Efficient bacterial expression of fusion proteins and their selective processing by a recombinant Kex-1 protease.

A secreted, soluble variant of the Kex-1 endopeptidase from Kluyveromyces lactis has been produced and studied as a novel cleavage enzyme exhibiting high specificity for the Lys-Arg peptide. This highly selective, efficient enzyme is particularly adapted for use in manufacturing when a recombinant therapeutic protein, possessing its native N-terminus, has to be released in vitro from a bacterially-expressed fusion protein. In this paper, we describe the preparation of a Kex-1 variant using Saccharomyces cerevisiae and its application in the production of important therapeutic recombinant proteins such as human growth hormone, granulocyte colony-stimulating factor and interferon-alpha-2b.

Temperature-dependent, irreversible formation of amyloid fibrils by a soluble human ataxin-3 carrying a moderately expanded polyglutamine stretch (Q36).

The protein ataxin-3 is responsible for Machado-Joseph disease/spinocerebellar ataxia type 3, a neurodegenerative disorder caused by the presence of an expanded polyglutamine tract. A previous investigation [Bevivino, A. E.