Recombinant Human MCFD2 Protein: Handling & Usage Protocol

Recombinant Human MCFD2 Protein is a calcium-binding secretory pathway component essential for the efficient endoplasmic reticulum export of coagulation factors V and VIII, making it a critical research tool for studying hereditary combined deficiency of factors V and VIII (F5F8D) and intracellular protein trafficking mechanisms.

Product SKU

rp369476

Protein Name

Recombinant Human MCFD2 (Multiple Coagulation Factor Deficiency Protein 2)

Biological Function

Forms a cargo receptor complex with LMAN1 (ERGIC-53) to facilitate ER-to-Golgi transport of coagulation factors V and VIII

Disease Relevance

Mutations in MCFD2 cause combined deficiency of coagulation factors V and VIII (F5F8D)

Calcium Dependency

MCFD2 contains EF-hand calcium-binding motifs; calcium is required for LMAN1 interaction and proper folding

Recommended Storage

-80°C for long-term storage; avoid repeated freeze-thaw cycles

Background and Biological Significance of MCFD2

Multiple Coagulation Factor Deficiency Protein 2 (MCFD2) is a small, soluble protein of approximately 16 kDa that resides in the endoplasmic reticulum–Golgi intermediate compartment (ERGIC). It functions as an obligate co-receptor with LMAN1 (also known as ERGIC-53), forming a 2:1 (MCFD2:LMAN1) heteromeric cargo receptor complex. This complex selectively captures coagulation factor V (FV) and factor VIII (FVIII) in the lumen of the endoplasmic reticulum and escorts them through the secretory pathway to the Golgi apparatus.

MCFD2 harbors two EF-hand calcium-binding motifs in its C-terminal domain, and calcium occupancy is required for the MCFD2–LMAN1 interaction as well as for cargo recognition. Loss-of-function mutations in MCFD2 (or in LMAN1) cause the autosomal recessive bleeding disorder known as combined deficiency of coagulation factors V and VIII (F5F8D, OMIM #227300), characterized by simultaneous plasma reductions of both FV and FVIII to approximately 5–30% of normal levels.

Recombinant Human MCFD2 Protein is therefore a valuable reagent for biochemical characterization of the LMAN1–MCFD2 complex, structure–function studies of EF-hand domains, investigation of ER quality-control and cargo export mechanisms, and drug-discovery efforts targeting the coagulation pathway or intracellular trafficking.

Reconstitution and Storage Recommendations

Reconstitution: Prior to use, briefly centrifuge the vial at low speed (e.g., 1,000 × g, 30 seconds) to collect lyophilized material at the bottom. Reconstitute the protein in sterile, ultrapure water or an appropriate aqueous buffer (e.g., 20 mM Tris-HCl, pH 7.4, 150 mM NaCl, 1 mM CaCl₂). The inclusion of 1–2 mM CaCl₂ in the reconstitution buffer is strongly recommended to support EF-hand domain integrity and protein stability. Allow the solution to stand for 10 minutes at room temperature with gentle mixing; do not vortex vigorously.

Working Concentration: Determine empirically for each assay. As a general guide for interaction studies (e.g., co-immunoprecipitation, surface plasmon resonance), concentrations in the range of 0.1–10 µg/mL are typical starting points.

Storage: Aliquot reconstituted protein into single-use volumes to minimize freeze-thaw cycles. Store aliquots at −80°C for long-term use (up to 12 months recommended). Short-term storage at 4°C (up to 1 week) is acceptable when supplemented with a carrier protein such as 0.1% BSA to prevent surface adsorption losses. Avoid repeated freeze-thaw cycles, which degrade activity and promote aggregation.

Shipping: The product is shipped on dry ice. Upon receipt, immediately transfer to −80°C if not used within 24 hours.

Applications and Assay Compatibility

Recombinant Human MCFD2 Protein is suitable for a range of biochemical and cell-biology applications:

• Protein–Protein Interaction Studies: MCFD2 is routinely used to characterize its interaction with LMAN1 by techniques including co-immunoprecipitation (Co-IP), pull-down assays, isothermal titration calorimetry (ITC), and surface plasmon resonance (SPR). Calcium (1–2 mM) should be maintained in all binding buffers.
• ELISA and Western Blot (as standard or antigen): Recombinant MCFD2 can serve as a positive control antigen or immunization standard in ELISA-based detection systems and for antibody validation by Western blot.
• Structural Studies: High-purity recombinant MCFD2 is compatible with circular dichroism (CD) spectroscopy for secondary structure analysis and with crystallography or cryo-EM sample preparation when purity and homogeneity requirements are met.
• Cell-Free Reconstitution Assays: MCFD2 can be incorporated into cell-free systems designed to reconstitute ERGIC-dependent cargo export, enabling mechanistic dissection of the LMAN1–MCFD2–FV/FVIII axis.
• Drug Screening: As an ER cargo receptor component, MCFD2 may serve as a target or counter-screen reagent in assays seeking to modulate FV/FVIII secretion for therapeutic benefit in bleeding or thrombotic disorders.

