Purification and characterisation of BstLVI restriction endonuclease, a thermostable isoschizomer of ClaI from Bacillus stearothermophilus LV

Abstract

This work describes the purification and biochemical characterization of BstLVI restriction endonuclease, a thermostable isoschizomer of ClaI, from Bacillus stearothermophilus LV. The enzyme was purified by successive DEAE-cellulose, Affi-Gel Blue and Heparin-Sepharose CL-6B column chromatography. A molecular weight of 37 000 was determined for BstLVI by gel filtration. As expected from thermophilic proteins, the enzyme showed a high stability towards heat and also to other known protein-denaturing agents.