TABLE 2.

K_m and V_max values for the metabolism of some 5S-hydroxy fatty acids by 5-HEDH-containing U937 cell microsomes Various concentrations of 5-hydroxy fatty acids were incubated with U937 cell microsomes (15 μg/ml protein) for 10 min at 37°C. The amounts of 5-oxo products formed were determined by RP-HPLC as shown in Table 1. The values were determined by nonlinear regression using GraFit software and are means ± S.E. (n = 5).

Substrate	Km	Vmax
	nM	pmol / min / mg
5h-16:2	435 ± 114	383 ± 42
5h-18:2	275 ± 99	445 ± 59
Δ6,8,11-5h-20:3	436 ± 158	608 ± 66
5-HETE	516 ± 190	1062 ± 147
5h-20:5	679 ± 151	872 ± 146