TABLE 2.
Biological activities of mutated LukF-PV and HlgB combined with LukS-PV, HlgA, or HlgC
| F proteinc | S protein activity (time [min])
|
||||||
|---|---|---|---|---|---|---|---|
| Ca2+ entrya
|
Ethidium entryb
|
||||||
| LukS-PV | HlgA | HlgC | LukS-PV | HlgA | HlgC | ||
| LukF-PV | 100 (2.5) | 91 ± 3 (5) | 61 ± 7 (5) | 8.4 ± 0.4 (1) | 5.2 ± 0.2 (2) | 4.2 ± 0.3 (4) | |
| LukF-PV (2 nM) | 92 ± 2 (7.5) | 80 ± 9 (7.5) | 36 ± 19 (10) | 4.7 ± 0.2 (3) | 4.8 ± 0.2 (6) | 2.5 ± 0.2 (7) | |
| F Gly130Asp | 83 ± 4 (10) | 71 ± 10 (10) | 0 | 1.4 ± 0.1 (10) | 2.8 ± 0.2 (6) | 0 | |
| F Gly131Asp | 95 ± 3 (5) | 91 ± 1 (5) | 30 ± 5 (5) | 2.6 ± 0.1 (6) | 4.9 ± 0.3 (3) | 0.8 ± 0.2 (6) | |
| F ΔAsn123-Gly127 | 56 ± 9 (10) | 91 ± 11 (10) | 98 ± 21 (7.5) | 1.1 ± 0.1 (20) | 3.1 ± 0.3 (6) | 2.6 ± 0.2 (3) | |
| F ΔIle124-Asn126 | 96 ± 7 (2.5) | 102 ± 17 (5) | 109 ± 20 (2.5) | 3.4 ± 0.3 (4) | 5.1 ± 0.2 (3) | 7.0 ± 0.5 (1) | |
| F ΔIle124-Ser129 | 0 | 0 | 0 | 0 | 0 | 0 | |
| F ΔSer125-Gly127 | 99 ± 3 (2.5) | 93 ± 3 (5) | 96 ± 2 (2.5) | 9.7 ± 0.2 (1) | 5.0 ± 0.2 (2) | 10.2 ± 0.2 (1) | |
| F ΔSer125-Leu128 | 90 ± 13 (5) | 90 ± 4 (5) | 92 ± 6 (2.5) | 2.7 ± 0.1 (5) | 4.8 ± 0.3 (3) | 5.6 ± 0.4 (1) | |
| F ΔGly127-Ser129 | 101 ± 7 (2.5) | 89 ± 4 (5) | 88 ± 3 (2.5) | 4.9 ± 0.4 (2) | 4.6 ± 0.2 (2) | 7.0 ± 0.4 (1) | |
| F Ser129Ala | 97 ± 1 (2.5) | 90 ± 2 (5) | 64 ± 7 (5) | 8.2 ± 0.2 (1) | 4.9 ± 0.1 (2) | 5.0 ± 0.2 (4) | |
| HlgB | 88 ± 5 (5) | 89 ± 4 (2.5) | 78 ± 6 (2.5) | 5.9 ± 0.4 (1) | 3.8 ± 0.3 (2) | 3.5 ± 0.2 (2) | |
| HlgB (0.5 nM) | 44 ± 16 (10) | 83 ± 7 (5) | 59 ± 12 (7.5) | 3.0 ± 0.3 (3) | 3 ± 0.4 (2) | 3.0 ± 0.2 (3) | |
| HlgB Gly130Asp | 85 ± 6 (7.5) | 87 ± 2 (5) | 30 ± 11 (2.5) | 3.5 ± 0.4 (2) | 2.9 ± 0.3 (3) | 0.9 ± 0.1 (7) | |
a
Fluorescence maxima as percentages from control ± standard deviations; time (minutes) necessary to reach the maximal fluorescence is shown in parentheses.
b
Rate of ethidium entry as a variation of fluorescence/minute; lag time (minutes) before the increase of fluorescence is shown in parentheses.
c
If not otherwise specified, protein concentrations were as follows: LukS-PV, 1 nM; HlgA, 2 nM; HlgC, 1 nM; LukF-PV as well as all LukF-PV mutants, 40 nM; HlgB and HlgB G130D, 5 nM.