Table 1. Kinetic parameters for the reactions of wild-type and Y103F variant human Mb with H₂O₂ and added C_18:2,n−6.

Reactions were performed in 100 mM phosphate buffer (pH 7.4) maintained at 37 °C with Mb (final concentration, 50 μM), H₂O₂ (250 μM) and 18:2 (0–9.5 mM). Where possible, kinetic data are reported as the mean±S.D. of n≥3 independent analyses. Enantiomers of 9- and 13-HODE were separated by normal-phase chiral HPLC as described in the Experimental section. Product distributions for 9- and 13-HODEs are presented as an average obtained over all conditions studied.

Protein	Km (mM)	Vmax (pmol/min−1·nmol Mb protein−1)	Yield 9(S):9(R)	Yield 13(S):13(R)	Source
Wild-type sperm whale Mb	6±1	224±30	81:16	−	[14]
Wild-type human Mb	4.3±0.8	238±10	94:6	18:82	Present study
Y103F Mb	8.6±0.3*	148±19*	71:29*	17:83	Present study
H2O2 alone	−	−	49:51*	25:75	Present study

* Significantly different from corresponding value for wild-type Mb (P<0.05).