engineering

Pyruvate synthase

Pyruvate synthase is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Pyruvate synthase rather than just read about it. In short: In enzymology, pyruvate synthase (EC 1.2.7.1) is an enzyme that catalyzes the interconversion of pyruvate and acetyl-CoA. It is also called pyruvate:ferredoxin oxidoreductase (PFOR).

Key takeaways

Pyruvate synthase belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pyruvate synthase to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pyruvate synthase from memory before moving on to harder problems.

Reference excerpt

In enzymology, pyruvate synthase (EC 1.2.7.1) is an enzyme that catalyzes the interconversion of pyruvate and acetyl-CoA. It is also called pyruvate:ferredoxin oxidoreductase (PFOR). When the equilibrium favours the synthesis of pyruvic acid the reaction is:

The substrates are acetyl-CoA, carbon dioxide, two protons, and reduced ferredoxin. The products are then pyruvic acid, coenzyme A, and oxidized ferredoxin.

Function This enzyme participates in four metabolic pathways: pyruvate metabolism, propanoate metabolism, butanoate metabolism, and reductive carboxylate cycle (CO2 fixation). Its major role is the extraction of reducing equivalents by the decarboxylation. In aerobic organisms, this conversion is catalysed by pyruvate dehydrogenase, which also uses thiamine pyrophosphate (TPP) but relies on lipoate as the electron acceptor. Unlike the aerobic enzyme complex PFOR transfers reducing equivalents to flavins or iron-sulfur clusters. This process links glycolysis to the Wood–Ljungdahl pathway.

Nomenclature This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with an iron-sulfur protein as acceptor. The systematic name of this enzyme class is pyruvate:ferredoxin 2-oxidoreductase (CoA-acetylating). Other names in common use include:

pyruvate oxidoreductase, pyruvate synthetase, pyruvate:ferredoxin oxidoreductase, pyruvic-ferredoxin oxidoreductase.

Structure PFOR adopts a dimeric structure, while each monomeric subunit is composed of one or multiple chain(s) of polypeptides. Each monomeric subunit of PFOR consists of six domains binding one TPP molecule and three [4Fe-4S] clusters.

Catalytic mechanism An PFOR reaction starts with the nucleophilic attack of C2 of TPP on the 2-oxo carbon of pyruvate, which forms a lactyl-TPP adduct. Next, the lactyl-TPP adduct releases the CO2 moiety, forming an anionic intermediate, which then transfer an electron to a [4Fe-4S] cluster. These steps lead to a stable radical intermediate that can be observed by electron paramagnetic resonance (EPR) experiments. The radical intermediate reacts with a CoA molecule, transfers another electron from the radical intermediate to a [4Fe-4S] cluster and forms an acetyl-CoA product.

Related medications

Inhibitors Nitazoxanide is a broad-spectrum antiparasitic drug and FDA-approved PFOR inhibitor which is used for the treatment of Giardiasis and Cryptosporidiosis. Tizoxanide, an active metabolite of nitazoxanide Amixicile, a water-soluble derivative of nitazoxanide, is a potent inhibitor of pyruvate:ferredoxin oxidoreductase and is in pre-clinical studies to treat infections of Helicobacter pylori and Clostridioides difficile.

Others Metronidazole, a wide-spectrum antibiotic that targets anaerobic organisms, receive electron from the reduced ferredoxin produced by PFOR, thus turning into highly reactive nitrous free radical that destroy DNA and other vital biomolecules.

References

Illustrations

Worked examples

Example 1 — a first encounter with Pyruvate synthase

Start with the simplest possible case. Write down what Pyruvate synthase claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pyruvate synthase before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pyruvate synthase ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pyruvate synthase

In research: Pyruvate synthase appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pyruvate synthase in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pyruvate synthase is common in secondary-school and first-year university syllabi. It links to neighbouring topics EC 1.2.7, EC 1.2 stubs, Enzymes of known structure, so understanding it makes those chapters shorter.
In everyday life: Look for Pyruvate synthase outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Pyruvate synthase in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pyruvate synthase means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pyruvate synthase out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pyruvate synthase in simple terms?

In enzymology, pyruvate synthase (EC 1.2.7.1) is an enzyme that catalyzes the interconversion of pyruvate and acetyl-CoA. It is also called pyruvate:ferredoxin oxidoreductase (PFOR).

Why does Pyruvate synthase matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pyruvate synthase?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pyruvate synthase.