Recombinant Human GCDH Protein: Research Guide & Protocol
Recombinant Human GCDH Protein: Research Guide & Protocol
Recombinant Human GCDH Protein is a mitochondrial flavoenzyme that catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA, serving as a critical tool for biochemical, metabolic, and disease-mechanism research related to glutaric acidemia type 1.
- Protein Name
- Recombinant Human GCDH (Glutaryl-CoA Dehydrogenase) Protein
- SKU
- rp374277
- Biological Function
- Catalyzes oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA in lysine, hydroxylysine, and tryptophan catabolism
- Subcellular Localization
- Mitochondrial matrix
- Cofactor
- FAD (Flavin Adenine Dinucleotide)
- Disease Relevance
- Loss-of-function mutations in GCDH cause Glutaric Acidemia Type 1 (GA1), an autosomal recessive organic acidemia
- Recommended Storage
- -20°C or -80°C; avoid repeated freeze-thaw cycles (verify with CoA)
Protein Identity and Biological Background
Glutaryl-CoA Dehydrogenase (GCDH; UniProt Q92947) is a nuclear-encoded mitochondrial matrix enzyme belonging to the acyl-CoA dehydrogenase (ACAD) family. It functions as a homotetrameric flavoprotein, with each subunit non-covalently binding one molecule of FAD as its essential cofactor.
GCDH occupies a central position in the catabolic pathways of the amino acids L-lysine, L-hydroxylysine, and L-tryptophan. Its primary catalytic activity is the oxidative decarboxylation of glutaryl-CoA to yield crotonyl-CoA and CO2, coupled to the reduction of FAD to FADH2, which subsequently feeds electrons into the mitochondrial electron transport chain via the electron transfer flavoprotein (ETF).
Mutations in the GCDH gene lead to accumulation of glutaric acid, 3-hydroxyglutaric acid, and glutarylcarnitine, underpinning the pathology of Glutaric Acidemia Type 1 (GA1; OMIM #231670), a rare autosomal recessive neurometabolic disorder that primarily affects the developing striatum.
Product Specifications and Quality Attributes
Recombinant Human GCDH Protein (SKU: rp374277) is manufactured using recombinant expression technology to deliver consistent, research-grade material. Key quality attributes typically assessed for this class of protein include:
- Purity: Assessed by SDS-PAGE and/or HPLC; high-purity preparations are expected for enzymatic and binding studies. Confirm the exact purity specification on the Certificate of Analysis (CoA) supplied with each lot.
- Biological Activity: Functional GCDH activity can be confirmed by a coupled spectrophotometric assay monitoring DCPIP or ETF reduction in the presence of glutaryl-CoA substrate.
- Endotoxin Level: Endotoxin content should be verified on the CoA, particularly for cell-based assay applications.
- Formulation: Refer to the product CoA or datasheet for buffer composition, protein concentration, and the presence of stabilizing excipients (e.g., glycerol, BSA). Do not assume formulation details without consulting the CoA.
Each production lot is accompanied by a CoA; always cross-reference the CoA for lot-specific data before experimental use.
Recommended Handling and Storage Protocol
Proper handling of recombinant proteins is essential to preserve biological activity and ensure reproducible results. Follow the guidelines below for Recombinant Human GCDH Protein:
- Upon Receipt: Inspect the shipment immediately. Note whether the product is shipped on dry ice or wet ice; refer to the product datasheet for the intended shipping condition.
- Short-term Storage: If the protein will be used within 1–2 weeks, store at 4°C. Consult the CoA for the recommended short-term storage buffer.
- Long-term Storage: Aliquot the protein into single-use volumes to minimize freeze-thaw cycles, then store at -20°C or -80°C as specified on the CoA.
- Freeze-Thaw Cycles: Minimize repeated freeze-thaw cycles, as each cycle can degrade enzymatic activity and protein integrity. Prepare small working aliquots at the time of first use.
- Working Concentration: Centrifuge briefly before opening. Dilute in a compatible buffer as indicated on the CoA or datasheet. Avoid vigorous vortexing; mix gently by pipetting.
- Carrier Protein: If the formulation does not contain BSA or another stabilizer, consider adding a carrier protein at 0.1% BSA for dilute working solutions to prevent adsorption to plasticware.
Note: All specific temperatures, concentrations, and buffer details should be confirmed on the lot-specific CoA supplied with the product.
Research Applications
Recombinant Human GCDH Protein is a versatile reagent applicable across multiple research domains:
- Enzyme Kinetics and Biochemistry: Determination of kinetic parameters (Km, Vmax, kcat) for glutaryl-CoA dehydrogenation; characterization of substrate specificity and inhibitor profiling.
- Structural Biology: Use as a reference standard or in structural studies (X-ray crystallography, cryo-EM) to elucidate GCDH oligomeric assembly and active-site architecture.
