TABLE 1.

Summary of the coordination and spin state assignment of ferric and ferrous NOS and P450

Form	Coordination	ν4 (cm−1)	ν3 (cm−1)	ν10/νvinyl (cm−1)	Reference
Fe3+ SANOSa	5C HS	1373	1489	1626	A
Fe3+ SANOS/Arg*	6C LS	1373	1503	1639	A
Fe3+ nNOS/H4B	5C HS	1369	1488	1624	B
Fe3+ nNOS (no pterin)	5C HS	1370	1488	1623	B
Fe3+ eNOS/H4B	5C HS	1371	1487	1623	C
Fe3+ P450cam	6C LS	1371	1502	n.d.	D
Fe3+P450cam/camphor	5C HS	1370	1488	n.d.	D
	6C LS	1373	1500	1638
	6C LS	1373	1503	1635
	5C HS	1368	1488	1623
	6C LS	1372	n.d.	1637
Fe2+ SANOS	5C HS	1349	1467	1602/1619	A
Fe2+ SANOS/Arg	5C HS	1349	1467	1602/1619	A
Fe2+ nNOS/H4B	5C HS	1347	1466	1600/1617†	B
Fe2+ nNOS (no pterin) (420 form)	6C LS	1360(sh)	1490	1615	B
	6C LS	1360	1467
	5C HS	n.d.

In “Reference” column, A, this work; B, Wang et al., 1995; C, Rodriguez-Crespo et al., 1997; and D, Wells et al., 1992. n.d., not determined; sh, shoulder.

^*We also obtained the spectrum of ferric SANOS/H₄B. The heme is mostly 5-coordinate and high-spin as we detect only the ν₃ line at 1489 cm⁻¹. However, the quality of the spectrum is poor due to fluorescence of the sample caused by H₄B.

^†The values were not specifically assigned to the 5-coordinate or the 6-coordinate form.