Binding of phosphorothioate oligodeoxynucleotides to basic fibroblast growth factor, recombinant soluble CD4, laminin and fibronectin is P-chirality independent.
Antisense oligodeoxynucleotides can selectively inhibit the expression of individual genes and thus have potential applications in anticancer and antiviral therapy. A critical prerequisite to their use as therapeutic agents is the understanding of their non-specific interactions with biological structures, e.g. proteins. In this study we examined the interactions of P-chiral phosphorothioate oligodeoxynucleotides with several proteins. The Rp- and Sp- diastereomers, and racemic machine-made mixtures, or M-oligodeoxynucleotides were used independently as competitors of the binding of a probe, phosphodiester oligodeoxynucleotide bearing a 5' alkylating moiety, to rsCD4, bFGF and laminin. These oligodeoxynucleotides were also used as competitors of the binding of a non-alkylating probe M-phosphorothioate oligodeoxynucleotide, 5'-32P-SdT18 to fibronectin. The average values of and quantitative estimates for the IC50 of competition and the constant of competition (Kc) of Rp-, Sp- and M-stereoisomers of several homo- and heteropolymer oligodeoxynucleotides were determined and compared. Surprisingly, in the proteins we studied, the values of IC50 and Kc for the Rp-, Sp- and M-oligodeoxynucleotides were essentially identical. Thus, the ability of the phosphorothioate oligodeoxynucleotides we employed, to bind to the proteins studied in this work, is virtually independent of P-chirality. Our results also imply that the role of the purine and pyrimidine bases in oligodeoxynucleotide-protein interactions, as well as the nature of the contact points (sulfur versus oxygen) between the oligomer and the protein, may be relatively unimportant.
Benimetskaya
L
L
Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA.
Tonkinson
J L
JL
Koziolkiewicz
M
M
Karwowski
B
B
Guga
P
P
Zeltser
R
R
Stec
W
W
Stein
C A
CA
D001483:Base Sequence; D001667:Binding, Competitive; D015704:CD4 Antigens / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D007536:Isomerism; D007797:Laminin / Q000378:metabolism; D015335:Molecular Probes; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013873:Thionucleotides / Q000737:chemistry / Q000378:metabolism*
D015704:CD4 Antigens; D005353:Fibronectins; D007797:Laminin; D015335:Molecular Probes; D009838:Oligodeoxyribonucleotides; D011506:Proteins; D013873:Thionucleotides; D016222:Fibroblast Growth Factor 2