PURIFICATION AND FUNCTIONAL-ANALYSIS OF THE DNAK HOMOLOG FROM PREVOTELLA-INTERMEDIA OMZ-326

This study examined heat shock proteins (hsps) of the periodontal path ogen Prevotella intermedia and the closely related species, Prevotella nigrescens and Prevotella corporis. After heat shock at 45 degrees C for 5 min, cell-free extracts were analysed by SDS-PAGE and Western bl otting with polyclonal antibodies against Escherichia coli hsps, P. in termedia, P. nigrescens and P. corporis all expressed a DnaK homologue , The P. nigrescens DnaK was of a similar molecular mass to E. coli Dn aK (70 kDa), whilst those of P. intermedia and P, corporis were approx imately 69 kDa, DnaJ homologues were expressed in each species; howeve r, no homologue of GrpE was detected, P. intermedia DnaK was purified to homogeneity by ion-exchange and affinity-chromatography, and was sh own to restore activity of denatured luciferase, This molecular chaper one activity was enhanced by E. coli DnaJ and GrpE which are component s of the Hsp70 molecular chaperone machine. (C) 1998 Federation of Eur opean Microbiological Societies. Published by Elsevier Science B.V. Al l rights reserved.