Overproduction of the bleomycin-binding proteins from bleomycin-producing Streptomyces verticillus and a methicillin-resistant Staphylococcus aureus in Escherichia coli and their immunological characterisation.

The bleomycin-binding proteins designated BLMA and BLMS, which confer resistance to bleomycin (Bm), from Bm-producing Streptomyces verticillus ATCC15003 and a methicillin-resistant Staphylococcus aureus B-26, respectively, were overexpressed in Escherichia coli. The present study showed that both BLMA and BLMS quench the antibacterial activity of Bm by the binding to the drug. To immuno-characterize the Bm-binding proteins, we constructed a monoclonal antibody against BLMA. The antibody, designated 893-12, did not cross react to BLMS and another Bm-binding protein from tallysomycin-producing Streptoalloteichus hindustanus. Although the ability of Bm to cleavage DNA was eliminated by a binding of BLMA to Bm, as shown by Sugiyama et al. [Gene 151 (1994) 11-15], the Bm-induced DNA degradation was restored by pre-incubation of BLMA with the anti-BLMA monoclonal antibody.