Table 2.
Initial rates for both inactivation and cleavage of full length sACE-1 by M-chelate-lisinopril complexes and reduction potentials of the attached M-chelates
| complexa | initial rates for inactivation {and cleavage} of full length sACE-1 (% sACE-1 / min) by M-chelate-lisinopril complexes and coreactantsb |
red. potential vs. NHE of M-chelate (mV)c |
|||
|---|---|---|---|---|---|
| ascorbate + H2O2 |
ascorbate | H2O2 | none | ||
| Fe-NTA-lisin | 0.06 ± 0.01 | 0.01 ± 0.02 | 0.01 ± 0.03 | 0.02 ± 0.02 | 464 |
| Co-NTA-lisin | 0.04 ± 0.04 | < 0.03 | 0.01 ± 0.02 | 0.04 ± 0.04 | 274 |
| Ni-NTA-lisin | 0.09 ± 0.01 | < 0.04 | < 0.02 | < 0.03 | 176 |
| Cu-NTA-lisin | 0.08 ± 0.02 | 0.03 ± 0.03 | 0.01 ± 0.03 | 0.03 ± 0.04 | 215 |
| Co-GGH-lisin | 0.24 ± 0.02 {< 0.2} | 0.07 ± 0.03 | < 0.06 | 0.02 ± 0.03 | −119 |
| Ni-GGH-lisin | 0.20 ± 0.04 {< 0.05} | 0.11 ± 0.03 {0.12 ± 0.08} | 0.10 ± 0.05 | 0.04 ± 0.07 | 1000 |
| Cu-GGH-lisin | 4.7 ± 0.2 {2.6 ± 0.6} | 3.1 ± 0.2 {< 0.09} | 0.9 ± 0.2 {0.6 ± 0.1} | 0.09 ± 0.04 | 1038 |
| Fe-EDTA-lisin | 0.07 ± 0.02 | 0.19 ± 0.03 {< 0.1} | 0.03 ± 0.03 | 0.02 ± 0.04 | 391 |
| Co-EDTA-lisin | 0.6 ± 0.2 {< 0.08} | 0.05 ± 0.01 | 0.8 ± 0.2 {0.29 ± 0.09} | 0.03 ± 0.03 | 146 |
| Ni-EDTA-lisin | 0.07 ± 0.03 | 0.02 ± 0.02 | 0.05 ± 0.03 | 0.03 ± 0.02 | 172 |
| Cu-EDTA-lisin | 0.14 ± 0.02 | 0.10 ± 0.03 {0.28 ± 0.07} | 0.15 ± 0.06 {< 0.09} | 0.06 ± 0.04 | 47 |
| Fe-DOTA-lisin | 0.75 ± 0.09 {0.43 ± 0.08} | 0.04 ± 0.02 | 1.9 ± 0.4 {< 0.04} | 0.08 ± 0.03 | 396 |
| Co-DOTA-lisin | 0.51 ± 0.04 {0.4 ± 0.2} | 0.14 ± 0.05 {0.1 ± 0.1} | 0.04 ± 0.03 | 0.04 ± 0.03 | 142 |
| Ni-DOTA-lisin | 0.75 ± 0.08 {< 0.01} | 0.03 ± 0.02 | 0.13 ± 0.01 {< 0.1} | 0.01 ± 0.04 | −35 |
| Cu-DOTA-lisin | 0.73 ± 0.03 {< 0.1} | 0.14 ± 0.03 {0.2 ± 0.1} | 0.03 ± 0.04 | 0.05 ± 0.05 | 180 |
| None | 0.02 ± 0.05 {0.17 ± 0.07} | 0.03 ± 0.03 {0.2 ± 0.2} | < 0.03 {< 0.2} | 0.04 ± 0.02 | |
a
lisin = lisinopril.
b
For reactions with initial rates of inactivation (monitored by fluorogenic substrate cleavage) that were above background (shown in bold), initial rates of cleavage of full length sACE-1 (monitored by SDS-PAGE) are listed for comparison (shown in brackets).
c
Reduction potentials of the M-chelate domains were determined previously;12 redox couples are 3+/2+ for Fe, Co, Ni-ATCUN, and Cu-ATCUN complexes and 2+/1+ for all other Ni and Cu complexes.