Control of the spatial organization of proteinogenic side chains is critical for the development of protein mimics with selective recognition properties toward target protein surfaces. We present a novel methodology for producing a linear array of proteinogenic residues based on the incorporation of alpha-amino acids into sequences of rigid, helically folded oligoamides of 8-amino-2-quinolinecarboxylic acid (Q). When l-leucine (L) was alternated with dimer Q(2), the resulting sequence adopted a right-handed helical conformation, as deduced in solution from the CD spectra of L-(LQ(2))(n) (n = 2, 4) and in the solid state from X-ray crystallographic analysis of (+/-)-(LQ(2))(4). Each LQ(2) segment spanned just one helix turn (pitch of 3.5 angstrom), and consequently, the four leucine side chains of (LQ(2))(4) formed a linear array. In solution, NMR analysis showed that both L-(LQ(2))(2) and L-(LQ(2))(4) exist as a mixture of two slowly equilibrating folded conformers, the proportion of which strongly varies with the solvent.