Enzyme/DNA/alpha-ZrP Nanocomposites: DNA assisted enhancement of enzymatic activity

Keywords:
DNA, hemoglobin, circular dichroism, activity, co-intercalation

Abstract:
The first example of protein assisted DNA binding and DNA assisted protein activity enhancement at a layered, inorganic solid is reported here. Met-hemoglobin (Hb), for example, facilitated the co-intercalation of calf thymus DNA in the galleries of alpha-Zr(IV) phosphate (alpha-Zr(HPO4)2.H2O, abbreviated as alpha-ZrP), and DNA did not bind to the solid in the absence of Hb. Exposure of a suspension of a-ZrP to a solution of Hb (100 µM, 6.45 mg/ml, 10 mM K2HPO4, pH 7.2) and Calf-Thymus DNA (262 µM in base pairs) resulted in the incorporation of the protein, and DNA in the galleries. Co-intercalation of DNA improved the structure and activity of intercalated Hb and also that of met-myoglobin (Mb). The circular dichroism (CD) spectra of the bound protein, for example, is almost super imposable with that of the free protein in solution. The peroxidase-like activity of bound Hb was enhanced five-fold when DNA was co-immobilized, much closer to that of the free Hb in solution. Similar results are indicated with Mb, and these enhancements in the properties of the bound protein are not limited to Hb. The strong role of DNA in enhancing bound protein properties is novel, and this is the first report of protein-assisted DNA binding to negatively charged, layered material. Such materials provide new opportunities for the application of DNA-protein-inorganic materials.

Back to Program

Nanotech 2006 Conference Program Abstract