Immobilized enzyme-based analytical tools in the -omics era: recent advances

Protein analysis is a field under rapid development mainly thanks to technological advances which have granted miniaturization of analytical devices, automation and higher detection sensitivity. The interest in the field has paralleled the expansion of the -omics era, laying down the bases for the current applications in proteomics and glycomics. Advances in protein sample transformation prior to analysis have led to reduction of sample consumption and contamination, enhancing throughput. Within this context, and thanks to the availability of new high performing materials and technologies, increasingly more efficient and miniaturized enzyme-based analytical tools have been proposed to overcome shortcomings encountered in the in-solution enzymatic reactions (protein digestion and protein deglycosylation, for proteomics and glycomics, respectively). In this context, immobilized enzyme reactors (IMERs) and IMER-based platforms have been developed as promising approaches toward automation and higher analysis throughput. The scenario is in continuous development as underlined by thirty-four papers published in the last five years. This review encompasses recent advances in the design and operational set-ups of IMERs purposely developed for the analysis of proteins and glycoproteins. Recently developed dual IMERs, which integrate more than one processing step into a single IMER, and analytical platforms exploiting tandem IMERs are also reviewed and commented.