Difference between revisions of "Transformation of AA to 15-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]]
  
An isoform homologous to 12-LOX is the 15-LOX enzyme, which produces both 12 and 15-HETE products (Kuhn and O'Donnell 2006). An area of interest is that the 12 and 15 LOX products of the epidermis and the dermis have reciprocal activity during inflammation, for example 15-HETE reduces the infiltration of inflammatory cells, meanwhile 12-HETE acts as an activator for infiltrating immune cells (Dowd, Kobza Black et al. 1985, Serhan, Jain et al. 2003).
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The genes ALOX15B and ALOX15 encodes the formation of two isoforms of 15-lioxygenase (15-LOX). The gene ALOX15B encodes the formation of 15-LOX-2, which converts AA exclusively into 15(S)-HPETE.  Whereas the gene ALOX15 encodes the 15-LOX-1 protein, which converts AA into both 12(S)-HPETE and 15(S)-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 ==
 
== Reaction ==
  
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! Species
 
! Species
 
! Notes
 
! Notes
 +
! Weight
 
! Reference
 
! Reference
 
|-
 
|-
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pH: 7.5
 
pH: 7.5
 
Temperature: 25
 
Temperature: 25
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|512
 
|<ref name="Jacquot2008"> [http://www.ncbi.nlm.nih.gov/pubmed/18547056 Jacquot C. "Isotope sensitive branching and kinetic isotope effects in the reaction of deuterated arachidonic acids with human 12- and 15-lipoxygenases.'' Biochemistry. 2008 Jul 8;47(27):7295-303. doi: 10.1021/bi800308q. Epub 2008 Jun 12.]</ref>  
 
|<ref name="Jacquot2008"> [http://www.ncbi.nlm.nih.gov/pubmed/18547056 Jacquot C. "Isotope sensitive branching and kinetic isotope effects in the reaction of deuterated arachidonic acids with human 12- and 15-lipoxygenases.'' Biochemistry. 2008 Jul 8;47(27):7295-303. doi: 10.1021/bi800308q. Epub 2008 Jun 12.]</ref>  
 
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pH:7.5  
 
pH:7.5  
 
Temperature: Unspecified
 
Temperature: Unspecified
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|512
 
|<ref name="Jacquot2008b"> [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883171/ Jacquot C. "Synthesis of 11-Thialinoleic Acid and 14-Thialinoleic Acid, Inhibitors of Soybean and Human Lipoxygenases'' Org Biomol Chem. 2008 Nov 21; 6(22): 4242–4252.]</ref>  
 
|<ref name="Jacquot2008b"> [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883171/ Jacquot C. "Synthesis of 11-Thialinoleic Acid and 14-Thialinoleic Acid, Inhibitors of Soybean and Human Lipoxygenases'' Org Biomol Chem. 2008 Nov 21; 6(22): 4242–4252.]</ref>  
 
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pH: 6.7 - 7.3
 
pH: 6.7 - 7.3
 
Temperature: 37
 
Temperature: 37
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|2048
 
|<ref name="Burrall1988"> [http://www.ncbi.nlm.nih.gov/pubmed/2459258 Burrall B. "Enzymatic properties of the 15-lipoxygenase of human cultured keratinocytes.'' J Invest Dermatol. 1988 Oct;91(4):294-7.]</ref>  
 
|<ref name="Burrall1988"> [http://www.ncbi.nlm.nih.gov/pubmed/2459258 Burrall B. "Enzymatic properties of the 15-lipoxygenase of human cultured keratinocytes.'' J Invest Dermatol. 1988 Oct;91(4):294-7.]</ref>  
 
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pH: 6.8
 
pH: 6.8
 
Temperature: 37
 
Temperature: 37
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|512
 
|<ref name="Sloane1995"> [http://www.ncbi.nlm.nih.gov/pubmed/7479689 Sloane D. L. "Conversion of human 15-lipoxygenase to an efficient 12-lipoxygenase: the side-chain geometry of amino acids 417 and 418 determine positional specificity.'' Protein Eng. 1995 Mar;8(3):275-82..]</ref>  
 
|<ref name="Sloane1995"> [http://www.ncbi.nlm.nih.gov/pubmed/7479689 Sloane D. L. "Conversion of human 15-lipoxygenase to an efficient 12-lipoxygenase: the side-chain geometry of amino acids 417 and 418 determine positional specificity.'' Protein Eng. 1995 Mar;8(3):275-82..]</ref>  
 
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[[Image:58.jpg|none|thumb|500px|The estimated probability distribution for 15-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.  ]]
 
[[Image:58.jpg|none|thumb|500px|The estimated probability distribution for 15-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.  ]]
 
 
  
 
===k<sub>cat</sub>===
 
===k<sub>cat</sub>===
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! Species
 
