01058nas a2200157   4500008004100000022001400041245014000055210006900195260011000264300001400374490000700388520033400395100001700729700002400746856013000770       2011                        eng d  a1359-734500aPNAs grafted with (alpha/gamma, R/S)-aminomethylene pendants: Regio and stereo specific effects on DNA binding and improved cell uptake0 aPNAs grafted with alphagamma RSaminomethylene pendants Regio and  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a1198-12000 v473 a<p>PNAs grafted with cationic aminomethylene (am) pendants on the backbone at the glycyl (alpha) or ethylenediamine (gamma) segments show regio (alpha/gamma) and stereochemistry (R/S) dependent binding with complementary DNA. These are efficiently taken up by cells, with gamma(S-am) aeg-PNA being the best in all properties.</p>1 aMitra, Roopa1 aGanesh, Krishna, N.  uhttps://library.ncl.res.in/content/pnas-grafted-alphagamma-rs-aminomethylene-pendants-regio-and-stereo-specific-effects-dna-001487nas 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