Theoretical conformational analysis of methylamide of N-acetyl-L-lysine.

The spatial structure of the methylamide of N-acetyl-L-lysine has been analysed taking into account non-bonded and electrostatic interactions, torsional energy, bond angles distortion and hydrogen bonding. Conformational capacities of the backbone and mutual dependence of spatial structures of the backbone and the side chain was described by conformational maps obtained by energy minimisation, the dihedral angles and the bond angles of the side chain being varied for every phi, psi point. Every possible combination for phi, psi, x1-x5-angles was used corresponding to the stable form of the backbone and to torsion potential minima of the initial approximations in the calculation of preferred conformations of the molecule. Comparisons are made between stable forms of the methylamide of N-acetyl-L-lysine and Lys residues in proteins with known structure.