Difference between revisions of "Malate"
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'''M: Malate''' (L-Malic acid, C<sub>4</sub>H<sub>6</sub>0<sub>5</sub>); Sigma M 1000, 100 g, store at RT; FW = 134.1. | '''M: Malate''' (L-Malic acid, C<sub>4</sub>H<sub>6</sub>0<sub>5</sub>); Sigma M 1000, 100 g, store at RT; FW = 134.1. | ||
'''Preparation of | '''Preparation of 400 mM stock solution''' (dissolved in H<sub>2</sub>O): | ||
::1) Weigh | ::1) Weigh 268.2 mg of L-malic acid. | ||
::2) Add 3 mL H<sub>2</sub>O. | ::2) Add 3 mL H<sub>2</sub>O. | ||
::3) Neutralize with 5 M KOH (approx. 350 µL). | ::3) Neutralize with 5 M KOH (approx. 350 µL). | ||
| Line 27: | Line 27: | ||
::5) Divide into 0.5 mL portions. | ::5) Divide into 0.5 mL portions. | ||
::6) Store frozen at -20 °C. | ::6) Store frozen at -20 °C. | ||
'''O2k manual titrations''' >> [[MiPNet09.12 O2k-Titrations]] | '''O2k manual titrations''' >> [[MiPNet09.12 O2k-Titrations]] | ||
::* Titration volume: | ::* Titration volume: 10 µL 400 mM using a 25 µL Hamilton syringe (2 mL O2k-Chamber). | ||
::* Final concenteration: 2.0 mM | ::* Final concenteration: 2.0 mM. | ||
[[Image:BB-Bioblast.jpg|left|30px|link=Bioblast:About|Bioblast wiki]] | [[Image:BB-Bioblast.jpg|left|30px|link=Bioblast:About|Bioblast wiki]] | ||
| Line 39: | Line 37: | ||
In mitochondrial preparations obtained from a diversity of tissues and organisms malate at concentrations >0.5 mM exerted an inhibitory effect on succinate-pathway (S-pathway) and NADH and S (NS-)pathway, whereas 0.5 mM malate was saturating for NADH (N-) linked respiration. Selection of an optimum malate concentration for SUIT protocols is a compromise. Current investigations point towards 2 mM malate. [http://www.bioblast.at/index.php/Sumbalova_2016a_Abstract_MitoFit_Science_Camp_2016 Sumbalova_2016a_Abstract_MitoFit_Science_Camp_2016] | In mitochondrial preparations obtained from a diversity of tissues and organisms malate at concentrations >0.5 mM exerted an inhibitory effect on succinate-pathway (S-pathway) and NADH and S (NS-)pathway, whereas 0.5 mM malate was saturating for NADH (N-) linked respiration. Selection of an optimum malate concentration for SUIT protocols is a compromise. Current investigations point towards 2 mM malate. [http://www.bioblast.at/index.php/Sumbalova_2016a_Abstract_MitoFit_Science_Camp_2016 Sumbalova_2016a_Abstract_MitoFit_Science_Camp_2016] | ||
Comment: 800 mM stock until 2013-11-20 (for 2 mM final concentration); 400 mM stock (for 0.5 mM final concentration) in discussion since then. | |||
* ''Further details'': »[[Talk:Malate|Discussion]]. | * ''Further details'': »[[Talk:Malate|Discussion]]. | ||
Revision as of 11:55, 11 March 2019
- high-resolution terminology - matching measurements at high-resolution
Malate
Description
Malic acid, C4H6O5, occurs under physiological conditions as the anion malate2-, M, with pKa1 = 3.40 and pKa2 = 5.20. L-Malate is formed from fumarate in the TCA cycle in the mitochondrial matrix, where it is the substrate of malate dehydrogenase oxidized to oxaloacetate. Malate is also formed in the cytosol. It cannot permeate through the lipid bilayer of membranes and hence requires a carrier (dicarboxylate carrier, tricarboxylate carrier and 2-oxoglutarate carrier). Malate alone cannot support respiration of mt-preparations from most tissues, since oxaloacetate accumulates in the absence of pyruvate or glutamate.
Abbreviation: M
Reference: Gnaiger 2014 MitoPathways
MitoPedia topics: Substrate and metabolite
Application in HRFR
M: Malate (L-Malic acid, C4H605); Sigma M 1000, 100 g, store at RT; FW = 134.1.
Preparation of 400 mM stock solution (dissolved in H2O):
- 1) Weigh 268.2 mg of L-malic acid.
- 2) Add 3 mL H2O.
- 3) Neutralize with 5 M KOH (approx. 350 µL).
- 4) Adjust final volume to 5 mL (in 5 mL volumetric glass flask).
- 5) Divide into 0.5 mL portions.
- 6) Store frozen at -20 °C.
O2k manual titrations >> MiPNet09.12 O2k-Titrations
- Titration volume: 10 µL 400 mM using a 25 µL Hamilton syringe (2 mL O2k-Chamber).
- Final concenteration: 2.0 mM.
Malate: 0.5 mM versus 2 mM in HRFR
In mitochondrial preparations obtained from a diversity of tissues and organisms malate at concentrations >0.5 mM exerted an inhibitory effect on succinate-pathway (S-pathway) and NADH and S (NS-)pathway, whereas 0.5 mM malate was saturating for NADH (N-) linked respiration. Selection of an optimum malate concentration for SUIT protocols is a compromise. Current investigations point towards 2 mM malate. Sumbalova_2016a_Abstract_MitoFit_Science_Camp_2016
Comment: 800 mM stock until 2013-11-20 (for 2 mM final concentration); 400 mM stock (for 0.5 mM final concentration) in discussion since then.
- Further details: »Discussion.
