EXPRESSION AND FUNCTIONAL-CHARACTERIZATION OF THE CLPC GENE OF MYCOBACTERIUM-LEPRAE - CLPC PROTEIN ELICITS HUMAN-ANTIBODY RESPONSE

This paper reports the expression of a previously described gene [Nath and Laal, Nucleic Acids Res. 18 (1990) 4935], currently identified as the clpC gene of Mycobacterium leprae, using an in vitro rabbit retic ulocyte lysate-coupled transcription/translation system. The produced protein moved as a 95-kDa band on SDS-PAGE. An additional band of 79 k Da was seen which may have resulted from a GTG codon downstream to the initiating ATG in the clpC sequence. A threefold increase in synthesi s of the 95-kDa protein was achieved by altering the translation codon context sequence of the ATG start codon. The ClpC (caseinolytic prote ase C) amino acid sequence, which contained two nucleotide-binding sit es, exhibited in vitro ATP binding. Of functional significance was its immunoreactivity in human subjects with mycobacterial infection. Lepr osy and tuberculosis patients with active disease had antibodies which recognised ClpC in dot ELISA.