Skip to main content

Table 1 Human ADH and ALDH family members involved in the metabolism of ethanol

From: Effect of the allelic variants of aldehyde dehydrogenase ALDH2*2 and alcohol dehydrogenase ADH1B*2on blood acetaldehyde concentrations

Enzyme

Class

Gene

locus

Allelic

Variant

Subunit

composition

K m

(mM)

V max

(U/mg)

Vmax/Km

(U/mg/mM)

ADH

I

ADH1A

 

αα

5.2

0.24

0.047

  

ADH1B

ADH1B*1

β1β1

0.016

0.18

12

   

ADH1B*2

β2β2

1.9

4.8

2.6

   

ADH1B*3

β3β3

53

3.2

0.060

  

ADH1C

ADH1C*1

γ1γ1

0.11

0.81

 
   

ADH1C*2

γ2γ2

0.061

0.47

 
 

II

ADH2

 

ππ

23

0.30

0.013

 

III

ADH3

 

χχ

3,400

0.83

 
 

IV

ADH4

 

μμ(σσ)

58

11

0.19

ALDH

I

ALDH1A1

 

Tetramer

0.033

0.63

19

 

II

ALDH2

ALDH2*1

Tetramer(E4)

0.00020

0.60

3,000

   

ALDH2*2

Tetramer(K4)

0.0046

0.017

3.6

  1. Enzyme activity was determined in 0.1M sodium phosphate, at pH 7.5 and 25°C. Samples contained 0.5 mM nicotinamide adenine dinucleotide (NAD; ie a cytosolic oxidised coenzyme concentration in hepatocytes), and various concentrations of ethanol for alcohol dehydrogenase (ADH) or of acetaldehyde for aldehyde dehydrogenase (ALDH). γ1γ12γ2 and χχ exhibit negative and positive cooperativity, respectively; hence they do not have a Km and the values shown are S0.5. Enzyme activity units (U) are expressed as micromoles NADH formed per minute under the assay conditions. Data are from Yin and Agarwal,[1] Yin et al [9]. and Lee et al [10].