Quality Control and Purity Considerations

To ensure experimental reproducibility, verify the following quality attributes upon receipt and before use:

• Purity: Confirm protein purity by SDS-PAGE under reducing conditions. A single predominant band at the expected molecular weight (~16 kDa for the mature MCFD2 core, though tags or expression system differences may alter observed MW) should be visible. Purity should ideally be ≥90% as assessed by densitometry.
• Identity: Verify protein identity by Western blot using a validated anti-MCFD2 antibody, or by mass spectrometry peptide mapping if high confidence is required.
• Endotoxin Level: For cell-based assays, confirm endotoxin levels are below the threshold acceptable for the assay system (typically <1 EU/µg). Check the Certificate of Analysis (CoA) provided with the product.
• Aggregation: Assess homogeneity by dynamic light scattering (DLS) or size-exclusion chromatography (SEC) if assay sensitivity to aggregation is high.
• Calcium Content: Because MCFD2 activity and folding are calcium-dependent, ensure calcium is not chelated by EDTA or EGTA present in lysis or storage buffers. Replace EDTA-containing buffers with calcium-supplemented alternatives before use.

Always consult the Certificate of Analysis (CoA) shipped with each lot for lot-specific purity, concentration, and QC data.

Safety, Disposal, and Regulatory Notes

Safety: Recombinant Human MCFD2 Protein is a research-grade reagent derived from a recombinant expression system. Handle according to standard laboratory biosafety practices for recombinant proteins. Wear appropriate personal protective equipment (gloves, lab coat, eye protection). Although the protein itself is not classified as a biohazard, treat all human-derived recombinant proteins with appropriate caution per institutional biosafety guidelines.

Disposal: Dispose of protein solutions and contaminated materials in accordance with applicable local, national, and institutional regulations governing biological and chemical waste. Inactivation by autoclaving or chemical denaturation prior to disposal is recommended where required by institutional policy.

Regulatory: This product is intended for research use only (RUO) and is not approved for use in diagnostic, therapeutic, or clinical procedures. It has not been evaluated by regulatory authorities (e.g., FDA, EMA) for clinical applications. Researchers are responsible for ensuring compliance with all applicable regulations governing the import, use, and disposal of recombinant proteins in their jurisdiction.

Frequently asked questions

Why is calcium important when working with Recombinant Human MCFD2 Protein?

MCFD2 contains two EF-hand calcium-binding motifs that are essential for its proper folding, stability, and interaction with LMAN1. In the absence of calcium (or in the presence of chelating agents such as EDTA or EGTA), MCFD2 loses its ability to bind LMAN1 and may partially unfold. Always include 1–2 mM CaCl₂ in reconstitution, storage, and assay buffers, and avoid calcium-chelating agents.

What expression system is used to produce Recombinant Human MCFD2 Protein, and does it affect glycosylation?

The specific expression system for rp369476 should be confirmed in the product's Certificate of Analysis or datasheet. Common systems for recombinant MCFD2 include E. coli (which yields non-glycosylated protein) and mammalian or insect cell systems (which support post-translational modifications). Native MCFD2 is not known to be heavily glycosylated; however, researchers requiring post-translational modifications identical to the native protein should verify the expression host before use.

Can Recombinant Human MCFD2 Protein be used to study F5F8D disease mutations?

Yes. Wild-type Recombinant Human MCFD2 serves as an essential reference or control in studies investigating the structural and functional consequences of MCFD2 mutations associated with combined deficiency of factors V and VIII (F5F8D). By comparing wild-type MCFD2 with recombinant mutant variants (expressed separately), researchers can quantitatively assess changes in LMAN1-binding affinity, calcium coordination, thermal stability, and cargo-export efficiency.

How should I validate that the reconstituted MCFD2 protein is functional before proceeding with experiments?

A recommended functional validation step is a pull-down or co-immunoprecipitation assay using recombinant LMAN1 (the known binding partner) in a calcium-containing buffer. Functional MCFD2 should bind LMAN1 in a calcium-dependent manner and show reduced or absent binding upon addition of EDTA. Additionally, SDS-PAGE and Western blot under reducing conditions can confirm intact molecular weight and identity prior to functional testing.

What is the difference between MCFD2 and LMAN1, and do I need both for my experiment?

LMAN1 (ERGIC-53) is a type I transmembrane lectin that forms the structural scaffold of the cargo receptor complex, while MCFD2 is a soluble luminal co-receptor that confers specificity for coagulation factors V and VIII. Mutations in either protein independently cause F5F8D. Whether you need both depends on your assay: studies of complex formation, cooperative cargo binding, or ER export reconstitution require both proteins, whereas studies focused solely on MCFD2 EF-hand function or antibody validation may require only MCFD2.

References

1. Zhang B, Cunningham MA, Nichols WC, et al. Bleeding due to disruption of a cargo-specific ER-to-Golgi transport complex. Nat Genet. 2003;34(2):220-225. doi:10.1038/ng1153
2. Nyfeler B, Zhang B, Bhatt DL, et al. Cargo selectivity of the ERGIC-53/MCFD2 transport receptor complex. Traffic. 2008;9(8):1473-1481. doi:10.1111/j.1600-0854.2008.00779.x
3. Kawasaki N, Ichikawa A, Hashii N, et al. The sugars of MCFD2 are essential for recognition by and lectin activity of ERGIC-53. Glycobiology. 2008;18(2):177-188.
4. Wigren E, Bourhis JM, Kursula I, et al. Crystal structure of the LMAN1-CRD/MCFD2 transport receptor complex provides insight into combined deficiency of coagulation factors V and VIII. FEBS Lett. 2010;584(5):878-882. doi:10.1016/j.febslet.2009.12.055

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.