Emelyanov Victor V, Loukianov Evgeny V
Gamaleya Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
IUBMB Life. 2004 Apr;56(4):215-9. doi: 10.1080/15216540410001699321.
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.
