A <i>B. pertussis</i> Vag8 mutant fails to bind C1inh.

<p><b>A</b> Standard immunoblot analysis showing surface binding of the 104-kDa C1inh protein to whole bacteria incubated in serum; <b>B</b> Far-Western analysis testing for the interaction of C1inh with a ca. 95- to 100-kDa factor of <i>B. pertussis</i>. The left and right panels in <b>A</b> and <b>B</b> show the results with BP338Vag8⁻ (<i>vag8</i>::pEG7-Vag8) and BP338BipA⁻ (<i>bipA</i>::pTEN34), respectively. <b>C</b> Immunoblot probed for the BvgAS-activated autotransporter protein BrkA. <b>D</b> Immunoblot analysis showing surface binding of C1inh to wild type <i>B. pertussis</i> (BP338) and the BP338Vag8⁻ mutant complemented with pVag8. BP338Vag8⁻ complemented with control plasmids pBBR1MCS2 (empty vector) or pBrkA (vector with the <i>brkA</i> gene under control of P<i>_cpn10</i>) did not bind C1inh.