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Investigation of the Interactions of β ‐Peptides with DNA Duplexes by Circular Dichroism Spectroscopy
Author(s) -
Namoto Kenji,
Gardiner James,
Kimmerlin Thierry,
Seebach Dieter
Publication year - 2006
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200690277
Subject(s) - chemistry , circular dichroism , dna , peptide , side chain , stereochemistry , helix (gastropod) , sequence (biology) , duplex (building) , base pair , crystallography , biophysics , biochemistry , polymer , ecology , organic chemistry , snail , biology
The interaction of β ‐peptides with the DNA duplexes of dA 20 dT 20 and a GCN4‐binding CRE sequence was examined. To gauge the factors that govern these interactions, two β ‐pentadecapeptides, 1 and 2 , a β ‐dodecapeptide, 3 , three β ‐decapeptides, 4 – 6 , three β ‐heptapeptides, 7 – 9 , and β ‐octaarginine 10 were designed and synthesized. The β ‐peptides were conceived to adopt a β ‐peptide 3 14 helix, in which the side chains at position i and i + 3 are aligned vertically along one side of the helix. The side chains of Lys, Asn, and Arg were positioned such that potential H‐bonding sites were created for a helical conformation to interact with the base pairs of DNA. CD Analysis showed that β ‐peptides 1, 2 , and 10 interacted with dA 20 dT 20 . In addition, β ‐peptides 1 and 2 showed significant interaction with a DNA‐duplex 20mer containing the ATF/CREB recognition sequence for the regulatory protein GCN4. It is impossible, at this stage of the investigation, to make a safe proposal about the actual nature of the interaction of the structures(s) of the complexes, the formation of which is suggested by the CD spectra reported herein.