Table 1.

Heme proteins that have incomplete heme saturation when they are expressed in cells or tissues outside the circulation

Heme protein	System	References
Soluble guanylyl cyclase	Cells and tissues	[25], [31] and refs. therein
Trp dioxygenase	Cells and tissues	[6], [7], [32]
Indoleamine dioxygenase	Cells	[57], [25] and refs. therein
Hemoglobin α, β, γ	Cells and tissues	[31], [70]
Myoglobin	Cells and tissues	[31,70]
Cytochrome P450	Cells and tissues	[58]
Myeloperoxidase	Cells	[31]
NADPH oxidase 5	Cells	[71]
Ascorbate peroxidasea	Cells	[72]
Horseradish peroxidasea	Cells	[72]

^aplant enzymes were expressed in mammalian cells