biology

NADPH—hemoprotein reductase

NADPH—hemoprotein reductase is a biology 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 NADPH—hemoprotein reductase rather than just read about it. In short: In enzymology, a NADPH—hemoprotein reductase is an enzyme that catalyzes the chemical reaction NADPH + H+ + n oxidized hemoprotein ⇌ {\displaystyle \rightleftharpoons } NADP+ + n reduced hemoprotein The three substrates of this enzyme are NADPH, H+, and oxidized hemoprotein, whereas its two products are NADP+ and reduced hemoprotein. It has two cofactors: flavin adenine dinucleotide (FAD) and flavin mononucleotide (…

Key takeaways

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

Reference excerpt

In enzymology, a NADPH—hemoprotein reductase is an enzyme that catalyzes the chemical reaction

NADPH + H+ + n oxidized hemoprotein ⇌ {\displaystyle \rightleftharpoons } NADP+ + n reduced hemoprotein The three substrates of this enzyme are NADPH, H+, and oxidized hemoprotein, whereas its two products are NADP+ and reduced hemoprotein. It has two cofactors: flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). This enzyme belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with a heme protein as acceptor. The systematic name of this enzyme class is NADPH:hemoprotein oxidoreductase. Other names include cytochrome P450 reductase, ferrihemoprotein P-450 reductase, and NADPH-dependent cytochrome c reductase.

Structural studies As of late 2007, 10 structures have been solved for this class of enzymes, with PDB accession codes PDB: 1AMO, PDB: 1B1C, PDB: 1J9Z, PDB: 1JA0, PDB: 1JA1, PDB: 1YQO, PDB: 1YQP, PDB: 2BF4, PDB: 2BN4, and PDB: 2BPO.

References

Haas E, Horecker BL, Hogness TR (1940). "The enzymatic reduction of cytochrome c, cytochrome c reductase". J. Biol. Chem. 136: 747–774. doi:10.1016/S0021-9258(18)73034-2. Horecker BL (1950). "Triphosphopyridine nucleotide-cytochrome c reductase in liver". J. Biol. Chem. 183 (2): 593–605. doi:10.1016/S0021-9258(19)51185-1. Lu AY, Junk KW, Coon MJ (1969). "Resolution of the cytochrome P-450-containing omega-hydroxylation system of liver microsomes into three components". J. Biol. Chem. 244 (13): 3714–21. doi:10.1016/S0021-9258(18)83427-5. PMID 4389465. GIBSON QH, PALMER G, WHARTON DC (1965). "Studies on the Mechanism of Microsomal Triphosphopyridine Nucleotide-Cytochrome C Reductase". J. Biol. Chem. 240 (2): 921–31. doi:10.1016/S0021-9258(17)45262-8. PMID 14275154. WILLIAMS CH Jr; KAMIN H (1962). "Microsomal triphosphopyridine nucleotide-cytochrome c reductase of liver". J. Biol. Chem. 237 (2): 587–95. doi:10.1016/S0021-9258(18)93967-0. PMID 14007123. Masters BS, Bilimoria MH, Kamin H, Gibson QH (1965). "The mechanism of 1- and 2-electron transfers catalyzed by reduced triphosphopyridine nucleotide-cytochrome c reductase". J. Biol. Chem. 240 (10): 4081–8. doi:10.1016/S0021-9258(18)97152-8. PMID 4378860. Sevrioukova IF, Peterson JA (1995). "NADPH-P-450 reductase: structural and functional comparisons of the eukaryotic and prokaryotic isoforms". Biochimie. 77 (7–8): 562–72. doi:10.1016/0300-9084(96)88172-7. PMID 8589067. Wang M, Roberts DL, Paschke R, Shea TM, Masters BS, Kim JJ (1997). "Three-dimensional structure of NADPH-cytochrome P450 reductase: prototype for FMN- and FAD-containing enzymes". Proc. Natl. Acad. Sci. U.S.A. 94 (16): 8411–6. Bibcode:1997PNAS...94.8411W. doi:10.1073/pnas.94.16.8411. PMC 22938. PMID 9237990. Munro AW, Noble MA, Robledo L, Daff SN, Chapman SK (2001). "Determination of the redox properties of human NADPH-cytochrome P450 reductase". Biochemistry. 40 (7): 1956–63. doi:10.1021/bi001718u. PMID 11329262. Munro AW, Noble MA, Robledo L, Daff SN, Chapman SK (2001). "Determination of the redox properties of human NADPH-cytochrome P450 reductase". Biochemistry. 40 (7): 1956–63. doi:10.1021/bi001718u. PMID 11329262. Scrutton NS; Grunau, A; Paine, M; Munro, AW; Wolf, CR; Roberts, GC; Scrutton, NS (2003). "Electron transfer in human cytochrome P450 reductase". Biochem. Soc. Trans. 31 (Pt 3): 497–501. doi:10.1042/BST0310497. hdl:2381/11955. PMID 12773143. Scrutton NS; Grunau, A; Paine, M; Munro, AW; Wolf, CR; Roberts, GC; Scrutton, NS (2003). "Electron transfer in human cytochrome P450 reductase". Biochem. Soc. Trans. 31 (Pt 3): 497–501. doi:10.1042/BST0310497. hdl:2381/11955. PMID 12773143.

Illustrations

Worked examples

Example 1 — a first encounter with NADPH—hemoprotein reductase

Start with the simplest possible case. Write down what NADPH—hemoprotein reductase claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 NADPH—hemoprotein reductase 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 NADPH—hemoprotein reductase 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 NADPH—hemoprotein reductase

In research: NADPH—hemoprotein reductase appears in biology 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 NADPH—hemoprotein reductase 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: NADPH—hemoprotein reductase is common in secondary-school and first-year university syllabi. It links to neighbouring topics EC 1.6.2, Enzymes of known structure, Flavoproteins, so understanding it makes those chapters shorter.
In everyday life: Look for NADPH—hemoprotein reductase 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 NADPH—hemoprotein reductase in 20 minutes

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Frequently asked questions

What is NADPH—hemoprotein reductase in simple terms?

In enzymology, a NADPH—hemoprotein reductase is an enzyme that catalyzes the chemical reaction NADPH + H+ + n oxidized hemoprotein ⇌ {\displaystyle \rightleftharpoons } NADP+ + n reduced hemoprotein The three substrates of this enzyme are NADPH, H+, and oxidized hemoprotein, whereas its two product…

Why does NADPH—hemoprotein reductase matter?

Because it connects several biology 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 NADPH—hemoprotein reductase?

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 NADPH—hemoprotein reductase.