Functional expression on bacteriophage of the mustard trypsin inhibitor MTI-2

The mustard trypsin inhibitor MTI-2 is a potential tool in the study of int eractions between pest insects and plants. It can be applied to study the a daptations of digestive proteases in pest insects. Phage display allows a r apid and exhaustive system for the selection of heterologous protein varian ts with novel specificities. Here we describe a bacteriophage expression sy stem which permits functional expression of MTI-2 variants. Active and inac tive mutants of NITI-S are constructed and displayed on phage. These are us ed to demonstrate that an active variant can be selected from a background of 10,000 inactive mutants in four rounds of selection and amplification. ( C) 2001 Academic Press.