Thermodynamic Analysis of Proteins Adsorbed on Silica Particles: Electrostatic Effects
Abstract
Electrostatic effects on protein adsorption were investigated using differential scanning calorimetry (DSC) and adsorption isotherms. The thermal denaturation of lysozyme, ribonuclease A (RNase), and alpha-lactalbumin in solution and adsorbed onto silica nanoparticles was examined at three concentrations of cations: 10 and 100 mM of sodium and 100 mM of sodium to which 10 mM of calcium was added. The parameters investigated were the denaturation enthalpy (DeltaH), the temperature at which the denaturation transition was half-completed (T(m)), and the temperature range of the denaturation transition. For lysozyme and RNase, adsorption isotherms depend strongly on the ionic strength. At low ionic strength both proteins have a high affinity for the silica particles and adsorption is accompanied by a 15-25% reduction in DeltaH and a 3-6 degrees C decrease in T(m), indicating that the adsorbed state of the proteins is destabilized. Also, an increase in the width of the denaturation transition is observed, signifying a larger conformational heterogeneity of the surface bound proteins. At higher ionic strengths, both with and without the addition of calcium, no significant adsorption-induced alteration in DeltaH was observed for all t...Continue Reading
References
Citations
Characterization of protein adsorption onto silica nanoparticles: influence of pH and ionic strength
Kinetic and structural characterization of adsorption-induced unfolding of bovine alpha -lactalbumin
Related Feeds
Bacterial Cell Wall Structure (ASM)
Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Here is the latest research on bacterial cell wall structures.
Bacterial Cell Wall Structure
Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Here is the latest research on bacterial cell wall structures.