TABLE 2.
Frequencies of the νFe-CO and νC-O lines of various NOS, P450cam, and chloroperoxidase (CPO)
| Frequency (cm−1)
|
|||||
|---|---|---|---|---|---|
| Protein | No. | νFe-CO (13C18O) | δFe-C-O (13C18O) | νC-O (13C18O) | Reference |
| SANOS | 1 | 482 (470)* | 560 (543)† | 1949 (1857)‡ | This work |
| 2 | 497 (481)* | 1930 (1843)‡ | |||
| SANOS/Arg | 3 | 504 (496) | 567 (548) | 1917 (1830) | This work |
| nNOS/H4B | 4 | 487 (∼477) | 562 (544) | 1949 (1856) | A |
| 5 | 501 (∼491) | 1930 (1837) | |||
| nNOS/H4B/Arg | 6 | 503 (493) | 565 (546) | 1929 (1841) | A |
| iNOS/H4B | 479¶ | 560 (550) | 1945 (1846)§ | B | |
| 499¶ | |||||
| iNOS/H4B/Arg | 7 | 512 (499) | 567 (551) | 1906 (1819) | B |
| eNOS/H4B/Arg | 512 | 567 | N.D. | B | |
| P450cam (substrate-free) | 8 | 464 | 556 | 1963 | C |
| P450cam/camphor | 9 | 481 | 558 | 1940 | C |
| CPO pH 6.1 | 14 | 485 (474) | 560 (538) | 1957.5 (1872) | A |
Numbers in “No.” column refer to data points in Fig. 7. In “Reference” column, A, Wang et al. (1997); B, Fan et al. (1997); C, Uno et al. (1985) and Wells et al. (1992).
The best fit to the data for the deconvolution of the broad 489 cm−1 band with 12C16O identifies a line at 482 cm−1 that we assign to a νFe-CO mode and a line at 497 cm−1 that we assign as a νFe-CO mode plus a less intense heme mode at 498 cm−1. This assignment is confirmed with deconvolution of the 13C18O spectrum where the broad line centered at 475 cm−1 is resolved in two νFe-CO at 470 cm−1 and 481 cm−1, respectively, and a heme mode at 498 cm−1.
The bending mode is not assigned to one set of νFe-CO and νC-O modes or the other.
The precise position of the bands was obtained from spectral deconvolution.
The undeconvoluted νFe-CO line is centered at 487 cm−1 and shifts to 474 cm−1 with 13C18O.
Broad band.