Synthesis and conformational properties of polypeptides containing long aliphatic side chains. Poly(N-epsilon-stearyl-L-lysine) and poly(N-epsilon-pelargonyl-L-lysine).

Poly(Nε‐stearyl‐L‐lysine) and poly(Nε‐pelargonyl‐L‐lysine) were synthesized both by polymerization of Nε‐pelargonyl and Nε‐stearyl‐L‐lysine NCA and by acylation of poly(L‐lysine) with pelargonyl and stearyl chloride. This second route has proven to be very useful, since completely acylated polymers are obtained in almost quantitative yield, whereas the usual scheme of preparation of ε protected poly(L‐lysine) cannot easily be applied due to solubility problems. Poly(Nεpelargonyl and stearyl‐L‐lysine) are soluble in alcohols containing linear aliphatic chains such as n‐butanol and n‐octanol and in mixtures of these alcohols with hydrocarbons such as n‐hexane and n‐heptane. Both polymers show an α‐helical conformation in the above solvents, which can be disrupted upon addition of sulfuric acid. Also in the solid state, poly(Nε‐stearyl‐L‐lysine) and poly(Nε‐pelargonyl‐L‐lysine) show X‐ray diffraction patterns typical of order structure. Copyright © 1975 John Wiley & Sons, Inc.