Difference between revisions of "Transformation of AA to 5-HPETE"

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[[Welcome to the In-Silico Model of Cutaneous Lipids Wiki | Return to overview]]
 
[[Welcome to the In-Silico Model of Cutaneous Lipids Wiki | Return to overview]]
  
ALOX5 encodes the protein 5-LOX, which is responsible for the generation of 5-HPETE. This protein shuttles between the cytoplasm and the nucleus and has been detected in the nucleus matrix, the nucleus membrane, the peripheral membrane and the cytoplasm.
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ALOX5 encodes the protein 5-LOX, which is responsible for the generation of 5-HPETE. The formation of the unstable hydroperoxy fatty acids (HPETE) begins with the abstraction of a hydrogen radical at the allylic position between two double bonds. The structure undergoes a rearrangement reaction which results in the formation of a conjugated diene system. The insertion of molecular oxygen and a hydrogen leads to the formation of the final structure, a hydroperoxy fatty acid.  
 
 
The formation of the hydroperoxy fatty acids begins with the abstraction of a hydrogen radical at the allylic position between two double bonds. The structure undergoes a rearrangement reaction which results in the formation of a conjugated diene system. The insertion of molecular oxygen and a hydrogen leads to the formation of the final structure, a hydroperoxy fatty acid.
 
 
 
5-LOX activity in the skin remains a mystery. The enzyme has a low levels of activity in cutaneous cells, but products of the pathway such as leukotrienes and 5-HETE are always detected in human skin tissue (Breton, Woolf et al. 1996). As with various prostaglandins found in the compartment, it has been suggested that the detected 5-LOX metabolites are as a result of infiltrating cells from the vascular compartment (Kowal-Bielecka, Distler et al. 2001, Kanaoka and Boyce 2004).  
 
  
 
== Reaction ==
 
== Reaction ==

Latest revision as of 08:17, 21 August 2019

Return to overview

ALOX5 encodes the protein 5-LOX, which is responsible for the generation of 5-HPETE. The formation of the unstable hydroperoxy fatty acids (HPETE) begins with the abstraction of a hydrogen radical at the allylic position between two double bonds. The structure undergoes a rearrangement reaction which results in the formation of a conjugated diene system. The insertion of molecular oxygen and a hydrogen leads to the formation of the final structure, a hydroperoxy fatty acid.

Reaction

R11 AA - HPETE5.jpg

Chemical equation

 PGH2 \rightleftharpoons 5-HPETE

Rate equation

R11.PNG

Parameters

Kms

Literature values
Value Units Species Notes Weight Reference
5.10E-03  mM Human Expression Vector: Baculovirus, Sf9 insect cells

Enzyme: Recombinant 5-Lipoxygenase pH: 5.6 Temperature:37

256 [1]
1.20E-02  mM Human Expression Vector: Polymorphonuclear Leukocytes

Enzyme: 5-Lipoxygenase pH:7.5 Temperature: 22

512 [2]
6.31E-02  mM Human Expression Vector: Polymorphonuclear Leukocytes

Enzyme: 5-Lipoxygenase pH:7.5 Temperature: 22

512 [3]
Description of the 5-LOX Kms distribution
Mode (mM) Confidence Interval Location parameter (µ) Scale parameter (σ)
1.27E-02 2.74E+00 -3.76E+00 7.73E-01
The estimated probability distribution for 5-LOX 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.

Kmp

Description of the 5-LOX Kmp distribution
Mode (mM) Location parameter (µ) Scale parameter (σ)
1.25E-02 -3.63E+00 8.68E-01
The estimated probability distribution for 5-LOX 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.


kcat

Literature values
Value Units Species Notes Weight Reference
1500 + 75 per minute Potato Expression Vector:Potato Tubers

Enzyme: 5-Lipoxygenase pH:5.5 Temperature: 23

16 [4]
Description of the 5-LOX kcat distribution
Mode (min-1) Confidence Interval Location parameter (µ) Scale parameter (σ)
1.50E+03 1.05E+00 7.31E+00 4.99E-02
The estimated probability distribution for 5-LOX 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

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

Literature values
Value Units Species Notes Weight Reference
97.3  ppm Human Expression Vector: Lung

Enzyme: 5-LOX pH: 7.5 Temperature: 37 °C

1024 [5]
49.8  ppm Human Expression Vector: Esophagus

Enzyme: 5-LOX pH: 7.5 Temperature: 37 °C

1024 [6]
31.9  ppm Human Expression Vector: Oral Cavity

Enzyme: 5-LOX pH: 7.5 Temperature: 37 °C

1024 [6]
Description of the 5-LOX concentration distribution
Mode (ppm) Mode (mM) Confidence Interval Location parameter (µ) Scale parameter (σ)
4.96E+01 2.74E-04 1.60E+00 4.09E+00 4.28E-01
The estimated probability distribution for 5-LOX 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.

Keq

Literature values
Gibbs Free Energy Change Units Species Notes Weight Reference
(-15.9) - 18.01 kcal/mol Soybean Expression Vector: Soybean

Enzyme: Lipoxygenase-1 pH:Not stated Temperature: Not stated

8 [7]
(-69.979996) kcal/mol Not stated Estimated

Enzyme: 5-Lipoxygenase Substrate: Arachidonate Product: 5-HPETE pH: 7.3 ionic strength: 0.25

64 [8]
Description of the 5-LOX Keq distribution
Mode Confidence Interval Location parameter (µ) Scale parameter (σ)
2.27E+51 1.00E+01 1.19E+02 8.90E-01
The estimated probability distribution for 5-LOX 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.

References


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