TY - JOUR
T1 - The Mechanistic and Structural Features of Protein Adsorption onto Mesoporous Silicates
AU - Hodnett, Kieran
AU - Deere, Joseph
AU - Magner, Edmond
AU - Wall, J. Gerard
PY - 2002/7/25
Y1 - 2002/7/25
N2 - The adsorption of cytochrome c onto a range of different mesoporous silicates (MPS) was studied. The materials used, templated using both cationic and nonionic surfactants, have average pore-size diameters in the range from 28 to 130 Å. Cytochrome c was found to bind to all MPS investigated, with the pore diameter of the material, which was measured by N2 gas adsorption, being crucial to mesopore penetration. The adsorption of a range of proteins with isoelectric points between 1 and 10 was investigated. For adsorption to occur, the surface charges of the protein and of the MPS must be complementary, in addition to the requirement that the pore diameter be sufficiently large. Pepsin at pH 6.5, for example, is negatively charged and does not adsorb onto cyano-modified silicate whereas subtilisin, which is of a similar size and bears an overall positive charge, is adsorbed. Using resonance Raman spectroscopy, cytochrome c was observed to occur in both high spin and low spin states, in contrast to that in solution, where the protein is predominantly in the low spin state. The presence of the high spin state may account for the enhanced peroxidative activity of the adsorbed protein.
AB - The adsorption of cytochrome c onto a range of different mesoporous silicates (MPS) was studied. The materials used, templated using both cationic and nonionic surfactants, have average pore-size diameters in the range from 28 to 130 Å. Cytochrome c was found to bind to all MPS investigated, with the pore diameter of the material, which was measured by N2 gas adsorption, being crucial to mesopore penetration. The adsorption of a range of proteins with isoelectric points between 1 and 10 was investigated. For adsorption to occur, the surface charges of the protein and of the MPS must be complementary, in addition to the requirement that the pore diameter be sufficiently large. Pepsin at pH 6.5, for example, is negatively charged and does not adsorb onto cyano-modified silicate whereas subtilisin, which is of a similar size and bears an overall positive charge, is adsorbed. Using resonance Raman spectroscopy, cytochrome c was observed to occur in both high spin and low spin states, in contrast to that in solution, where the protein is predominantly in the low spin state. The presence of the high spin state may account for the enhanced peroxidative activity of the adsorbed protein.
UR - http://www.scopus.com/inward/record.url?scp=0037173849&partnerID=8YFLogxK
U2 - 10.1021/jp0139484
DO - 10.1021/jp0139484
M3 - Article
AN - SCOPUS:0037173849
SN - 1520-6106
VL - 106
SP - 7340
EP - 7347
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 29
ER -