! Species
 
! Notes
 
! Notes
 +
! Weight
 
! Reference
 
! Reference
 
|-
 
|-
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pH: 7.5
 
pH: 7.5
 
Temperature: 25
 
Temperature: 25
 +
|512
 
|<ref name="Jacquot2008"> [http://www.ncbi.nlm.nih.gov/pubmed/18547056 Jacquot C. "Isotope sensitive branching and kinetic isotope effects in the reaction of deuterated arachidonic acids with human 12- and 15-lipoxygenases.'' Biochemistry. 2008 Jul 8;47(27):7295-303. doi: 10.1021/bi800308q. Epub 2008 Jun 12.]</ref>  
 
|<ref name="Jacquot2008"> [http://www.ncbi.nlm.nih.gov/pubmed/18547056 Jacquot C. "Isotope sensitive branching and kinetic isotope effects in the reaction of deuterated arachidonic acids with human 12- and 15-lipoxygenases.'' Biochemistry. 2008 Jul 8;47(27):7295-303. doi: 10.1021/bi800308q. Epub 2008 Jun 12.]</ref>  
 
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Enzyme:15-lipoxygenase-2
 
Enzyme:15-lipoxygenase-2
 
|pH 7, Temperature: 22
 
|pH 7, Temperature: 22
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|rowspan="7"|512
 
|rowspan="7"|<ref name="Wecksler2009"> [http://www.ncbi.nlm.nih.gov/pubmed/18547056  Wecksler A. "Kinetic and Structural Investigations of the Allosteric Site in Human Epithelial 15-Lipoxygenase-2'' Biochemistry, 2009, 48 (36), pp 8721–8730]</ref>  
 
|rowspan="7"|<ref name="Wecksler2009"> [http://www.ncbi.nlm.nih.gov/pubmed/18547056  Wecksler A. "Kinetic and Structural Investigations of the Allosteric Site in Human Epithelial 15-Lipoxygenase-2'' Biochemistry, 2009, 48 (36), pp 8721–8730]</ref>  
 
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===Enzyme concentration ===
 
===Enzyme concentration ===
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 +
To convert the enzyme concentration from ppm to mM, the following [[Common equations#Enzyme concentration (mM)|equation]] was used.
 +
 
{|class="wikitable sortable"  
 
{|class="wikitable sortable"  
 
|+  style="text-align: left;" | Literature values
 
|+  style="text-align: left;" | Literature values
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! Species
 
! Species
 
! Notes
 
! Notes
 +
! Weight
 
! Reference
 
! Reference
 
|-
 
|-
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pH: 7.5
 
pH: 7.5
 
Temperature: 37 °C
 
Temperature: 37 °C
 +
|1024
 
|<ref name="Kim2014"> [http://www.nature.com/nature/journal/v509/n7502/pdf/nature13302.pdf M. Kim ''A draft map of the human proteome'' Nature, 2014 509, 575–581]</ref>
 
|<ref name="Kim2014"> [http://www.nature.com/nature/journal/v509/n7502/pdf/nature13302.pdf M. Kim ''A draft map of the human proteome'' Nature, 2014 509, 575–581]</ref>
 
|-
 
|-
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pH: 7.5
 
pH: 7.5
 
Temperature: 37 °C
 
Temperature: 37 °C
 +
|1024
 
|<ref name="Wilhelm2014"> [http://www.nature.com/nature/journal/v509/n7502/pdf/nature13319.pdf M. Wilhelm ''Mass-spectrometry-based draft of the human proteome'' Nature, 2014 509, 582–587]</ref>
 
|<ref name="Wilhelm2014"> [http://www.nature.com/nature/journal/v509/n7502/pdf/nature13319.pdf M. Wilhelm ''Mass-spectrometry-based draft of the human proteome'' Nature, 2014 509, 582–587]</ref>
 
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|-
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pH: 7.5
 
pH: 7.5
 
Temperature: 37 °C
 
Temperature: 37 °C
 +
|1024
 
|<ref name="Kim2014"> [http://www.nature.com/nature/journal/v509/n7502/pdf/nature13302.pdf M. Kim ''A draft map of the human proteome'' Nature, 2014 509, 575–581]</ref>
 
|<ref name="Kim2014"> [http://www.nature.com/nature/journal/v509/n7502/pdf/nature13302.pdf M. Kim ''A draft map of the human proteome'' Nature, 2014 509, 575–581]</ref>
 
|-
 
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{| class="wikitable"
 
