Increased protein stability/activity upon
binding to nanoparticles
While, in general, the loss of secondary structure and consequent
changes in the activity of proteins upon binding to nanoparticles can be
seen as a drawback or a potential source of nanoparticle toxicity, there
is a potential positive outcome too. Promising uses of nanoparticles
include increasing protein stability toward enzyme degradation and
increasing the activity of enzymes via immobilization at surfaces.
Enzymes such as Candida rugosa lipase (CRL) and Pseudomonas
cepacia lipase (PCL) have been adsorbed to nanostructured polystyrene
(PS) and polymethylmethacrylate (PMMA) by simple addition of the
lipase solution to the polymeric nanoparticles under protein-friendly
conditions (pH 7.6)37. Adsorption leads to improved performance in
terms of activity and selectivity with respect to that shown by lipases
adsorbed on the same non-nanostructured carriers,as well as increased
enantioselectivity and pH and thermal stability37.