Rolf H. Berg

Peptide nucleic acids and their potential applications in biotechnology

Peptide nucleic acids (PNAs) are novel DNA mimics in which the sugar-phosphate backbone has been replaced with a backbone based on amino acids. PNAs exhibit sequence-specific binding to DNA and RNA with higher affinities and specificities than unmodified DNA. They are resistant to nuclease and protease attack in serum and cellular extracts and, thus, appear very promising as diagnostic and biomolecular probes, and possibly as antisense and antigene drugs.

Modification of the binding affinity of peptide nucleic acids (PNA). PNA with extended backbones consisting of 2-aminoethyl-β-alanine or 3-aminopropylglycine units

The binding affinity between peptide nucleic acids (PNA) and DNA is reduced by incorporation of PNA units with extended backbones.

Peptide nucleic acids containing adenine or guanine recognize thymine and cytosine in complementary DNA sequences

Peptide nucleic acid (PNA) monomer building blocks for the introduction of G and A are prepared and used to synthesise H-T4XT5-Lys-NH2(X = G or A), which are shown by Tm measurements to recognize their complementary DNA sequences in both the parallel (N-terminal PNA/5′-DNA) and the anti-parallel mode; the stoichiometry in each case is (PNA)2/DNA.

The synthesis, co-oligomerization and hybridization of a thymine-thymine heterodimer containing PNA

Abstract A peptide nucleic acid (PNA) decamer in which one of the amide bonds between two units is reversed was prepared and its binding affinity to complementary DNA is shown to be preserved.

Accelerated optical holographic recording using bis-DNO

Abstract The design, synthesis and optical holographic recording properties of bis-DNO are reported. Bis-DNO is composed of two identical azobenzene oligoornithine segments (DNO) connected via a dipeptide linker. The two segments were assembled in a parallel fashion at the two amino groups of the dipeptide linker by Merrifield synthesis. Surprisingly, the response time of films of bis-DNOs was found to be much faster than that of their linear counterparts.

Cycloaddition in Peptides for High-Capacity Optical Storage

Photodimerization of chromophores attached to a short peptide chain is investigated for high-capacity optical digital storage with UV lasers. The length and rigidity of the peptide chain assure an optimal distance and orientation of the chromophores for effective photodimerization. Using a theory developed by Tomlinson, the absorption cross section for the dimerization process in a uracil–ornithine-based hexamer is determined to be 9×10-20 cm2. A large change in the transmission due to irradiation in the UV area may make it possible to realize multilevel storage in a thin film of the peptides.

Structural properties of DNO investigated with pyrene excimer formation.

Four diamino acid‐Nα‐substituted oligopeptide (DNO) oligomers substituted with pyrenyl as photophysical probes were synthesized. The excimer formation and ground‐state association of the pyrenyl groups were investigated by means of absorption and steady‐state fluorescence spectroscopy together with time‐resolved fluorescence techniques. The photophysical parameters obtained from the different derivatives reflect the secondary structural properties of the DNO backbones. Copyright