Our interests are in the design and characterization of immobilized fusion proteins . In particular, we are interested in creating immobilized kinases due to their widespread utility in biochemical applications and their potential applications in bioreactor chemistry . Although several kinases have been studied in their immobilized form , general solutions to kinase immobilization remain elusive. For this work, we selected the catalytic subunit of cAMP-dependent Protein Kinase A (PKAcs), a 'central kinase' in cell signaling, for incorporation into an immobilized protein fusion. PKA, a member of the superfamily of eukaryotic protein kinases, is composed of a regulatory (R) and a catalytic (C) subunit. Following cAMP binding to the holoenzyme, the C subunit is released in active form to phosphorylate a plethora of substrates . PKA is a critical kinase contributing to many cell signaling pathways, associating with a multitude of vital cellular processes such as cell survival, muscle contraction, and nerve impulses . Consequently, a functional immobilized PKA catalytic subunit would have numerous applications in biotechnology, proteomics, and cell biology .