Purification, characterization and preparation immunomatrixes of S-layer proteins ofThermobifida fusca

Abstract

S-layer proteins are considered as a good nanocarrier due to their binding and self-assembled properties. These can be used to prepare the immunomatrixes for the removal of toxins from the samples. Two S-layer proteins 70 and 40kDa of thermophilic Thermobifida fusca were extracted with guanidine hydrochloride and purified. Antibodies against S-layer proteins were developed, and their monospecificity was checked. Immunogold labelling indicated that these are surface proteins. Immunomatrixes (70-SLIM, 40 SLIM) were prepared by covalently immobilizing S-layer proteins in microwell and further conjugated with anti- Staphylococcus aureus enterotoxin B (SEB) antibodies. The binding of 70 and 40kDa proteins was observed nearly 7·0μgcm(-1) to binding area, and the conjugation with anti-SEB antibodies was found 1·22μgμg(-1) of 70kDa and 0·875μgμg(-1) of 40kDa. The average binding and elution of pure SEB toxin on 70-SLIM and 40-SLIM was 5·0μg SEB toxin. The SEB toxin in milk samples was also removed on immunomatrixes successfully. It is the first report, and this study shows that the thermophilic S-layer proteins can be used to prepare the immunomatrixes. Information in this study can be used to design the strategies for the removal of biologically important materials or toxins from samples.