Development of Novel Biological Nanomaterials through Protein Chemical Modification

Enzymes are capable of catalyzing many different reactions, some of which are not possible through conventional organic chemistry methods. However, their sensitive nature to environmental conditions such as pH, temperature, solvents, and denaturants limits their applications. One method of stabilizing protein against denaturing conditions is to adsorb them onto the surface of nanomaterials such as 3D nanoparticles, 2D inorganic nanodisks or even creating carrier free protein nanoparticles with no support system present. However, even these methods have drawbacks of low enzyme loadings, loss in activity and cost of production. The object of this dissertation was to develop novel nanomaterials. First, to better understand the physical properties that effect protein adsorbing to nanoparticles, enzymes were modified chemically to alter net protein charge so that the relationship of charge on the enzyme to charge on ⍺-ZrP could be better understood. It was concluded that protein charge and ions present in solution play an important governing role in how much enzyme can be adsorbed onto a surface. Development of facile surface modification method for controlling the physical properties of nanoparticles for enhanced enzyme adsorption. Protein was modified chemically to have a net positive charge, resulting in favorable binding between the positively charge protein and negatively charge silica nanoparticle surface. Anionic catalytic enzymes were adsorbed onto this nanomaterial and their percent loading and catalytic activity assessed. For both enzymes investigated, percent loading (m/m) and catalytic activity retention were among the highest reported to date. Lastly a nanoparticle made of protein with independently tunable emission, size and surface properties was synthesized. These particles are biodegradable, nontoxic and capable of white emission. White emitting particles are highly sensitive to cellular local environment. The methods of investigation and interpretation of the results are discussed in full in this work.