Difference between revisions of "Transformation of TXA2 to TXB2"
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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]] | ||
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+ | Upon generating the unstable metabolite TXA2, it is rapidly hydrolysed into TXB2 via a non-enzymatic reaction under physiological conditions. This inactive metabolite is produced by the incorporation of two hydrogens and one oxygen at C9 and C11, resulting in the opening of the trimethylene oxide ring, and the generation of two hydroxyl groups on the tetrahydropyran ring. | ||
+ | |||
== Reaction == | == Reaction == | ||
[[File:R6_TXA2_-_TXB2.jpg|center|500px]] | [[File:R6_TXA2_-_TXB2.jpg|center|500px]] | ||
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==Chemical equation== | ==Chemical equation== | ||
− | <center><math> | + | <center><math> TXA2 \rightleftharpoons TXB2 </math></center> |
== Rate equation == | == Rate equation == | ||
+ | [[File:R06.PNG|center|500px]] | ||
== Parameters == | == Parameters == | ||
+ | === Association Rate Constant (Kf) === | ||
{|class="wikitable sortable" | {|class="wikitable sortable" | ||
− | |+ style="text-align: left;" | | + | |+ style="text-align: left;" | Literature values |
|- | |- | ||
! Value | ! Value | ||
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! Conditions | ! Conditions | ||
! Substrate | ! Substrate | ||
+ | ! Weight | ||
! Reference | ! Reference | ||
|- | |- | ||
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Temperature: 25°C | Temperature: 25°C | ||
|3 | |3 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
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Temperature: 25°C | Temperature: 25°C | ||
|3 | |3 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
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Temperature: 25°C | Temperature: 25°C | ||
|4 | |4 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
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Temperature: 25°C | Temperature: 25°C | ||
|4 | |4 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
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Temperature: 25°C | Temperature: 25°C | ||
|5 | |5 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
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Temperature: 25°C | Temperature: 25°C | ||
|6 | |6 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
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Temperature: 25°C | Temperature: 25°C | ||
|7 | |7 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
Line 75: | Line 88: | ||
Temperature: 25°C | Temperature: 25°C | ||
|8 | |8 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
Line 82: | Line 96: | ||
Temperature: 25°C | Temperature: 25°C | ||
|8 | |8 | ||
+ | |32 | ||
|<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | |<ref name="Ross1982”>[http://pubs.acs.org/doi/pdf/10.1021/ja00370a035 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665]</ref> | ||
|- | |- | ||
+ | | 2.25 ± 0.12 | ||
+ | | M-1 min-1 | ||
+ | | 25°C, in imidazole buffer and also in phosphate buffers, | ||
+ | | CO2 to H2CO3 | ||
+ | |32 | ||
+ | | <ref name="Gibbons1963”>[http://www.jbc.org/content/238/10/3502.full.pdf B. Gibbons "Rate of Hydration of Carbon Dioxide and Dehydration of Carbonic Acid at 25" J Biol Chem. 1963 Oct;238:3502-7]</ref> | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | {| class="wikitable" | ||
+ | |+ style="text-align: left;" | Description of the reaction 6 Kf distribution | ||
+ | ! Mode (M-1 s-1) !! Confidence Interval !! Location parameter (µ) !! Scale parameter (σ) | ||
+ | |- | ||
+ | | 3.70E+03 || 3.44E+01 || 1.10E+01 || 1.66E+00 | ||
+ | |} | ||
+ | |||
+ | [[Image:21.jpg|none|thumb|500px|The estimated probability distribution for reaction 6 Kf. 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. ]] | ||
+ | |||
+ | === Dissociation Rate Constant (Kr) === | ||
+ | This is a “Dependent parameter”, meaning that the log-normal distribution for this parameter was calculated using multivariate distributions (this is discussed in detail[[Quantification of parameter uncertainty | here]]). As a result, no confidence interval factor or literature values were cited for this parameter. | ||
+ | |||
