HIGH-LEVEL EXPRESSION OF FUNCTIONAL CGMP-DEPENDENT PROTEIN-KINASE USING THE BACULOVIRUS SYSTEM

The understanding of the structure and function of cGMP-dependent prot ein kinase (cGMP kinase) has been hindered by the difficulty to obtain large quantities of functional enzyme. A recombinant baculovirus enco ding bovine cGMP kinase I alpha was constructed and purified. Infected insect cells synthesized large amounts of soluble and biologically ac tive cGMP kinase I alpha representing up to 10% of the total cell extr act protein. The recombinant enzyme had an identical apparent molecula r mass, cGMP affinity and kinase activity as the native bovine lung en zyme. The high-level expression of functional cGMP kinase I alpha shou ld provide an excellent tool to study further the structure and functi on of cGMP kinase.