ALKYLATED POLY(AMINO ACIDS) .1. CONFORMATIONAL PROPERTIES OF POLY(N-EPSILON-TRIMETHYL-L-LYSINE) AND "POLY(N-DELTA-TRIMETHYL-L-ORNITHINE)

Poly(Nε‐trimethyl‐L‐lysine), [Lys(Me3)]n, and poly(Nδ‐trimethyl‐L‐ornithine), [Orn(Me3)]n, in sodium dodecylsulfate do not assume the β‐structure or α‐helix, respectively, of their parent polymers. In 0.5M Ca(ClO4)2 both [Lys(Me3)]n and [Orn(Me3)]n are aggregated and display CD spectra indicative of a regular, perhaps helical, structure. For [Lys]n and [Lys(Me3)]n, the T1 of the α‐hydrogens are 0.379 and 0.230 sec, respectively, indicating greater rigidity for [Lys(Me3)]n. The CD spectrum of [Lys(Me3)]n at pH 8 is more heat resistant than that of [Lys]n. It is suggested that apolar interactions are more important in the methylated polymers than in the parent polymers. Copyright © 1979 John Wiley & Sons, Inc.