Insertion of an internal dipeptide into PNA oligomers: thermal melting studies and further functionalization.
The solid phase synthesis of PNA oligomers with the internal dipeptide Gly-Phe is presented and the interaction with complementary DNA investigated. UV absorbance melting experiments with different but complementary DNA sequences show that stable PNA x DNA duplexes are only obtained when there is no DNA base opposite the dipeptide unit. Instead, the dipeptide spacer forms a loop-like structure within the duplex. Further functionalization with N-heterocyclic ligands is described. p-Nitro-phenylalanine is introduced in place of Phe during solid phase synthesis and subsequently reduced to p-amino-phenylalanine. Reaction with activated acids provides the ligand conjugates in high yield and purity. This strategy opens a universal route to a large number of internal substitutions in PNA chemistry.
Kersebohm
Tim
T
Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany.
Kirin
Srecko I
SI
Metzler-Nolte
Nils
N
D004247:DNA / Q000737:chemistry; D004151:Dipeptides / Q000737:chemistry*; D015394:Molecular Structure; D009691:Nucleic Acid Denaturation; D020135:Peptide Nucleic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D044366:Transition Temperature
D004151:Dipeptides; D020135:Peptide Nucleic Acids; D004247:DNA