| Abstrakt: |
Allelic genes from three Rickettsia prowazekii strains encoding parvulin-like protein (Plp), a heat-modifiable 29.5 kDa major outer membrane protein, were earlier cloned into expression vector pQE 30. In this work, recombinant proteins were overproduced in E. coli , purified, and found to exhibit an expected peptidyl-prolyl cis/trans isomerase activity of a parvulin type in vitro with oligopeptide substrates. Native polypeptide of prototype virulent Breinl strain is known to differ by SDS - PAGE mobility from those of both vaccine Madrid E and virulent EVir isolates. Being different in electrophoretic behavior, heat-unmodified forms of the three strains were shown to migrate apart from lipopolysaccharides. A EVir Plp gene was sequenced, and deduced protein sequence was found to be identical to previously published Breinl and Madrid E. Present data indicate that unknown post-translational modification(s) in rickettsiae are responsible for both interstrain difference and heat-modifiability of Plp. IUBMB Life, 56: 215-219, 2004 [ABSTRACT FROM AUTHOR] |
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