Production and Purification of the Extracellular Ribonuclease of Bacillus Amyloliquefaciens (Barnase) and its Intracellular Inhibitor (Barstar)

Abstract

Procedures are presented for the large-scale growth of Bacillus amylo-liquefaciens and the concentration and purification of its extracellular ribo-nuclease (barnase). Improvements over earlier methods include economy, the reduction of labor, and Improved purity of product, especially in the elimination of traces of protease. The bacterial cells obtained as a by-product may be used as a starting point for the isolation of barstar, the intracellular inhibitor of barnase¹. Experiments relating to the purity, amino-acid composition and molecular weight of the product are also reported.