GO:0004458 D-lactate dehydrogenase (cytochrome) activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004458 describes the molecular function of D-lactate dehydrogenase (cytochrome), which catalyzes the oxidation of (R)-lactate to pyruvate while reducing two molecules of ferricytochrome c to ferrocytochrome c.
• The enzyme is a mitochondrial protein in yeast, encoded by DLD1 in Saccharomyces cerevisiae, and is a flavin-dependent dehydrogenase that feeds electrons into the respiratory chain.
• D-lactate dehydrogenase (cytochrome) activity is important for D-lactate utilization and detoxification, and it has been exploited in biosensors and bioreactors for D-lactate monitoring and removal.
• Expression of the yeast DLD1 gene is regulated by the HAP1 and HAP2/3/4/5 transcription factors in response to carbon source and oxygen availability.
• The enzyme is a useful model for studying mitochondrial electron transfer, flavin cofactor chemistry, and the metabolic integration of D-lactate.
• Research on GO:0004458 benefits from CRISPR-based knockout, point mutation, knock-in, and overexpression models to dissect gene function and develop therapeutic or biotechnological applications.
Description
D-lactate dehydrogenase (cytochrome) activity, defined by the Gene Ontology term GO:0004458, is a molecular function that catalyzes the reaction (R)-lactate + 2 [Fe(III)cytochrome c] = 2 [Fe(II)cytochrome c] + 2 H+ + pyruvate. This activity is distinct from the NAD-dependent lactate dehydrogenases because it transfers electrons directly to cytochrome c, linking D-lactate oxidation to the mitochondrial respiratory chain. The enzyme is best characterized in the yeast Saccharomyces cerevisiae, where it is encoded by the DLD1 gene and localizes to mitochondria. Understanding this activity is important for researchers studying mitochondrial metabolism, D-lactate homeostasis, and the development of biosensors and bioreactors that exploit D-lactate oxidation. The enzyme has also been used as a model to investigate the regulation of mitochondrial gene expression and electron transfer pathways.
D-lactate dehydrogenase (cytochrome) activity At A Glance
| GO ID | GO:0004458 |
|---|---|
| GO term | D-lactate dehydrogenase (cytochrome) activity |
| Ontology | molecular_function |
| Synonym | D-lactate ferricytochrome c oxidoreductase activity; D-lactate-cytochrome c reductase activity; D-lactate (cytochrome) dehydrogenase activity; D-(-)-lactic cytochrome c reductase activity; (R)-lactate:ferricytochrome-c 2-oxidoreductase activity |
| Major function | Oxidation of D-lactate to pyruvate with concomitant reduction of cytochrome c |
| Reaction | (R)-lactate + 2 [Fe(III)cytochrome c] = 2 [Fe(II)cytochrome c] + 2 H+ + pyruvate |
| Cofactor | Flavin adenine dinucleotide (FAD) (inferred from enzyme class) |
| Localization | Mitochondrial (in yeast) |
| Representative gene | DLD1 (Saccharomyces cerevisiae) |
What Is GO:0004458?
GO:0004458 is defined as the catalysis of the reaction: (R)-lactate + 2 [Fe(III)cytochrome c] = 2 [Fe(II)cytochrome c] + 2 H+ + pyruvate. In other words, it is the enzyme activity that oxidizes D-lactate (also known as (R)-lactate) to pyruvate while reducing two molecules of ferricytochrome c to ferrocytochrome c, releasing two protons. This activity is synonymous with D-lactate ferricytochrome c oxidoreductase, D-lactate-cytochrome c reductase, and several other names listed in the QuickGO entry.
Why Is D-lactate dehydrogenase (cytochrome) activity Important in Cell Biology?
GO:0004458 is important because it represents a key enzymatic step in D-lactate metabolism that directly couples to the respiratory chain via cytochrome c, distinguishing it from NAD-dependent lactate dehydrogenases. This activity is critical for D-lactate utilization and detoxification in yeast and other organisms, and it has practical applications in biosensor development and bioremediation of D-lactate. Moreover, the enzyme serves as a model for studying mitochondrial electron transfer, flavin chemistry, and the regulation of mitochondrial gene expression by HAP transcription factors. Understanding this activity can inform metabolic engineering and the design of cell models for studying mitochondrial function and dysfunction.
