Site-specific conjugation of antifreeze proteins onto polymer-stabilized nanoparticles

Abstract

Antifreeze proteins are site-specifically conjugated onto polymer-stabilised gold nanoparticles, resulting in hybrid materials capable of modulating ice growth processes.

Ice recrystallisation inhibiting polymer nano-objects via saline-tolerant polymerisation-induced self-assembly

“…Immobilisation of PVA onto gold particles by ‘grafting to’ retains, but does not enhance, activity 24 as do coacervates. 25 Similarly, assembly of Type III AFPs into dendrimers 26 or on gold particles 27 allows binding of multiple ice faces, but affords no overall increase in activity. This is surprising as AFP/IBPs typically show more activity as molecular weight or aggregation increases 28 , 29 and theory predicts that the rate of ice nucleation requires large protein aggregates to function.…”

Extracellular Antifreeze Protein Significantly Enhances the Cryopreservation of Cell Monolayers

“…Recombinant AFPIII was expressed in Escherichia coli ( E. coli ) and purified according to previously published methods (Supporting Information). 51 Site-directed mutagenesis of the terminal Ala present within the AFPIII encoding plasmid was used to produce a mutant cysteine variant of AFPIII (AFP-Cys), enabling site-specific conjugation to Alexa Fluor 488 Maleimide (AFPIII-Alexa Fluor 488) for fluorescence-based quantification and imaging (Supporting Information).…”

X-ray diffraction to probe the kinetics of ice recrystallization inhibition

“…Gold nanoparticles were synthesised as reported previously. 48 For washing of AuNPs, Amicon Ultra-0.5 centrifugal filter units with Ultracel-30 membrane were used. 40 nm citrate-stabilised gold colloid solution was purchased from BBI solutions.…”