1.Recognition by nonaromatic and stereochemical subunit-containing polyamides of the four Watson-Crick base pairs in the DNA minor groove.
Zhang HF1, Wu YL, Jiang SK, Wang P, Sugiyama H, Chen XL, Zhang W, Ji YJ, Guo CX. Chembiochem. 2012 Jun 18;13(9):1366-74. doi: 10.1002/cbic.201200137. Epub 2012 May 21.
In order to develop an optimal subunit as a T-recognition element in hairpin polyamides, 15 novel chirality-modified polyamides containing (R)-α,β-diaminopropionic acid ((R) β α-NH 2), (S)-α,β-diaminopropionic acid ((S) β α-NH 2), (1R,3S)-3-aminocyclopentanecarboxylic acid ((RS) Cp), (1S,3R)-3-amino-cyclopentanecarboxylic acid ((RS) Cp), (1R,3R)-3-aminocyclopentanecarboxylic acid ((RR) Cp) and (1S,3S)-3-amino-cyclopentanecarboxylic acid ((SS) Cp) residues were synthesized. Their binding characteristics to DNA sequences 5'-TGCNCAT-3'/3'-ACGN'GTA-5' (N⋅N'=A⋅T, T⋅A, G⋅C and C⋅G) were systemically studied by surface plasmon resonance (SPR) and molecular simulation (MSim) techniques. SPR showed that polyamide 4, AcIm-(S) β α-NH 2-ImPy-γ-ImPy-β-Py-βDp (β/(S) β α-NH 2 pair), bound to a DNA sequence containing a core binding site of 5'-TGCACAT-3' with a dissociation equilibrium constant (K(D) ) of 4.5×10(-8) m. This was a tenfold improvement in specificity over 5'-TGCTCAT-3' (K(D) =4.