• Provides a direct link between D-lactate oxidation and the mitochondrial respiratory chain via cytochrome c.
• Enables D-lactate utilization as a carbon source in yeast and potentially other organisms.
• Plays a role in D-lactate detoxification, which is relevant for conditions involving D-lactate accumulation.
• Serves as a target for biosensor development for D-lactate monitoring in clinical and industrial settings.
• Used in bioreactor prototypes for oxidation of toxic D-lactate using recombinant yeast cells.
• Model system for studying mitochondrial electron transfer and flavin-dependent dehydrogenases.
• Regulated by HAP1 and HAP2/3/4/5 transcription factors, linking carbon source and oxygen sensing to mitochondrial function.
• Relevant for understanding mitochondrial metabolism in eukaryotic cells.
• Potential target for metabolic engineering to enhance D-lactate consumption.
• Contributes to the understanding of cytochrome c-mediated electron transfer pathways.
What Happens During D-lactate dehydrogenase (cytochrome) activity?
Substrate binding and oxidation of D-lactate
In simple terms: The enzyme grabs D-lactate and removes electrons from it.
The enzyme binds (R)-lactate (D-lactate) in its active site, where it catalyzes the oxidation of the substrate to pyruvate. This step involves the removal of two electrons and two protons from D-lactate, which are transferred to the flavin cofactor (FAD) within the enzyme.
Electron transfer to cytochrome c
In simple terms: The electrons taken from D-lactate are passed to cytochrome c.
The reduced flavin cofactor then transfers electrons to two molecules of ferricytochrome c (Fe(III)cytochrome c), reducing them to ferrocytochrome c (Fe(II)cytochrome c). This step couples the oxidation of D-lactate to the reduction of cytochrome c, which can then feed electrons into the respiratory chain.
Proton release and product formation
In simple terms: Protons are released and pyruvate is made.
The reaction releases two protons (H+) and produces pyruvate as the final product. The overall reaction is: (R)-lactate + 2 [Fe(III)cytochrome c] = 2 [Fe(II)cytochrome c] + 2 H+ + pyruvate.
Mitochondrial localization and integration
In simple terms: This process happens inside mitochondria.
In Saccharomyces cerevisiae, the enzyme is a mitochondrial protein, and its activity is integrated into mitochondrial metabolism. The DLD1 gene encodes the mitochondrial D-lactate ferricytochrome c oxidoreductase, which is involved in D-lactate utilization and respiration.
Key Genes Involved in GO:0004458 D-lactate dehydrogenase (cytochrome) activity
The following genes and proteins are directly associated with D-lactate dehydrogenase (cytochrome) activity or its regulation, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DLD1 (S. cerevisiae) | Encodes mitochondrial D-lactate ferricytochrome c oxidoreductase | Model for studying D-lactate metabolism and mitochondrial electron transfer |
| HAP1 | Transcription factor regulating DLD1 expression | Links carbon source and oxygen sensing to DLD1 regulation |
| HAP2 | Subunit of HAP2/3/4/5 complex regulating DLD1 | Involved in transcriptional activation of DLD1 |
| HAP3 | Subunit of HAP2/3/4/5 complex regulating DLD1 | Involved in transcriptional activation of DLD1 |
| HAP4 | Subunit of HAP2/3/4/5 complex regulating DLD1 | Involved in transcriptional activation of DLD1 |
| HAP5 | Subunit of HAP2/3/4/5 complex regulating DLD1 | Involved in transcriptional activation of DLD1 |
| AAC1 (S. cerevisiae) | Mitochondrial ADP/ATP carrier | Complements Klaac null mutant in K. lactis, used in mitochondrial studies |
| Klaac (K. lactis) | Mitochondrial ADP/ATP carrier | Null mutant complemented by S. cerevisiae AAC1 |
| Cytochrome c (yeast) | Electron acceptor for D-lactate dehydrogenase | Essential for respiratory chain function |
| FAD (cofactor) | Flavin adenine dinucleotide | Redox cofactor for D-lactate dehydrogenase |
| Pyruvate | Product of D-lactate oxidation | Metabolic intermediate |
| D-lactate | Substrate for the enzyme | Metabolite monitored in biosensors |
| Hansenula polymorpha (recombinant) | Host for overproducing D-lactate cytochrome c oxidoreductase | Used in amperometric biosensor |
| Saccharomyces cerevisiae (recombinant) | Host for overproducing D-lactate cytochrome c oxidoreductase | Used in bioreactor for D-lactate oxidation |
| Kluyveromyces lactis | Yeast model for mitochondrial carrier studies | Klaac null mutant complemented by AAC1 |
| DLD1 promoter | Regulatory region of DLD1 | Studied for HAP-mediated regulation |
| Mitochondrial respiratory chain | Electron transport chain | Accepts electrons from D-lactate dehydrogenase via cytochrome c |
How Is D-lactate dehydrogenase (cytochrome) activity Regulated?
