Recognition and strand displacement of DNA oligonucleotides by peptide nucleic acids (PNAs). High-performance ion-exchange chromatographic analysis.
Peptide nucleic acids (PNAs) are oligonucleotide mimics containing a pseudopeptide chain, which are able to bind complementary DNA tracts with high affinity and selectivity. Two mixed-sequence PNA undecamers (1 and 2) were synthesized and their double-stranded adducts with the complementary oligonucleotides (3 and 4) were revealed by the appearance of the corresponding peak in anion-exchange HPLC. A DEAE column was used and elution was performed with aqueous Tris buffer (pH 8) and an ionic strength gradient (0-0.5 M NaCl). The same effect was not observed with non-complementary oligonucleotides. The stability of the PNA-DNA adducts under the conditions used in the chromatographic system was studied as a function of temperature. Furthermore, in competition experiments double-stranded oligonucleotides were challenged by a PNA complementary to one strand: the formation of the PNA-DNA hybrid and the displacement of the non-complementary strand were observed with high specificity. The results suggest a possible use of ion-exchange HPLC for studying PNA-DNA interactions, and indicate the efficiency of PNA probes in the chromatographic analysis of DNA.
Lesignoli
E
E
Dipartimento di Chimica Organica e Industriale, Università di Parma, Italy.
Germini
A
A
Corradini
R
R
Sforza
S
S
Galavema
G
G
Dossena
A
A
Marchelli
R
R
D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D013696:Temperature
D020135:Peptide Nucleic Acids; D004247:DNA