ena-STUDY-University of Lincoln-06-03-2018-13:10:51:046-3375
Modular assembly of proteins on nanoparticles
Decoration of nanoparticles with biomolecules has applications in drug delivery and medical diagnostics and can be achieved using a range of well-established chemistries. However, when it comes to structurally complex molecules such as proteins, their intrinsic diversity makes it difficult to find a universal chemical cross-linking strategy that consistently produce functional nanoparticles conjugates. Therefore, protocols for immobilisation have to be empirically and tediously optimised case-by-case.   On the other hand, proteins can adsorb spontaneously onto metal surfaces as it is the case for antibodies adsorbed onto gold nanoparticles for their use in lateral flow assays or immunogold staining of tissues. Although passive adsorption is straightforward, unfortunately the adsorbed protein is likely to undergo denaturation, it is not uniformly oriented and, overall, its functionality is compromised.Here we study the use of intermediate designer proteins that are adsorbed onto gold nanoparticles, they contribute to the stability of the colloid suspension and carry a domain which specifically binds to an affinity tag. An arbitrary protein of interest which presents a specific counter-tag can bind to the functionalised particles by simple mixing, with reduced chance to undergo denaturation and inactivation. Importantly, by using this hierarchical strategy, there is no need for optimisation of the conditions, as these are only determined by the affinity system and not by a nanoparticle-protein interaction.
Decoration of nanoparticles with biomolecules has applications in drug delivery and medical diagnostics and can be achieved using a range of well-established chemistries. However, when it comes to structurally complex molecules such as proteins, their intrinsic diversity makes it difficult to find a universal chemical cross-linking strategy that consistently produce functional nanoparticles conjugates. Therefore, protocols for immobilisation have to be empirically and tediously optimised case-by-case.   On the other hand, proteins can adsorb spontaneously onto metal surfaces as it is the case for antibodies adsorbed onto gold nanoparticles for their use in lateral flow assays or immunogold staining of tissues. Although passive adsorption is straightforward, unfortunately the adsorbed protein is likely to undergo denaturation, it is not uniformly oriented and, overall, its functionality is compromised.Here we study the use of intermediate designer proteins that are adsorbed onto gold nanoparticles, they contribute to the stability of the colloid suspension and carry a domain which specifically binds to an affinity tag. An arbitrary protein of interest which presents a specific counter-tag can bind to the functionalised particles by simple mixing, with reduced chance to undergo denaturation and inactivation. Importantly, by using this hierarchical strategy, there is no need for optimisation of the conditions, as these are only determined by the affinity system and not by a nanoparticle-protein interaction.