DNA, cell cultures and methods for the secretion of heterologous proteins and periplasmic protein recovery.

摘要

Direct linkage of DNA encoding prokaryotic signals such as E. coli enterotoxin with DNA encoding mature eukaryotic proteins, followed by transformation and culture of bacterial hosts characterized by a periplasmic space, yields substantial amounts of periplasmic mature protein. Constitutively promoted gram negative bacterial mutants are transformed with vectors containing DNA encoding a secretable heterologous protein under the transcriptional control of a constitutively promoted promoter. Periplasmic proteins are recovered from transformed gram negative bacteria by a process comprising freezing and thawing the cells. Advantages are obtained by culturing the cells in phosphate-limiting media and by killing the cells prior to separation of periplasmic proteins.