- Disease Mechanism Research (GA1): Investigation of how pathogenic missense mutations affect GCDH folding, stability, activity, and mitochondrial import; mechanistic studies on metabolite toxicity (glutaric acid, 3-hydroxyglutaric acid).
- Protein–Protein Interaction Studies: Mapping interaction interfaces with ETF subunits and mitochondrial chaperones involved in GCDH biogenesis.
- Drug Discovery and Inhibitor Screening: High-throughput or targeted screening of small-molecule modulators relevant to organic acidemia therapeutic strategies.
- Antibody Validation: Use as a positive control antigen for validating anti-GCDH antibodies in Western blot, ELISA, or immunoprecipitation assays.
- In Vitro Reconstitution: Reconstitution of the lysine oxidation pathway segment in cell-free systems for metabolic flux analysis.
Troubleshooting Common Issues
The following troubleshooting guidance addresses frequently encountered challenges when working with Recombinant Human GCDH Protein:
| Observation | Probable Cause | Recommended Action |
|---|---|---|
| Low or absent enzymatic activity | Degradation due to improper storage or excessive freeze-thaw cycles | Use freshly thawed aliquot; confirm storage at recommended temperature per CoA; check FAD cofactor supplementation in assay buffer |
| Precipitation or aggregation | Protein concentration too high; incompatible buffer; freeze-thaw damage | Centrifuge at 10,000–14,000 × g for 5 min at 4°C; dilute to working concentration; use CoA-recommended buffer |
| Unexpected band size on SDS-PAGE | Post-translational processing; tag cleavage status; glycosylation (if applicable) | Compare against expected molecular weight per datasheet; consult CoA for band pattern reference |
| High background in ELISA or Western blot | Protein aggregation or non-specific binding | Add 0.05–0.1% Tween-20 and blocking agent; titrate protein concentration |
| Inconsistent results between lots | Lot-to-lot variability | Always request and review the CoA; run a parallel comparison experiment; contact Aladdin Scientific technical support |
Frequently asked questions
What is the enzymatic function of GCDH and why is it important for research?
GCDH (Glutaryl-CoA Dehydrogenase) catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA within the mitochondrial catabolism of lysine, hydroxylysine, and tryptophan. Its importance lies in its role as the defective enzyme in Glutaric Acidemia Type 1 (GA1), making it a prime target for mechanistic, metabolic, and therapeutic research into this neurometabolic disease.
How should Recombinant Human GCDH Protein (rp374277) be stored to maintain activity?
For long-term storage, aliquot the protein into single-use volumes and store at -20°C or -80°C as specified on the lot-specific Certificate of Analysis (CoA). Avoid repeated freeze-thaw cycles, which can degrade enzymatic activity. For short-term use within one to two weeks, storage at 4°C may be appropriate; always confirm conditions on the CoA supplied with your specific lot.
What assay formats are suitable for measuring GCDH enzymatic activity?
GCDH activity is commonly measured using a coupled spectrophotometric assay in which the reduction of an artificial electron acceptor such as DCPIP (2,6-dichlorophenolindophenol) or the natural electron acceptor ETF is monitored at the appropriate absorbance wavelength in the presence of glutaryl-CoA. Fluorescence-based ETF reduction assays offer increased sensitivity. Confirm substrate and buffer compatibility with the specific lot's CoA data before establishing your assay.
Can Recombinant Human GCDH Protein be used as a positive control in immunoassays?
Yes, recombinant GCDH protein is well-suited as a positive control antigen for validating anti-GCDH antibodies in Western blot, ELISA, and immunoprecipitation experiments. Ensure the recombinant protein construct shares the epitope region recognized by your antibody of interest, particularly if a purification tag is present.
What should I do if I observe protein aggregation after thawing?
If aggregation is observed, centrifuge the thawed protein at 10,000–14,000 × g for 5 minutes at 4°C to pellet aggregates, then use the clarified supernatant. Ensure protein is thawed slowly on ice and diluted into a compatible buffer as recommended on the CoA. If aggregation persists, contact Aladdin Scientific technical support, as this may indicate a compromised lot.
References
- Goodman SI, Frerman FE. Organic acidemias due to defects in lysine oxidation: 2-ketoadipic acidemia and glutaric acidemia. In: Scriver CR et al., eds. The Metabolic and Molecular Bases of Inherited Disease. 8th ed. McGraw-Hill; 2001.
- Kolker S, et al. The phenotypic spectrum of organic acidurias and urea cycle disorders. Part 1: the initial presentation. J Inherit Metab Dis. 2015;38(6):1041-1057. doi:10.1007/s10545-015-9839-3
- Lenich AC, Goodman SI. The purification and characterization of glutaryl-coenzyme A dehydrogenase from porcine and human liver. J Biol Chem. 1986;261(9):4090-4096. PMID:3958940
- UniProt Consortium. UniProtKB entry Q92947 (GCDH_HUMAN). UniProt. Accessed 2024. https://www.uniprot.org/uniprot/Q92947
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.
危险品化学品经营许可证（带存储）