Conformations of cis‐ and trans‐2, 3‐methanomethionine stereoisomers in the tripeptide mimic system Ac{cyclo‐M}NHiPr Academic Article uri icon

abstract

  • Quenched molecular dynamics (QMD) was used to simulate low-energy conformers of the tripeptide mimics Ac¿cyclo-Met¿NHiPr, where the 2.3-methanomethionine is the cis-derivative (2R,3S)-cyclo-Met and the trans-derivative (2R,3R)-cyclo-Met. Variations of the favored omicron, upsilon values. and differences between the simulated preferred conformations for the two structures, were rationalized and discussed. Physical data for the cis-derivative (NMR, CD and FT-IR) gave no conclusive evidence for any preferred conformation. However for the trans-derivative, Ac¿(2R,3R)-cyclo-Met¿NHiPr, the physical data suggests that a conformer with partial helical structure is favored. This work provides details of how the rigidly constrained side chain and cyclopropane of 2,3-methanoamino acids can be used to manipulate phi, psi values in a logical fashion.

author list (cited authors)

  • BURGESS, K., & KE, C.

citation count

  • 8

publication date

  • March 1997

publisher