+ | {| class="wikitable" | ||
+ | |+ style="text-align: left;" | Description of the reaction 6 Kr distribution | ||
+ | ! Mode !! Location parameter (µ) !! Scale parameter (σ) | ||
+ | |- | ||
+ | | 5.28E+01 || 5.63E+00 || 1.29E+00 | ||
+ | |} | ||
+ | |||
+ | [[Image:22.jpg|none|thumb|500px|The estimated probability distribution for reaction 6 Kr. 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. ]] | ||
+ | |||
+ | === Dissociation Constant === | ||
+ | {|class="wikitable sortable" | ||
+ | |+ style="text-align: left;" | Literature values | ||
+ | |- | ||
+ | ! Value | ||
+ | ! Units | ||
+ | ! Conditions | ||
+ | ! Substrate | ||
+ | ! Weight | ||
+ | ! Reference | ||
+ | |- | ||
+ | |0.000038 | ||
+ | |mM | ||
+ | |Temperature: 35°C | ||
+ | Vector:Mosquito | ||
+ | Note: "In solution, it undergoes rapid hydrolysis to form TXB2, a stable but physiologically inactive compound." - therefore they used stable analogues. | ||
+ | |carbocyclic TXA2 (analogue of TXA2) | ||
+ | |24 | ||
+ | |<ref name="Alvarenga2010”>[http://journals.plos.org/plosbiology/article/file?id=10.1371/journal.pbio.1000547&type=printable P. H. Alvarenga "The Function and Three-Dimensional Structure of a Thromboxane A2/Cysteinyl Leukotriene-Binding Protein from the Saliva of a Mosquito Vector of the Malaria Parasite" PLoS Biol. 2010 Nov 30;8(11):e1000547. doi: 10.1371/journal.pbio.1000547.]</ref> | ||
+ | |- | ||
+ | |0.00000023 | ||
+ | |mM | ||
+ | |Temperature: 35°C | ||
+ | Vector:Rabbit cultured astrocytes | ||
+ | |||
+ | Note: "In solution, it undergoes rapid hydrolysis to form TXB2, a stable but physiologically inactive compound." - therefore they used stable analogues. | ||
+ | |[3H]IONO NT-126, a TXA z antagonist, | ||
+ | |36 | ||
+ | |<ref name="Nakahata1992”>[http://ac.els-cdn.com/S0006899310800137/1-s2.0-S0006899310800137-main.pdf?_tid=b2ab095e-155f-11e7-94f0-00000aab0f26&acdnat=1490888822_58d1d45dc3238dede94e4a2f15cada82 N Nakahata et al. "The Presence of Thromboxane A2 Receptors in Cultured Astrocytes From Rabbit Brain" Brain Res 583 (1-2), 100-104. 1992 Jun 26]</ref> | ||
+ | |- | ||
+ | |1500 ± 500 (excluded) | ||
+ | |mM | ||
+ | |Temperature: 25°C | ||
+ | In vitro | ||
+ | |Hydroxysulfamic acid | ||
+ | [[File:HSA.PNG |center|500px]] | ||
+ | |16 | ||
+ | |<ref name="Littlejohn1989”>[http://www.nrcresearchpress.com/doi/pdf/10.1139/v89-243 D. LITTLEJOHN "The dissociation constant and acid hydrolysis rate of hydroxysulfamic acid" Can. J. Chem. 67, 1596 (1989).]</ref> | ||
+ | |- | ||
+ | |[[File:H202.PNG |center|500px]] | ||
+ | |N/A | ||
+ | |Temperature: 20°C | ||
+ | In vitro | ||
+ | |H2O2 | ||
+ | |16 | ||
+ | |<ref name="Evan1949”>[http://pubs.rsc.org/-/content/articlepdf/1949/tf/tf9494500224 M. G. EVAN "The dissociation constant and acid hydrolysis rate of hydroxysulfamic acid" Trans. Faraday Soc., 1949,45, 224-230]</ref> | ||
+ | |- | ||
+ | |5.9 E-8 | ||
+ | |N/A | ||
+ | |Oxaliplatin | ||
+ | |[[File:Oxaliplatin.PNG |center|500px]] | ||
+ | |16 | ||
+ | |<ref name="Jerremalm”>[http://www.sciencedirect.com/science/article/pii/S0022354916311649 Elin Jerremalm "Hydrolysis of Oxaliplatin—Evaluation of the Acid Dissociation Constant for the Oxalato Monodentate Complex" Journal of Pharmaceutical Sciences Volume 92, Issue 2, February 2003, Pages 436–438]</ref> | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | {| class="wikitable" | ||
+ | |+ style="text-align: left;" | Description of the reaction 6 KD distribution | ||
+ | ! Mode (M-1 s-1) !! Confidence Interval !! Location parameter (µ) !! Scale parameter (σ) | ||
+ | |- | ||
+ | | 2.35E-07 || 1.76E+04 || -6.86E+00 || 2.90E+00 | ||
|} | |} | ||
+ | |||
+ | [[Image:R6 KD.jpg|none|thumb|500px|The estimated probability distribution for reaction 6 Kr. 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. ]] | ||
== Related Reactions == | == Related Reactions == |
Latest revision as of 11:07, 2 November 2019
Upon generating the unstable metabolite TXA2, it is rapidly hydrolysed into TXB2 via a non-enzymatic reaction under physiological conditions. This inactive metabolite is produced by the incorporation of two hydrogens and one oxygen at C9 and C11, resulting in the opening of the trimethylene oxide ring, and the generation of two hydroxyl groups on the tetrahydropyran ring.
