Transformation of 5-HETE to 5-OXO-ETE

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5-HETE is oxidised by 5-hydroxyeicosanoid dehydrogenase (5-HEDH) to 5-oxo-ETE . 5-HEDH is a microsomal enzyme which catalyses the conversion of the C5 alcohol to a ketone by transferring the hydrogen cation to NADP+ via a ping-pong mechanism .

Reaction

Chemical equation

$5-HETE \rightleftharpoons 5-Oxo-ETE$

Rate equation

Parameters

Note that there was limited availability of kinetic data for this specific enzyme, therefore parameters for general alcohol dehydrogenase (ADH) was used when non were available.

K_ms

Literature Values

Value	Units	Species	Notes	Weight	Reference
0.0006	mM	Unkown	Follows a ping-pong mechanism by binding with NADP+, transforming it to NADPH and releasing it before binding 5S-HETE.	64
0.00067	mM	Human Cell lines	Follows a ping-pong mechanism by binding with NADP+ (Km 139 nM), transforming it to NADPH (inhibited by NADPH (Ki 224 nM)) and releasing it before binding 5S-HETE. Method: In vitro Organism: Human Expression vector: U937 and HL-60 cell lines Enzyme:5-HEDH pH: 7.4 Temperature: 37 ◦C	2048
0.000516 ± 0.00019	mM	Human Cell lines	Method: In vitro Organism: Human Expression vector: U937 Enzyme:5-HEDH pH: 7.4 Temperature: 37 ◦C	2048

Description of the 5-HEDH Kms distribution

Mode (mM)	Confidence Interval	Location parameter (µ)	Scale parameter (σ)
6.34E-04	1.63E+01	-6.31E+00	1.03E+00

The estimated probability distribution for 5-HEDH Kms. The value and weight of the literature values used to define the distribution are indicated by an orange dashed line. The x axis is plotted on a log-scale.

K_mp

This is a “Dependent parameter”, meaning that the log-normal distribution for this parameter was calculated using multivariate distributions (this is discussed in detail here). As a result, no confidence interval factor or literature values were cited for this parameter.

Description of the 5-HEDH Kmp distribution

Mode (mM)	Location parameter (µ)	Scale parameter (σ)
1.14E+04	1.09E+01	1.25E+00

The estimated probability distribution for 5-HEDH Kmp. The value and weight of the literature values used to define the distribution are indicated by an orange dashed line. The x axis is plotted on a log-scale.

V_max

Literature values

Value	Units	Species	Notes	Reference
0.54 ± 0.30	pmol/ mi mg	Human Cell lines - Neutrophils	Method: In vitro Organism: Human Expression vector: U937 and HL-60 cell lines Enzyme:5-HEDH pH: 7.4 Temperature: 37 ◦C
0.40 ± 0.12	pmol/ mi mg	Human Cell lines - U937	Method: In vitro Organism: Human Expression vector: U937 and HL-60 cell lines Enzyme:5-HEDH pH: 7.4 Temperature: 37 ◦C

k_cat

Literature values

Value	Units	Species	Notes	Weight	Reference
11640 ± 840	min-1	Yokenella	Method: In vitro Organism: Human Expression vector: E Coli Enzyme: pH: 6.5 Temperature: 65 ◦C Substrate: NADPH	128

Description of the 5-HEDH kcat distribution

Mode (min-1)	Confidence Interval	Location parameter (µ)	Scale parameter (σ)
1.15E+04	4.02E+01	1.09E+01	1.25E+00

The estimated probability distribution for 5-HEDH kcat. The value and weight of the literature values used to define the distribution are indicated by an orange dashed line. The x axis is plotted on a log-scale.

Enzyme concentration (Using ADH5 abundance data)

To convert the enzyme concentration from ppm to mM, the following equation was used.

Literature values

Value	Units	Species	Notes	Weight	Reference
490	ppm	Human	Expression Vector: Skin Enzyme: ADH5 pH: 7.5 Temperature: 37 °C	2048
625	ppm	Human	Expression Vector: Oral Cavity Enzyme: ADH5 pH: 7.5 Temperature: 37 °C	1024
728	ppm	Human	Expression Vector: Esophagus Enzyme: ADH5 pH: 7.5 Temperature: 37 °C	1024
11.5	ppm	Human	Expression Vector: Skin Enzyme: ADH5 pH: Unknown Temperature: Unknown	2048

Description of the 5-HEDH concentration distribution

Mode (ppm)	Mode (mM)	Confidence Interval	Location parameter (µ)	Scale parameter (σ)
4.88E+02	2.70E-03	6.37E+00	7.49E+00	1.14E+00

The estimated probability distribution for 5-HEDH concentration. The value and weight of the literature values used to define the distribution are indicated by an orange dashed line. The x axis is plotted on a log-scale.

K_eq

Literature values

Gibbs Free energy	Units	Species	Notes	Weight	Reference
1.29	kcal/mol	Arabidopsis thaliana col	Same reaction, no prediction available for 5-HEDH on Metacyc Estimated Enzyme: ω-hydroxy fatty acid ω-alcohol dehydrogenase Substrate: 18-hydroxyoleate Product: 18-oxo-oleate pH: 7.3 ionic strength: 0.25	64

Description of the 5-HEDH Keq distribution

Mode	Confidence Interval	Location parameter (µ)	Scale parameter (σ)
1.12E-01	1.00E+01	-1.39E+00	8.91E-01

The estimated probability distribution for 5-HEDH Keq. The value and weight of the literature values used to define the distribution are indicated by an orange dashed line. The x axis is plotted on a log-scale.