Enantioselective DNA condensation induced by heptameric lanthanum helical supramolecular enantiomers

DNA condensation induced by a pair of heptameric La(III) helical enantiomers M-[La-7(S-L)(6)(CO3)(NO3)(6)(OCH3) (CH3OH)(7)]center dot 2CH(3)OH center dot 5H(2)O and P-[La-7(R-L)(6)(CO3)(NO3)(6)(OCH3)(CH3OH)(5)(H2O)(2)]center dot 2CH(3)OH center dot 4H(2)O (M-La and P-La, L = 2-(2-hydroxybenzylamino)-3-carbamoylpropanoic acid) has been investigated by UV/vis spectroscopy, fluorescence spectroscopy, CD spectroscopy, EMSA, RALS, DLS, and SEM. The enantiomers M-La and P-La could induce CT-DNA condensation at a low concentration as observed in UV/vis spectroscopy. DNA condensates possessed globular nanopartides with nearly homogeneous sizes in solid state determined by SEM (ca. 250 nm for M-La and ca. 200 nm for P-La). The enantiomers bound to DNA through electrostatic attraction and hydrogen bond interactions in a major groove, and rapidly condensed free DNA into its compact state. DNA decompaction has been acquired by using EDTA as disassembly agent, and analyzed by UV/vis spectroscopy, CD spectroscopy and EMSA. Moreover, the enantiomers M-La and P-La displayed discernible discrimination in DNA interaction and DNA condensation, as well as DNA decondensation. Our study suggested that lanthanum(III) enantiomers M-La and P-La were efficient DNA packaging agents with potential applications in gene delivery. (C) 2014 Elsevier Inc. All rights reserved.