The expression of the DLD1 gene, encoding D-lactate ferricytochrome c oxidoreductase in Saccharomyces cerevisiae, is regulated by the HAP1 and HAP2/3/4/5 transcription factors. HAP1 is a heme-activated transcription factor that responds to oxygen, while the HAP2/3/4/5 complex is a global regulator of respiratory gene expression in response to carbon source. This regulation ensures that DLD1 is expressed under conditions that require mitochondrial respiration, such as growth on non-fermentable carbon sources or in the presence of oxygen. The activity itself is also dependent on the availability of cytochrome c as an electron acceptor and on the redox state of the mitochondrial respiratory chain.
D-lactate dehydrogenase (cytochrome) activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DLD1 (yeast) | D-lactate acidosis (model) | Yeast knockout and overexpression strains |
| DLD1 (yeast) | Mitochondrial dysfunction | Yeast mutants for respiratory chain studies |
| HAP1 | Oxygen sensing and mitochondrial regulation | Yeast HAP1 deletion mutants |
| HAP2/3/4/5 | Carbon source-dependent regulation | Yeast HAP complex mutants |
| AAC1/Klaac | Mitochondrial carrier function | K. lactis null mutant complemented by AAC1 |
D-lactate acidosis and metabolic disorders
D-lactate dehydrogenase (cytochrome) activity is involved in the metabolism of D-lactate, and impaired D-lactate clearance can lead to D-lactate acidosis, a condition observed in short bowel syndrome and other metabolic disorders. The enzyme's ability to oxidize D-lactate to pyruvate is relevant for detoxification, and recombinant yeast cells overproducing this enzyme have been used to oxidize toxic D-lactate. Thus, understanding this activity may inform therapeutic strategies for D-lactate accumulation.
Mitochondrial dysfunction and oxidative stress
Because the enzyme transfers electrons to cytochrome c, it is integrated into the mitochondrial respiratory chain. Defects in this pathway can affect mitochondrial function and contribute to oxidative stress. Studies on the yeast DLD1 gene have provided insights into mitochondrial electron transfer and the regulation of respiratory chain components. This makes the enzyme a model for investigating mitochondrial dysfunction in disease contexts.
Biotechnological and biosensor applications
The enzyme has been exploited in amperometric biosensors for D-lactate detection, using cell debris of recombinant Hansenula polymorpha overproducing D-lactate cytochrome c oxidoreductase. Such biosensors are valuable for clinical monitoring of D-lactate levels and for industrial process control. Additionally, bioreactor prototypes using yeast cells overproducing the enzyme have been developed for oxidation of toxic D-lactate.
