Isolation and characterization of a cell-associated protein of Bacillus pumilus PH-01

A cell-associated protein released from Bacillus pumilus PH-01 showed an af finity for some dioxins, like 1,2,3,4-tetrachlorodibenzo-p-dioxin (TCDD) an d 1,2,3,4-tetrachlorodibenzofuran (TCDF), and the concentration of the prot ein increased when B. pumilus PH-01 was boiled in minimal salts medium. Sod ium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization-mass spectrometry revealed that the boiled cult ure supernatant contained a major protein with a molecular mass of 5,313.4 Da. The adsorption behavior of the protein for 1,2,3,4-TCDD and 1,2,3,4-TCD F was examined by digesting it with proteinase K and trypsin, showing that the proteolyzed protein lost the ability to adsorb the compounds. The amino acid sequence of the protein was determined by automated Edman degradation and tandem mass spectrometry. A search of the protein databases showed no existence of proteins with an homologous sequence.