Pyruvate Malate Substrates
Pyruvate Malate Substrates - Related Videos
02:29
Pyruvate Assay for Estimation of Pyruvate Levels in Cellular Fractions of Worms
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2025
This video describes a colorimetric assay for quantitatively measuring pyruvate in the cellular fractions of Caenorhabditis elegans. Utilizing the hydrogen peroxide produced from the enzymatic reaction of pyruvate oxidase with cellular pyruvate, a chromogenic dye is oxidized to produce a colored product, measured using colorimetry to determine the pyruvate concentration.
01:15
Pyruvate Oxidation
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2019
After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells. First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
01:20
Fates of Pyruvate
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2025
Pyruvate is the end product of glycolysis, where glucose is oxidized to pyruvate, simultaneously reducing NAD+ to NADH. Two molecules of ATP are also produced by substrate-level phosphorylation. In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
11:13
Identification of Kinase-substrate Pairs Using High Throughput Screening
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Cited by 1 •
2015
Protein phosphorylation is a central feature of how cells interpret and respond to information in their extracellular milieu. Here, we present a high throughput screening protocol using kinases purified from mammalian cells to rapidly identify kinases that phosphorylate a substrate(s) of interest.
03:13
Mitochondrial Calcium Uptake Assay: A Plate Reader-Based Method for Measuring Calcium Uptake in Isolated Mitochondria
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2025
This video describes a plate reader-based assay to measure mitochondrial calcium uptake in isolated mitochondria. The assay analyzes the fluorescence signal of a calcium-sensitive fluorescent dye to study the kinetics of mitochondrial calcium uptake and calcium overload.
FAQs
Together, the substrates support both entry of carbon into mitochondrial metabolism and continued production of reducing equivalents. Pyruvate supplies acetyl-CoA through pyruvate dehydrogenase, producing NADH, while malate supports tricarboxylic acid cycle activity and provides intermediates that help sustain further reducing-equivalent generation. Their combination creates a defined fuel condition for examining respiration rather than relying on an unspecified cellular nutrient mixture.
Because the substrate pair generates NADH, electrons enter the respiratory chain through Complex I. Oxygen consumption measured under this condition therefore reflects respiratory activity supported by that route of electron delivery, together with the downstream oxidative phosphorylation system. A change in oxygen use can consequently indicate altered mitochondrial respiratory function when comparisons are made under the same defined substrate conditions.
Adding ADP or another metabolic effector changes the defined test condition so mitochondrial oxygen consumption can be examined in a particular energetic state. This is useful because the same pyruvate-malate fuel supply can be evaluated with or without an effector, allowing investigators to compare how respiration responds to altered metabolic demand or regulatory input rather than measuring substrate-supported activity in isolation.
In a typical biological-technique setup, investigators expose isolated mitochondria or permeabilized cells to the paired substrates under defined assay conditions and monitor oxygen consumption. ADP or another metabolic effector may be included to test a specific respiratory response. Keeping the preparation and fuel condition controlled makes the resulting oxygen-use measurement suitable for comparing mitochondrial function across samples.
A difference in oxygen consumption under pyruvate-malate-supported conditions may reveal altered mitochondrial respiration or oxidative phosphorylation. Because the assay supplies a defined route involving pyruvate dehydrogenase, the tricarboxylic acid cycle, and Complex I, comparisons can help identify respiratory defects or distinguish how samples respond to the same metabolic challenge. Interpretation depends on comparing equivalent assay conditions.
They provide a controlled metabolic background for examining intervention-related changes in mitochondrial performance. Researchers can compare oxygen consumption among samples exposed to a metabolic or pharmacological intervention while keeping the respiratory fuel pair defined. The resulting comparison helps determine whether the intervention changes respiration supported by pyruvate-derived NADH and associated mitochondrial oxidative phosphorylation.