01487nas a2200157   4500008004100000022001400041245016200055210006900217260007100286300001400357490000700371520077900378100001701157700002401174856013101198       2012                        eng d  a0022-326300aAminomethylene peptide nucleic acid (am-PNA): synthesis, regio-/stereospecific DNA binding, and differential cell uptake of (alpha/gamma,R/S)am-PNA analogues0 aAminomethylene peptide nucleic acid amPNA synthesis regiostereos  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL  a5696-57040 v773 a<p>Inherently chiral, cationic am-PNAs having pendant aminomethylene groups at alpha(R/S) or gamma(S) sites on PNA backbone have been synthesized. The modified PNAs are shown to stabilize duplexes with complementary cDNA in a regio- and stereo-preferred manner with gamma(S)-am PNA superior to alpha(R/S)-am PNAs and alpha(R)-am PNA better than the alpha(S) isomer. The enhanced stabilization of am-PNA:DNA duplexes is accompanied by a greater discrimination of mismatched bases. This seems to be a combined result of both electrostatic interactions and conformational preorganization of backbone favoring the cDNA binding. The am-PNAs are demonstrated to effectively traverse the cell membrane, localize in the nucleus of He La cells, and exhibit low toxicity to cells.</p>1 aMitra, Roopa1 aGanesh, Krishna, N.  uhttps://library.ncl.res.in/content/aminomethylene-peptide-nucleic-acid-am-pna-synthesis-regio-stereospecific-dna-binding-and-0