stable in strongly solvating media.</p>","PeriodicalId":14204,"journal":{"name":"International journal of peptide and protein research","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Conformational investigation of alpha,beta-dehydropeptides. VII. Conformation of Ac-Pro-deltaAla-NHCH3 and Ac-Pro-(E)-deltaAbu-NHCH3: comparison with (Z)-substituted alpha,beta-dehydropeptides.\",\"authors\":\"G Pietrzyński, B Rzeszotarska, E Ciszak, M Lisowski, Z Kubica, G Boussard\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The crystal structure and solution conformation of Ac-Pro-deltaAla-NHCH3 and the solution conformation of Ac-Pro-(E)-deltaAbu-NHCH3 were investigated by X-ray diffraction method and NMR, FTIR and CD spectroscopies. Ac-Pro-deltaAla-NHCH3 adopts an extended-coil conformation in the crystalline state, with all-trans peptide bonds and the deltaAla residue being in a C5 form, phi(1)=-71.4(4), psi(1)=-16.8(4), phi(2)= -178.4(3) and psi(2)= 172.4(3) degrees. In inert solvents the peptide also assumes the C5 conformation, but a gamma-turn on the Pro residue cannot be ruled out. In these solvents Ac-Pro-(E)-deltaAbu-NHCH3 accommodates a beta(II)-turn, but a minor conformer with a nearly planar disposition of the CO-NH and C=C bonds (phi(2) approximately 0 degrees) is also present. Previous spectroscopic studies of the (Z)-substituted dehydropeptides Ac-Pro-(Z)-deltaAbu-NHCH3 and Ac-Pro-deltaVal-NHCH3 reveal that both peptides prefer a beta(II)-turn in solution. Comparison of conformations in the family of four Ac-Pro-deltaXaa-NHCH3 peptides let us formulate the following order of their tendency to adopt a beta-turn in solution: (Z)-deltaAbu > (E)-deltaAbu > deltaVal; deltaAla does not. None of the folded structures formed by the four compounds is stable in strongly solvating media.</p>\",\"PeriodicalId\":14204,\"journal\":{\"name\":\"International journal of peptide and protein research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1996-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International journal of peptide and protein research\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International journal of peptide and protein research","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Conformational investigation of alpha,beta-dehydropeptides. VII. Conformation of Ac-Pro-deltaAla-NHCH3 and Ac-Pro-(E)-deltaAbu-NHCH3: comparison with (Z)-substituted alpha,beta-dehydropeptides.
The crystal structure and solution conformation of Ac-Pro-deltaAla-NHCH3 and the solution conformation of Ac-Pro-(E)-deltaAbu-NHCH3 were investigated by X-ray diffraction method and NMR, FTIR and CD spectroscopies. Ac-Pro-deltaAla-NHCH3 adopts an extended-coil conformation in the crystalline state, with all-trans peptide bonds and the deltaAla residue being in a C5 form, phi(1)=-71.4(4), psi(1)=-16.8(4), phi(2)= -178.4(3) and psi(2)= 172.4(3) degrees. In inert solvents the peptide also assumes the C5 conformation, but a gamma-turn on the Pro residue cannot be ruled out. In these solvents Ac-Pro-(E)-deltaAbu-NHCH3 accommodates a beta(II)-turn, but a minor conformer with a nearly planar disposition of the CO-NH and C=C bonds (phi(2) approximately 0 degrees) is also present. Previous spectroscopic studies of the (Z)-substituted dehydropeptides Ac-Pro-(Z)-deltaAbu-NHCH3 and Ac-Pro-deltaVal-NHCH3 reveal that both peptides prefer a beta(II)-turn in solution. Comparison of conformations in the family of four Ac-Pro-deltaXaa-NHCH3 peptides let us formulate the following order of their tendency to adopt a beta-turn in solution: (Z)-deltaAbu > (E)-deltaAbu > deltaVal; deltaAla does not. None of the folded structures formed by the four compounds is stable in strongly solvating media.