Preparation and Conformational Properties of Benzylpenicilloyl‐oligo‐L‐lysine Conjugates

Abstract

SummarySelected oligo-L-lysine carriers and a poly-L-lysine were penicilloylated with benzylpenicillin. The resulting conjugates 2-6 were studied by IR. absorption in the solid state and circular dichroism measurements in solution. The IR. data demonstrate the lack of /3-structure formation even in medium-sized peptides where such structures might be expected on the basis of previous studies on differen tly substituted oligo-L-lysines. Considerable proportions of right-handed a-helical conformation are exhibited by the icosa-L-lysine and poly-L-lysine conjugates 5 and 6 in water and 2,2,2-trifluoroethanol. Difficulties in obtaining fully penicilloylated conjugates are not related to the extent of a-helical conformation in aqueous solution.