Table 1.

Cytotoxic activities of the recombinant CyaA proteins. The binding and internalization of CyaA and different variants were assayed on sheep erythrocytes as described in the Experimental Section. The proteins in 6m urea were directly diluted (to a final concentration of 5.6 nm) in sheep erythrocyte suspensions in buffer B. Bound and internalized AC activities for each recombinant protein is expressed as % of that measured with the wild‐type CyaA toxin and represent the average values of at least three independent measurements. The substituted residues are indicated in bold letters for each CyaA variants

Proteins	Sequence of the 454–484 region of CyaA recombinant proteins	Cell‐bound AC activity [% of wt]	Internalized AC activity [% of wt]	Number of replicates
CyaAwt	ASAHWGQRALQGAQAVAAAQRLVHAIALMTQ	100	100	17
CyaAMut1	‐‐‐‐‐‐‐E‐A‐‐‐‐‐‐‐‐‐‐EA‐S‐A‐‐‐‐‐	96 ± 24	4 ± 2	5
CyaAR 12 E	‐‐‐‐‐‐‐E‐‐‐‐‐‐‐‐‐‐‐‐E‐‐‐‐‐‐‐‐‐‐	106 ± 28	3 ± 3	9
CyaAR 12 Q	‐‐‐‐‐‐‐Q‐‐‐‐‐‐‐‐‐‐‐‐Q‐‐‐‐‐‐‐‐‐‐	107 ± 36	102 ± 7	3
CyaAR 12 A	‐‐‐‐‐‐‐A‐‐‐‐‐‐‐‐‐‐‐‐A‐‐‐‐‐‐‐‐‐‐	112 ± 18	112 ± 7	3
CyaAR 12 K	‐‐‐‐‐‐‐K‐‐‐‐‐‐‐‐‐‐‐‐K‐‐‐‐‐‐‐‐‐‐	110 ± 17	114 ± 19	3
CyaAMut2	‐‐‐‐‐‐‐‐‐A‐‐‐‐‐‐‐‐‐‐‐A‐S‐A‐‐‐‐‐	112 ± 17	4 ± 3	6
CyaAMut3	‐‐‐‐A‐‐‐‐A‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐	94 ± 9	106 ± 13	3
CyaAMut4	‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐A‐S‐A‐‐‐‐‐	110 ± 19	15 ± 6	8
CyaAMut5	‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐S‐A‐‐‐‐‐	113 ± 10	72 ± 12	5
CyaAMut6	‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐A‐‐‐‐‐	97 ± 33	99 ± 7	3
CyaAMut7	‐‐‐‐A‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐A‐‐‐‐‐	107 ± 34	62 ± 7	5