TY - JOUR
T1 - Preferential adsorption of a 'kinked' DNA to a neutral curved surface
T2 - Comparisons to and implications for nonspecific DNA-protein interactions
AU - Mahtab, Rahina
AU - Rogers, Jessica P.
AU - Singleton, Chainey P.
AU - Murphy, Catherine J.
PY - 1996/7/31
Y1 - 1996/7/31
N2 - We have examined the adsorption of different DNA sequences to mercaptoethanol-capped CdS quantum dots, ~40 Å diameter, as a minimalist model for nonspecific protein-DNA interactions, and compared these results to what we have previously found for Cd2+-surface-rich dots of the same size (Mahtab, R.; Rogers, J.P.; Murphy, C.J. J. Am. Chem. Soc. 1995, 117, 9099). We find that neutralization of the surface leads to no detectable binding, based on our luminescence assay, for 'straight' and A-tract oligonucleotides, while a crystallographically 'kinked' sequence does still bind, but by a factor of 4 less than that observed for a divalent metal ion-rich surface. The binding constants for both surfaces are within the range of nonspecific protein-DNA interactions. The kinetics of binding are also monitored and are compared to nonspecific protein-DNA interactions for large DNA fragments. Issues of biopolymer static bending vs flexibility are also addressed with fluorescence resonance energy transfer experiments.
AB - We have examined the adsorption of different DNA sequences to mercaptoethanol-capped CdS quantum dots, ~40 Å diameter, as a minimalist model for nonspecific protein-DNA interactions, and compared these results to what we have previously found for Cd2+-surface-rich dots of the same size (Mahtab, R.; Rogers, J.P.; Murphy, C.J. J. Am. Chem. Soc. 1995, 117, 9099). We find that neutralization of the surface leads to no detectable binding, based on our luminescence assay, for 'straight' and A-tract oligonucleotides, while a crystallographically 'kinked' sequence does still bind, but by a factor of 4 less than that observed for a divalent metal ion-rich surface. The binding constants for both surfaces are within the range of nonspecific protein-DNA interactions. The kinetics of binding are also monitored and are compared to nonspecific protein-DNA interactions for large DNA fragments. Issues of biopolymer static bending vs flexibility are also addressed with fluorescence resonance energy transfer experiments.
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U2 - 10.1021/ja961602e
DO - 10.1021/ja961602e
M3 - Article
AN - SCOPUS:0029785480
SN - 0002-7863
VL - 118
SP - 7028
EP - 7032
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 30
ER -