TABLE 1.
Activity measurements of 11 double cysteine mutants that include the L subunit lateral helix
| Mutation | Distancea | Deamino-NADH oxidase activityb | % Deamino-NADH oxidase activityc | Ferricyanide reductase activityb | % Ferricyanide reductase activityc |
|---|---|---|---|---|---|
| Å | nmol/mg protein/min | nmol/mg protein/min | |||
| pBA400 | 165 ± 48 (15)c | 100 | 710 ± 200 (8)c | 100 | |
| A557C(L) + A307C(M) | 4.92 | 137 ± 29 (5) | 83 | 744 ± 45 | 105 |
| K561C(L) + A307C(M) | 4.22 | 133 ± 11 (5) | 81 | 770 ± 55 | 108 |
| L565C(L) + P239C(M) | 5.43 | 160 ± 59 (5) | 97 | 765 ± 15 | 108 |
| K561C(L) + D163C(M) | 12.05 | 270 ± 10 (2) | 164 | 797 ± 12 | 112 |
| N570C(L) + D163C(M) | 13.63 | 161 ± 3 (2) | 98 | 643 ± 22 | 91 |
| N570C(L) + D246C(M) | 10.86 | 250 ± 12 (2) | 151 | 853 ± 15 | 120 |
| V574C(L) + D246C(M) | 16.12 | 230 ± 14 (2) | 139 | 905 ± 13 | 128 |
| K581C(L) + S290C(N) | 6.22 | 138 ± 5 (2) | 84 | 690 ± 43 | 97 |
| L594C(L) + L225C(N) | 4.46 | 86 ± 11 (2) | 52 | 651 ± 21 | 92 |
| S597C(L) + L225C(N) | 5.7 | 161 ± 5 (2) | 98 | 940 ± 43 | 132 |
| D546C(L) + D241C(L) | 13.04 | 230 ± 5 (2) | 139 | 745 ± 62 | 105 |
| BA14 | 18 ± 3 (2) | 11 | 84 ± 2 | 12 |
a Distance between the α-carbons of the native residues.
b Activity was measured in membrane preparations as described under “Experimental Procedures.” The means, S.D., and number of measurements (parentheses) are shown. For ferricyanide reductase activity, two-three measurements were made except for wild type and BA14.
c Activity is expressed as a percentage of the wild type rate.