From D-lactate dehydrogenase (cytochrome) activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the effect of DLD1 knockout on D-lactate metabolism? | CRISPR knockout of DLD1 in S. cerevisiae |
| How do point mutations in the active site affect enzyme activity? | CRISPR point mutation knock-in of DLD1 |
| Can tagged DLD1 be used to study protein localization? | CRISPR knock-in of fluorescent tag at DLD1 locus |
| What is the effect of DLD1 overexpression on D-lactate utilization? | Overexpression of DLD1 in yeast or mammalian cells |
| How does HAP1 regulate DLD1 expression? | CRISPR knockout of HAP1 followed by DLD1 expression analysis |
| Can the enzyme be used in biosensors? | Recombinant expression in H. polymorpha or S. cerevisiae |
How to Study the D-lactate dehydrogenase (cytochrome) activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Spectrophotometric cytochrome c reduction assay | Enzyme activity | Kinetic characterization of DLD1 |
| Amperometric biosensor | D-lactate concentration | Clinical and industrial D-lactate monitoring |
| Bioreactor oxidation assay | D-lactate removal efficiency | Bioremediation of toxic D-lactate |
| RT-qPCR | DLD1 mRNA levels | Regulation by HAP factors |
| Western blot | Protein expression | Overexpression and knockout validation |
| Fluorescence microscopy | Protein localization | Mitochondrial targeting of DLD1 |
| CRISPR knockout screening | Gene essentiality | Identifying genes required for D-lactate metabolism |
| CRISPR point mutation knock-in | Functional domains | Dissecting catalytic residues |
Enzymatic activity assays
D-lactate dehydrogenase (cytochrome) activity can be measured spectrophotometrically by monitoring the reduction of cytochrome c at 550 nm, using D-lactate as substrate. This assay is based on the increase in absorbance upon reduction of ferricytochrome c to ferrocytochrome c. Such assays are essential for characterizing enzyme kinetics and mutant variants.
Amperometric biosensors
Amperometric biosensors using cell debris of recombinant yeast overproducing D-lactate cytochrome c oxidoreductase have been developed for selective D-lactate detection. These biosensors measure current generated by the enzymatic oxidation of D-lactate and are useful for clinical and industrial monitoring.
Bioreactor studies
Laboratory prototypes of bioreactors using yeast cells overproducing D-lactate cytochrome c oxidoreductase have been used for the oxidation of toxic D-lactate. These studies evaluate the efficiency of D-lactate removal and the scalability of the process.
Gene expression analysis
Regulation of the DLD1 gene can be studied by Northern blot, RT-qPCR, or reporter assays under different carbon sources and oxygen conditions. The roles of HAP1 and HAP2/3/4/5 have been dissected using deletion mutants and promoter analysis.
How CRISPR Can Be Used to Study GO:0004458 D-lactate dehydrogenase (cytochrome) activity
Knockout
CRISPR knockout of DLD1 in Saccharomyces cerevisiae can be used to create null mutants to study the role of D-lactate dehydrogenase (cytochrome) activity in D-lactate metabolism and mitochondrial function. Such knockouts can be validated by enzymatic assays and growth phenotyping on D-lactate as a carbon source.
Point Mutation
CRISPR point mutation knock-in can be used to introduce specific amino acid substitutions in the DLD1 active site to dissect catalytic residues involved in substrate binding and electron transfer to cytochrome c. This approach helps define the molecular mechanism of the enzyme.
Knock-in
CRISPR knock-in of epitope tags or fluorescent proteins at the endogenous DLD1 locus allows for real-time visualization of protein localization and interaction studies. This can confirm mitochondrial targeting and facilitate proteomic analysis.
Overexpression
CRISPR activation or plasmid-based overexpression of DLD1 can be used to increase D-lactate dehydrogenase (cytochrome) activity for biotechnological applications, such as bioreactors for D-lactate oxidation or biosensor development.
How EDITGENE Supports D-lactate dehydrogenase (cytochrome) activity Research
Researchers studying D-lactate dehydrogenase (cytochrome) activity-related genes often need to determine whether a candidate gene is causally involved in D-lactate metabolism, mitochondrial function, or related diseases. EDITGENE provides a comprehensive suite of CRISPR-based services to create precise cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for D-lactate dehydrogenase (cytochrome) activity research.