Contents
Reaction
Chemical equation
Rate equation
Parameters
Association Rate Constant (Kf)
Value | Units | Conditions | Substrate | Weight | Reference |
---|---|---|---|---|---|
3.7e3 ± 0.1e3 | M-1 s-1 | NaCl04 (0.1 - 0.2 M)
Temperature: 25°C |
3 | 32 | [1] |
8.7e3 | M-1 s-1 | KCl (1 M)
Temperature: 25°C |
3 | 32 | [1] |
1.1e4 ± 0.1e4 | M-1 s-1 | NaCl04 (0.1 - 0.2 M)
Temperature: 25°C |
4 | 32 | [1] |
2.4 e4 | M-1 s-1 | KCl (1M)
Temperature: 25°C |
4 | 32 | [1] |
3.7e3 ± 0.1e3 | M-1 s-1 | NaCl04 (0.1 - 0.2 M)
Temperature: 25°C |
5 | 32 | [1] |
3.6 ± 0.2 | M-1 s-1 | NaCl04 (0.1 - 0.2 M)
Temperature: 25°C |
6 | 32 | [1] |
1.7 ± 0.1 | M-1 s-1 | NaCl04 (0.1 - 0.2 M)
Temperature: 25°C |
7 | 32 | [1] |
26.7 ± 0.9 | M-1 s-1 | NaCl04 (0.1 - 0.2 M)
Temperature: 25°C |
8 | 32 | [1] |
35 | M-1 s-1 | KCl (1M)
Temperature: 25°C |
8 | 32 | [1] |
2.25 ± 0.12 | M-1 min-1 | 25°C, in imidazole buffer and also in phosphate buffers, | CO2 to H2CO3 | 32 | [2] |
Mode (M-1 s-1) | Confidence Interval | Location parameter (µ) | Scale parameter (σ) |
---|---|---|---|
3.70E+03 | 3.44E+01 | 1.10E+01 | 1.66E+00 |
Dissociation Rate Constant (Kr)
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.
Mode | Location parameter (µ) | Scale parameter (σ) |
---|---|---|
5.28E+01 | 5.63E+00 | 1.29E+00 |
Dissociation Constant
Value | Units | Conditions | Substrate | Weight | Reference |
---|---|---|---|---|---|
0.000038 | mM | Temperature: 35°C
Vector:Mosquito Note: "In solution, it undergoes rapid hydrolysis to form TXB2, a stable but physiologically inactive compound." - therefore they used stable analogues. |
carbocyclic TXA2 (analogue of TXA2) | 24 | [3] |
0.00000023 | mM | Temperature: 35°C
Vector:Rabbit cultured astrocytes Note: "In solution, it undergoes rapid hydrolysis to form TXB2, a stable but physiologically inactive compound." - therefore they used stable analogues. |
[3H]IONO NT-126, a TXA z antagonist, | 36 | [4] |
1500 ± 500 (excluded) | mM | Temperature: 25°C
In vitro |
Hydroxysulfamic acid | 16 | [5] |
N/A | Temperature: 20°C
In vitro |
H2O2 | 16 | [6] | |
5.9 E-8 | N/A | Oxaliplatin | 16 | [7] |
Mode (M-1 s-1) | Confidence Interval | Location parameter (µ) | Scale parameter (σ) |
---|---|---|---|
2.35E-07 | 1.76E+04 | -6.86E+00 | 2.90E+00 |
Related Reactions
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 A. Ross "Vinyl epoxide hydrolysis reactions" J. Am. Chem. Soc., 1982, 104 (6), pp 1658–1665
- ↑ B. Gibbons "Rate of Hydration of Carbon Dioxide and Dehydration of Carbonic Acid at 25" J Biol Chem. 1963 Oct;238:3502-7
- ↑ P. H. Alvarenga "The Function and Three-Dimensional Structure of a Thromboxane A2/Cysteinyl Leukotriene-Binding Protein from the Saliva of a Mosquito Vector of the Malaria Parasite" PLoS Biol. 2010 Nov 30;8(11):e1000547. doi: 10.1371/journal.pbio.1000547.
- ↑ N Nakahata et al. "The Presence of Thromboxane A2 Receptors in Cultured Astrocytes From Rabbit Brain" Brain Res 583 (1-2), 100-104. 1992 Jun 26
- ↑ D. LITTLEJOHN "The dissociation constant and acid hydrolysis rate of hydroxysulfamic acid" Can. J. Chem. 67, 1596 (1989).
- ↑ M. G. EVAN "The dissociation constant and acid hydrolysis rate of hydroxysulfamic acid" Trans. Faraday Soc., 1949,45, 224-230
- ↑ Elin Jerremalm "Hydrolysis of Oxaliplatin—Evaluation of the Acid Dissociation Constant for the Oxalato Monodentate Complex" Journal of Pharmaceutical Sciences Volume 92, Issue 2, February 2003, Pages 436–438