Table 1. Kinetic Parameters for the Reduction of Q1, Q0, and IDE at the Hydrophilic, Flavin Site in Complex I, Determined by Fitting Experimental Data to the Ping-Pong and Ping-Pong-Pong Mechanisms.
| Ping-Pong Mechanism | ||||||
|---|---|---|---|---|---|---|
| KNADHM (μM) | kNADHcat (s−1) | KNADHRed (μM) | KQM (μM) | kQcat (s−1) | LSQE/LSQEmin | |
| Q1 | 94 | 2700 | 200 | 354 | 56.6 | 2.9 |
| Q0 | 94 | 2700 | 200 | 292 | 15.2 | 1.2 |
| IDE | 94 | 2700 | 200 | 5225 | 660 | 1.7 |
| Q1 | 94 | 2700 | 70 | 200 | 47.4 | 1 |
| Q0 | 94 | 2700 | 300 | 345 | 16.2 | 1 |
| IDE | 94 | 2700 | 3001 | 3770 | 450 | 1 |
| Ping-Pong-Pong Mechanism | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| KNADHM (μM) | kNADHcat (s−1) | KNADHRed (μM) | KNADHSemi (μM) | KSQM (μM) | kSQcat (s−1) | KSQM2 (μM) | kSQcat2 (s−1) | LSQE/LSQEmin | |
| Q1 | 94 | 2700 | 200 | 200 | 354 | 113.2 | 354 | 113.2 | 2.9 |
| Q0 | 94 | 2700 | 200 | 200 | 292 | 30.4 | 292 | 30.4 | 1.2 |
| IDE | 94 | 2700 | 200 | 200 | 5225 | 1320 | 5225 | 1320 | 1.7 |
| Q1 | 94 | 2700 | 300 | 70 | 205 | 500a | 205 | 50.3 | 1 |
| Q0 | 94 | 2700 | 300 | 70 | 250 | 14.2 | 250 | 242.5 | 1 |
| IDE | 94 | 2700 | 300 | 70 | 3880 | 479 | 3880 | 20000a | 1.1 |
a
Value increases indefinitely without significantly affecting the LSQE value.