Frequently Asked Questions About D-lactate dehydrogenase (cytochrome) activity
What is D-lactate dehydrogenase (cytochrome) activity?
It is the enzyme activity defined by GO:0004458 that catalyzes the oxidation of D-lactate to pyruvate while reducing cytochrome c, as described in the Gene Ontology.
What genes are involved in D-lactate dehydrogenase (cytochrome) activity?
The primary gene is DLD1 in Saccharomyces cerevisiae, which encodes the mitochondrial D-lactate ferricytochrome c oxidoreductase. Its expression is regulated by HAP1 and HAP2/3/4/5.
What is the reaction catalyzed by D-lactate dehydrogenase (cytochrome)?
The reaction is: (R)-lactate + 2 [Fe(III)cytochrome c] = 2 [Fe(II)cytochrome c] + 2 H+ + pyruvate.
Where is D-lactate dehydrogenase (cytochrome) located in the cell?
In yeast, it is a mitochondrial protein, as shown by studies on the DLD1 gene product.
How is D-lactate dehydrogenase (cytochrome) activity regulated?
The DLD1 gene is regulated by the HAP1 and HAP2/3/4/5 transcription factors in response to carbon source and oxygen availability.
What diseases are associated with D-lactate dehydrogenase (cytochrome) activity?
D-lactate acidosis and mitochondrial dysfunction are potential areas of relevance, as the enzyme is involved in D-lactate detoxification and mitochondrial electron transfer.
How can I measure D-lactate dehydrogenase (cytochrome) activity?
It can be measured spectrophotometrically by monitoring cytochrome c reduction at 550 nm, or via amperometric biosensors using recombinant yeast.
What are the applications of D-lactate dehydrogenase (cytochrome) in biotechnology?
It is used in biosensors for D-lactate detection and in bioreactors for oxidation of toxic D-lactate.
Can CRISPR be used to study D-lactate dehydrogenase (cytochrome) activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression can be used to create cell models to study the function of DLD1 and its regulators.
What model organisms are used to study D-lactate dehydrogenase (cytochrome) activity?
Saccharomyces cerevisiae and Hansenula polymorpha are commonly used, as well as Kluyveromyces lactis for mitochondrial carrier studies.
Conclusion
GO:0004458 D-lactate dehydrogenase (cytochrome) activity represents a key enzymatic function that links D-lactate metabolism to the mitochondrial respiratory chain. Studies in yeast have elucidated its genetic regulation and biochemical properties, and its applications extend to biosensors and bioreactors. Understanding this activity provides insights into mitochondrial function and offers opportunities for metabolic engineering and therapeutic development.
References
- 1. Karkovska M et al.. 2016. Laboratory Prototype of Bioreactor for Oxidation of Toxic D-Lactate Using Yeast Cells Overproducing D-Lactate Cytochrome c Oxidoreductase.. Biomed Res Int 2016:4652876 PMID: 27446952
- 2. Smutok OV et al.. 2014. d-lactate-selective amperometric biosensor based on the cell debris of the recombinant yeast Hansenula polymorpha.. Talanta 125:227-32 PMID: 24840438
- 3. Lodi T et al.. 1993. Isolation of the DLD gene of Saccharomyces cerevisiae encoding the mitochondrial enzyme D-lactate ferricytochrome c oxidoreductase.. Mol Gen Genet 238(3):315-24 PMID: 8492799
- 4. Lodi T et al.. 1999. Regulation of the Saccharomyces cerevisiae DLD1 gene encoding the mitochondrial protein D-lactate ferricytochrome c oxidoreductase by HAP1 and HAP2/3/4/5.. Mol Gen Genet 262(4-5):623-32 PMID: 10628845
- 5. Viola AM et al.. 1999. A Klaac null mutant of Kluyveromyces lactis is complemented by a single copy of the Saccharomyces cerevisiae AAC1 gene.. Curr Genet 36(1-2):29-36 PMID: 10447592
