Oxidative phosphorylation (OXPHOS) produces more than 95% of a cell's energy in the form of ATP under normal physiological conditions. This process involves five different protein complexes, Complex I-V.
Contents
- Subunits in the Oxidative Phosphorylation pathway
- Antibodies to Complex I-V
- Other useful antibodies
- Assay kits
1. Subunits in the Oxidative Phosphorylation pathway
The total number of polypeptides involved directly in OXPHOS is 91 when cytochrome c is included. There are additional proteins required for efficient OXPHOS including those for stability, replication and transcription of mtDNA, those in the mt ribosome, ones that synthesize the heme, flavin and non-heme iron co-factors and multiple proteins acting in assembly of each of the complexes.
View our comprehensive list of antibodies to subunits in the Oxidative Phosphorylation pathway:
In all, close to 300 proteins are needed for efficient OXPHOS activity.The overall process of oxidative phosphorylation is tightly controlled by transcriptional regulation at the level of DNA, translational effects via RNA levels and stability, by substrate feedback inhibition, and by post-translational modifications including phosphorylation and acetylation.
Inefficient electron transfer through complexes I-IV causes human disease in part because of loss of energy metabolism but also because insults to the various enzymes, particularly Complexes I, II and III induce production of toxic reactive oxygen species. Defects of complex V are also a cause of mitochondrial dysfunction.
| Complex I NADH dehydrogenase | Complex II Succinate ubiquinone oxidoreductase | Complex III Ubiquinol Cytochrome c Oxidoreductase | Complex IV Cytochrome c Oxidoreductase | Complex V ATP Synthase | |
|---|---|---|---|---|---|
| Subunits | 45 | 4 | 11 | 13 | 17 |
| Polypeptides encoded on mtDNA | 7 | 0 | 1 | 3 | 2 |
| Polypeptides encoded on nuclear DNA | ~40 | 4 | 10 | 10 | 15 |
| Disease Associations | Complex I dysfunction is a common cause of genetic OXPHOS defects. Altered functioning of this complex is also thought to contribute to several neurological disorders including Parkinson's disease and schizophrenia. Also there is evidence of Complex I involvement in diabetes. | Complex II deficiencies are seen in OXPHOS genetic disease and found in a type of cancer called paraganglioma. | Genetic complex III deficiencies occur but are rare. | Genetic alterations of this enzyme complex are a common cause of OXPHOS diseases. The enzyme is altered in Alzheimer's disease, and there are reports of reduced amounts of this complex in cancer cells when these cells become hypoxic. | Mutations in the mt-encoded subunits of ATP synthase (Complex V) cause OXPHOS disease. ATP synthase has also been found on the surface of cancer cells. |
There are inborn errors of metabolism due to deficiencies in each of the 5 complexes, which total as many as 1 in 5000 live births. Of these, Complex I and Complex IV deficiency are most common. Many of the late onset diseases of humans are now thought to involve compromised oxidative phosphorylation, including diabetes, Parkinson's disease, Alzheimer's, cancer, and the ageing process itself. Further, many diverse classes of drugs inhibit oxidative phosphorylation. Not surprisingly, the ability to monitor the amount and activities of the 5 oxidative phosphorylation complexes is paramount in diagnosing and characterizing diseases presenting with energy deficit, and these assays need to be a key part of drug development and drug toxicity studies. MitoSciences has the only extensive line of reagents and assays for this purpose.
