Polydopamine Grafted Porous Graphene as Biocompatible Nanoreactor for Efficient Identification of Membrane Proteins

Functional nanomaterials,
used as nanoreactors, have shown great advantages in a variety of
applications in biomedical fields. Herein, we designed a novel nanoreactor
system toward the application in membrane proteomics by using polydopamine-coated
nanoporous graphene foams (NGFs-PD) prepared by a facile in
situ oxidative polymerization. Taking advantage of the unique
3-D structure and surface functionalization, NGFs-PD can quickly adsorb
a large amount of hydrophobic membrane proteins dissolved in sodium
dodecyl sulfonate (SDS)/methanol and hydrophilic trypsin in aqueous
solution, and then confine the proteolysis in the nanoscale domains
to fasten the reaction rate. Therefore, the current nanoreactor system
combines the multifunctions of highly efficient solubilization, immobilization,
and proteolysis of membrane proteins. With the nanoreactor, digestion
of standard membrane proteins can be finished in 10 min. 893 membrane
proteins were identified from human glioma cells (U251). All these
superiorities indicate that the biocompatible NGFs-PD nanoreactor
system is of great promise to facilitate high-throughput membrane
proteomic analysis.