Affinity chromatography resins that are obtained by conjugation of matrices with proteins of bacterial origin, like protein A, are frequently used for the purification of numerous therapeutic monoclonal antibodies. This article presents the development of a biocatalytic method for the production of novel affinity resins with an immobilized mutant form of protein A via sortase A mediated reaction. The conditions for activation of the agarose Seplife 6FF matrix, selection of different types of linkers with free amino groups and conditions for immobilization of recombinant protein A on the surface of the activated matrix were studied. Finally, the basic operational properties, like dynamic binding capacity (DBC), temperature dependance of DBC and stability during the cleaning-in-place process of the affinity resin with the Gly-Gly-EDA-Gly-Gly linker, were assessed using recombinant hyperchimeric monoclonal antibodies. The main characteristics show comparable results with the widely used commercial samples.

A chimeric RNase A inhibitor (SUMO-RI) was produced by fusing a SUMO domain to the N-terminus of the murine Rnh1 protein. Functional assays demonstrated that SUMO-RI effectively protects RNA from RNase A-mediated degradation under conditions mimicking real-time RT-PCR, with performance comparable to that of commercial RNase inhibitors. The primary advantage of the chimeric design is its improved technological suitability: SUMO-RI exhibits markedly enhanced storage stability relative to the recombinant Rnh1 inhibitor. However, this benefit comes with a trade-off—SUMO fusion reduces thermostability at temperatures above approximately 47 °C. Together, these findings establish SUMO fusion as a rational engineering strategy for RNase inhibitors, offering improved practical handling at the expense of thermal resilience.