Holger Wallmeier

The Tendamistat Expression-Secretion System: Synthesis of Proinsulin Fusion Proteins with Streptomyces Lividans

Tendamistat (HOE 467), a potent inhibitor of the human pancreatic α-amylase, is an acidic protein of 74 amino acids (Vertesy et al., 1984). The inhibitor gene was cloned from an amplified genomic sequence of an over-producing strain of Streptomyces tendae and further characterized. By expression of the gene in the heterologous host Streptomyces lividans we demonstrated that secretion of this protein was mediated by a signal peptide dependent mechanism (Koller & Ries, 1989). We have also evaluated the tendamistat-based secretion system for a number of foreign proteins, for example interleukin II and proinsulin (Bender et al., 1990, Koller et al., 1989). Our main interest focussed on the formation of disulphide bonds, stability and activity of secreted proteins.