Transformation of PGE2 to 15-Keto-PGE2

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The primary catabolic pathway of prostanoids is initiated by the oxidation of the C15 hydroxyl group by 15-prostoglandin dehydrogenase (15-PGDH). 15-PGDH can accept a wide variety of prostaglandins as substrates. Two isoforms of 15-PGDH have been recognised, Type I is NAD+ specific, whereas Type II prefers NADP+. 15-PGDH Type I is prostaglandin and lipoxin specific, whereas Type II exhibits broad substrate specificity, therefore Type I is typically referred to as 15-PGDH in the literature [1][2].

Reaction

R66 15PGDH.jpg

Chemical equation

PGE2 \rightleftharpoons 15-Keto-PGE2

Rate equation

R66.PNG

Enzyme Parameters

Kms

Literature values
Value Units Species Notes Weight Reference
0.008 mM Rat Skin Method:

pH:7.4 Temperature: 37'C Substrate: PGE2 + NAD+

1024 [3]
0.0075 mM Rat Skin Method:

pH:7.4 Temperature: 37'C Substrate: PGE2 + NADP+

1024 [3]
0.024 mM Rat Skin Method:

pH:7.4 Temperature: 37'C Substrate: PGF2a + NAD+

1024 [3]
0.023 mM Rat Skin Method:

pH:7.4 Temperature: 37'C Substrate: PGF2a + NADP+

1024 [3]
0.0039 mM Purified Human 15-PGDH Method: In vitro

Expression Vector: E. coli pH:7.5 Temperature: 37'C Substrate: PGE2

1024 [4]
0.0099 mM Purified Rat 15-PGDH Method: In vitro

Expression Vector: E. coli pH:7.5 Temperature: 37'C Substrate: PGE2

512 [4]
0.0055 ± 0.0006 mM Human Method:In vitro

Expression Vector: E. Coli pH:8 Temperature: 25 Substrate: PGE2 + NAD+

1024 [5]
Description of the 15-PGDH Kms distribution
Mode (mM) Confidence Interval Location parameter (μ) Scale parameter (σ)
7.64E-03 5.05E+00 -4.41E+00 6.80E-01
The estimated probability distribution for 15-PGDH 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-PGDH Kmp distribution
Mode (mM) Location parameter (μ) Scale parameter (σ)
7.70E-03 -4.41E+00 6.72E-01
The estimated probability distribution for 15-PGDH 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
816 ± 18 per minute Human Method: In vitro

Expression Vector: E. Coli pH:8 Temperature: 25 Substrate: PGE2 + NAD+

128 [5]
366 ± 12 - 846 ± 12 per minute Human Method: In vitro

Expression Vector: E. Coli pH:8 Temperature: 25 Substrate: PGE2 + NAD+ + Inhibitor

128 [5]
Description of the 15-PGDH kcat distribution
Mode (min-1) Confidence Interval Location parameter (μ) Scale parameter (σ)
8.12E+02 5.38E+00 7.19E+00 7.01E-01
The estimated probability distribution for 15-PGDH 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
69.8 ppm Human Expression Vector: Esophagus

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

1024 [6]
22.1 ppm Human Expression Vector: Heart

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

1024 [7]
11.2 ppm Human Expression Vector: Esophagus

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

1024 [7]
7.68 ppm Human Expression Vector: Skin

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

2048 Paxdb - Unknown
Description of the 15-PGDH concentration distribution
Mode (ppm) Mode (mM) Confidence Interval Location parameter (μ) Scale parameter (σ)
1.12E+01 6.20E-05 2.32E+00 2.87E+00 6.80E-01
The estimated probability distribution for 15-PGDH 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

Gibbs Free Energy Change
Value Units Species Notes Weight Reference
(-0.46818542) kcal/mol Calculated Estimated

Enzyme: 15-PGDH Substrate: PGE2 Product: 15-dehydro-PGE2 pH: 7.3 ionic strength: 0.25

64 [8]
Description of the 15-PGDH Keq distribution
Mode Confidence Interval Location parameter (μ) Scale parameter (σ)
2.21E+00 1.00E+01 1.58E+00 8.91E-01
The estimated probability distribution for 15-PGDH 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

  1. ↑ Ensor, C. M. Tai, H. H., 15-Hydroxyprostaglandin dehydrogenase, J Lipid Mediat Cell Signal (1995), 12, 313-9.
  2. ↑ Wermuth, B., Purification and properties of an NADPH-dependent carbonyl reductase from human brain. Relationship to prostaglandin 9-ketoreductase and xenobiotic ketone reductase, J Biol Chem (1981), 256, 1206-13.
  3. ↑ 3.0 3.1 3.2 3.3 N. Fincham, Novel prostaglandin dehydrogenase in rat skin. Biochem J. 1983 Apr 15;212(1):129-34.
  4. ↑ 4.0 4.1 Zhou H., C-Terminal region of human NAD+-dependent 15-hydroxyprostaglandin dehydrogenase is involved in the interaction with prostaglandin substrates. Eur J Biochem. 2001 Jun;268(12):3368-74.
  5. ↑ 5.0 5.1 5.2 F. Niesen,, High-Affinity Inhibitors of Human NAD+-Dependent 15-Hydroxyprostaglandin Dehydrogenase: Mechanisms of Inhibition and Structure-Activity Relationships PLoS One. 2010 Nov 2;5(11):e13719.
  6. ↑ M. Wilhelm Mass-spectrometry-based draft of the human proteome Nature, 2014 509, 582–587
  7. ↑ 7.0 7.1 M. Kim A draft map of the human proteome Nature, 2014 509, 575–581
  8. ↑ 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
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