Chiral recognition of deoxyoligonucleotides by delta- and lambda-tris(ethylenediamine)cobalt(III).
59Co NMR and CD measurements show for both stereoisomers of Co(en)3(3+) a similar trend in the sequence dependence of DNA recognition, as was reported previously for Co(NH3)6(3+). In particular, specific binding is evident to DNA molecules possessing runs of two or more same-strand guanine residues. The binding of either isomer to such sequences induces structural transitions toward A-DNA characteristics. Such measurements also show significant differences between the two stereoisomers in terms of how they recognize specific duplex DNA sequences. delta-Co(en)3(3+) binds more tightly than lambda-Co(en)3(3+) to right-handed, guanine-rich DNA, whereas lambda-Co(en)3(3+) binds more tightly than delta-Co(en)3(3+) to left-handed DNA. The two stereoisomers bind in an indistinguishable manner to AT-rich DNA.
Xu
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Chemistry Department, University of Nebraska, Lincoln 68588-0304, USA.
Jampani
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SR
Deng
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H
Braunlin
W H
WH
D001483:Base Sequence; D002942:Circular Dichroism; D003035:Cobalt / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D012492:Salts; D012996:Solutions; D013237:Stereoisomerism
D005029:Ethylenediamines; D009838:Oligodeoxyribonucleotides; D009942:Organometallic Compounds; D012492:Salts; D012996:Solutions; C096699:tris(ethylenediamine)cobalt(III); D003035:Cobalt; D004247:DNA