{| class="wikitable"
 
|+  style="text-align: left;" | Description of the 15-LOX concentration distribution
 
|+  style="text-align: left;" | Description of the 15-LOX concentration distribution
! Mode (mM) !! Confidence Interval !! Location parameter (µ) !! Scale parameter (σ)
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! Mode (ppm) !! Mode (mM) !! Confidence Interval !! Location parameter (µ) !! Scale parameter (σ)
 
|-
 
|-
| 4.98E-01 || 7.23E+00 || 7.12E-01 || 1.19E+00
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| 4.07 || 2.25E-05|| 7.23E+00 || 7.12E-01 || 1.19E+00
 
|}
 
|}
  
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! Species
 
! Species
 
! Notes
 
! Notes
 +
! Weight
 
! Reference
 
! Reference
 
|-
 
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pH: 7.3  
 
pH: 7.3  
 
ionic strength: 0.25
 
ionic strength: 0.25
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|64
 
|<ref name="MetaCyc”>[http://metacyc.org/META/NEW-IMAGE?type=REACTION&object=RXN66-490 Caspi et al 2014, "The MetaCyc database of metabolic pathways and enzymes and the BioCyc collection of Pathway/Genome Databases," Nucleic Acids Research 42:D459-D471]</ref>
 
|<ref name="MetaCyc”>[http://metacyc.org/META/NEW-IMAGE?type=REACTION&object=RXN66-490 Caspi et al 2014, "The MetaCyc database of metabolic pathways and enzymes and the BioCyc collection of Pathway/Genome Databases," Nucleic Acids Research 42:D459-D471]</ref>
 
|}
 
|}

Latest revision as of 09:19, 21 August 2019

Return to overview

The genes ALOX15B and ALOX15 encodes the formation of two isoforms of 15-lioxygenase (15-LOX). The gene ALOX15B encodes the formation of 15-LOX-2, which converts AA exclusively into 15(S)-HPETE. Whereas the gene ALOX15 encodes the 15-LOX-1 protein, which converts AA into both 12(S)-HPETE and 15(S)-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

R17 AA - HPETE15.jpg

Chemical equation

 AA \rightleftharpoons 15-HPETE

Rate equation

R17.PNG

15-LOX Parameters

Kms

Literature values
Value Units Species Notes Weight Reference
3.70E-03 ± 3.00E-04  mM Human Expression Vector: Epithelium

Enzyme: 15-Lipoxygenase pH: 7.5 Temperature: 25

512 [1]
5.00E-03  mM Human Expression Vector: Reticulocyte

Enzyme: 15-Lipoxygenase pH:7.5 Temperature: Unspecified

512 [2]
1.06E-02  mM Human Expression Vector: Keratinocyte

Enzyme: 15-Lipoxygenase pH: 6.7 - 7.3 Temperature: 37

2048 [3]
1.17E-02 ± 9.00E-04  mM Human Expression Vector: Baculovirus Insect Cell

Enzyme: Wildtype 15-Lipoxygenase pH: 6.8 Temperature: 37

512 [4]
Description of the 15-LOX Kms distribution
Mode (mM) Confidence Interval Location parameter (µ) Scale parameter (σ)
1.02E-02 2.40E+00 -4.42E+00 4.10E-01
The estimated probability distribution for 15-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 15-LOX Kmp distribution
Mode (mM) Location parameter (µ) Scale parameter (σ)
1.02E-02 -4.42E+00 4.11E-01
The estimated probability distribution for 15-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
595.8 ± 16.8  minute^{-1} Human Expression Vector: Epithelium

Enzyme: 15-Lipoxygenase pH: 7.5 Temperature: 25

512 [1]
37.2 ± 1.8 per minute Expression Vector:Human prostate epithelial

Enzyme:15-lipoxygenase-2

pH 7, Temperature: 22 512 [5]
45 ± 1.2 pH 7.5, Temperature: 22
44.4 ± 2.4 pH 8, Temperature: 22
34.2 ± 0.6 15°C, pH = 7.5
45 ± 1.2 22°C, pH = 7.5
62.4 ± 4.2 30°C, pH = 7.5
82.8 ± 4.8 37°C, pH = 7.5
Description of the 15-LOX kcat distribution
Mode (min-1) Confidence Interval Location parameter (µ) Scale parameter (σ)
6.51E+01 4.62E+00 4.60E+00 6.50E-01
The estimated probability distribution for 15-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
4.09  ppm Human Expression Vector: Lung

Enzyme: 15-LOX pH: 7.5 Temperature: 37 °C

1024 [6]
37.4  ppm Human Expression Vector: Spleen

Enzyme: 15-LOX pH: 7.5 Temperature: 37 °C

1024 [7]
1.40  ppm Human Expression Vector: Gut

Enzyme: 12-LOX pH: 7.5 Temperature: 37 °C

1024 [6]
Description of the 15-LOX concentration distribution
Mode (ppm) Mode (mM) Confidence Interval Location parameter (µ) Scale parameter (σ)
4.07 2.25E-05 7.23E+00 7.12E-01 1.19E+00
The estimated probability distribution for 15-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
(-69.979996) kcal/mol Not stated Estimated

Enzyme: 15-LOX Substrate: Arachidonate Product: 15-HPETE pH: 7.3 ionic strength: 0.25

64 [8]
Description of the 15-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 15-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

Related Reactions