la047994h_si_001.pdf (45.99 kB)
Structure and Function of Enzymes Adsorbed onto Single-Walled Carbon Nanotubes
journal contribution
posted on 2004-12-21, 00:00 authored by Sandeep S. Karajanagi, Alexey A. Vertegel, Ravi S. Kane, Jonathan S. DordickWe have examined the structure and function of two enzymes, α-chymotrypsin (CT) and soybean peroxidase
(SBP), adsorbed onto single-walled carbon nanotubes (SWNTs). SBP retained up to 30% of its native
activity upon adsorption, while the adsorbed CT retained only 1% of its native activity. Analysis of the
secondary structure of the proteins via FT-IR spectroscopy revealed that both enzymes undergo structural
changes upon adsorption, with substantial secondary structural perturbation observed for CT. Consistent
with these results, AFM images of the adsorbed enzymes indicated that SBP retains its native three-dimensional shape while CT appears to unfold on the SWNT surface. This study represents the first in
depth investigation of protein structure and function on carbon nanotubes, which is critical in designing
optimal carbon nanotube−protein conjugates.