281669-40-7Relevant articles and documents
Comparative conformational analysis of peptides based on the two Ca-tetrasubstituted, Cβ-branched, chiral α-amino acids (αMe) Dip and (αMe)Val
Lapena, Yolanda,Lopez, Pilar,Cativiela, Carlos,Kaptein, Bernard,Broxterman, Quirinus B.,Kamphuis, Johan,Mossel, Eric,Peggion, Cristina,Formaggio, Fernando,Crisma, Marco,Toniolo, Claudio
, p. 631 - 636 (2007/10/03)
For the first time a number of terminally protected model peptides (to the pentamer level) of the sterically demanding α-amino acid Cα-methyl, Cα-diphenylmethylglycine, (αMe)Dip, in combination with either Ala or Gly residues, have been synthesized (by solution methods) and fully characterized. In a parallel synthesis the corresponding peptides based on the related α-amino acid Cα-methyl, Cα-isopropylglycine, (αMe)Val, have also been prepared. The results of a comparative conformational analysis, performed by using FTIR absorption, 1H NMR, and X-ray diffraction techniques, favour the conclusion that, in contrast to the potent β-turn and 310-helix promoter (αMe)Val, (αMe)Dip may induce either a folded or a fully extended conformation. These findings indicate that, despite the common Cα-methylated and Cβ-branched features, (αMe)Dip and (αMe)Val are characterized by partially divergent conformational bias.