2. Antibodies to Complex I-V
| NADH dehydrogenase 1 alpha subcomplex | NADH dehydrogenase 1 beta subcomplex | NADH dehydrogenase Fe-S protein | NADH dehydrogenase flavoprotein 1 | Mitochondrially encoded NADH dehydrogenase subunit |
|---|---|---|---|---|
| Complex I subunit 8 kDa | NDUFB1 | Ndufs1 | NDUFV1 | MT-ND1 |
| NDUFA1 | NDUFB3 | NDUFS2 | NDUFV2 | NADH2 |
| NDUFA2 | NDUFB4 | NDUFS3 | NDUFV3 | NADH dehydrogenase subunit 4 |
| NDUFA3 | NDUFB5 | NDUFS4 | MT-ND5 | |
| NDUFA4L2 | NDUFB6 | NDUFS5 | NADH Dehydrogenase subunit 6 | |
| NDUFA5 | NDUFB7 | NDUFS6 | ||
| NDUFA6 | NDUFB8 | NDUFS7 | ||
| NDUFA7 | NDUFB9 | NDUFS8 | ||
| NDUFA8 | NDUFB10 | |||
| NDUFA9 | NDUFB11 | |||
| NDUFA10 | NDUFC2 | |||
| NDUAB | ||||
| GRIM-19 | ||||
| NDUFAB1 | ||||
| Mimitin | ||||
| NDUFAF4 |
Complex II, III, IV & V
| Complex II Succinate ubiquinone oxidoreductase | Complex III Ubiquinol Cytochrome c Oxidoreductase | Complex IV Cytochrome c Oxidoreductase | Complex V ATP Synthase |
|---|---|---|---|
| Complex II subunit 30 kDa | Ubiquinol-Cytochrome C Reductase Core Protein I | MTCO I | ATP5A |
| Complex II subunit 70 kDa | UQCRC2 | Cytochrome C oxidase subunit II | ATPB |
| SDHB | UQCRFS1 | Cytochrome C oxidase subunit III | ATP5H |
| UQCRQ | Cytochrome c oxidase subunit IV | ATP5O | |
| COX5A | ATPase Inhibitory Factor 1 | ||
| COX5B | ATP5J | ||
| Complex IV subunit VIIaHL | |||
| Cytochrome C Oxidase subunit VIb | |||
| Cytochrome C Oxidase subunit VIc | |||
| COX6A1 | |||
| COX6A2 | |||
| COX7B | |||
| Surf1 |
3. Other useful antibodies
| Name |
|---|
| NNT |
| MADD |
| Cytochrome C |
4. Assays and Kits
| Name | Applications/Tests | Species | Product code |
|---|---|---|---|
| MitoProfile® Total OXPHOS Human WB Antibody Cocktail | WB | Hu | ab110411 |
| Complex I Immunocapture Kit | IP | Hu, Ms, Rat, Cow | ab109711 |
| Complex II Immunocapture Kit | IP | Hu, Ms, Rat, Cow | ab109799 |
| Complex III Immunocapture Kit | IP | Hu, Ms, Rat, Cow | ab109800 |
| Complex IV Immunocapture Kit | IP | Hu, Ms, Rat, Cow | ab109801 |
| ATP synthase Immunocapture Kit | IP | Hu, Ms, Rat, Cow | ab109715 |
| MitoTox™ Complex I OXPHOS Activity Microplate Assay | 1x 96 tests | Cow | ab109903 |
| MitoTox™ Complex II OXPHOS Activity Microplate Assay | 1x 96 tests | Cow | ab109904 |
| MitoTox™ Complex III OXPHOS Activity Microplate Assay | 1x 96 tests | Cow | ab109905 |
| MitoTox™ Complex IV OXPHOS Activity Microplate Assay | 1x 96 tests | Cow | ab109906 |
| MitoTox™ Complex V OXPHOS Activity Microplate Assay | 1x 96 tests | Cow | ab109907 |
| Cytochrome c Protein Quantity Microplate Assay Kit | 1x 96 tests | Hu, Ms, Rat, Cow | ab110172 |
| Complex I Enzyme Activity Microplate Assay Kit | 1x 96 tests | Hu, Ms, Rat, Cow | ab109721 |
| Complex II Enzyme Activity Microplate Assay Kit | 1x 96 tests | Hu, Ms, Rat, Cow | ab109908 |
| Complex IV Human Enzyme Activity Microplate Assay Kit | 1x 96 tests | Hu, Cow | ab109909 |
| ATP synthase Enzyme Activity Microplate Assay Kit | 1x 96 tests | Hu, Rat, Cow | ab109714 |
| ATP synthase Specific Activity Microplate Assay Kit | FuncS | Hu, Rat, Cow | ab109716 |
| Complex I Enzyme Activity Dipstick Assay Kit | FuncS | Hu, Ms, Rat, Cow | ab109720 |
| Complex IV Rodent Enzyme Activity Dipstick Assay Kit | FuncS | Hu, Cow | ab109878 |
| Complex IV Human Enzyme Activity Dipstick Assay Kit | FuncS | Hu, Cow | ab109876 |
| Complex I Human Protein Quantity Dipstick Assay Kit | FuncS | Hu, Cow | ab109722 |
| Complex I Rodent Protein Quantity Dipstick Assay Kit | FuncS | Hu, Ms, Rat, Cow | ab109875 |
| Complex IV Human Protein Quantity Dipstick Assay Kit | FuncS | Hu, Cow | ab109877 |
| Luminescent ATP Detection Assay Kit | FuncS | ab113849 | |
| JC1 - Mitochondrial Membrane Potential Assay Kit | FuncS | ab113850 | |
| DCFDA - Cellular Reactive Oxygen Species Detection Assay Kit | FuncS | ab113851 | |
| TMRE—Mitochondrial Membrane Potential Assay Kit | FuncS | ab113852 |
