| Source: |
Escherichia coli |
| Molecular Weight: |
Approximately 12.5 kDa, a single non-glycosylated polypeptide chain containing 115 amino acids. |
| AA Sequence: |
MPMFIVNTNV PRASVPDGFL SELTQQLAQA TGKPPQYIAV HVVPDQLMAF GGSSEPCALC SLHSIGKIGG AQNRSYSKLL CGLLAERLRI SPDRVYINYY DMNAANVGWN NSTFA |
| Purity: |
≥ 95 by SDS-PAGE. |
| Biological Activity: |
Fully biologically active when compared to standard. The specific activity is determined by binding rhCD74 in a functional ELISA. |
| Physical Appearance: |
Sterile filtered white lyophilized (freeze-dried) powder. |
| Formulation: |
Lyophilized from a 0.2 µm filtered concentrated solution in PBS, pH7.4. with 5% trehalose, 0.02% Tween-80. |
| Endotoxin: |
Less than 1 EU/µg of rHuMIF as determined by LAL method. |
| Reconstitution: |
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20°C. Further dilutions should be made in appropriate buffered solutions. |
| Stability & Storage: |
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
12 months from date of receipt, -20 to -70°C as supplied.
1 month, 2 to 8°C under sterile conditions after reconstitution.
3 months, -20 to -70°C under sterile conditions after reconstitution. |
| Synonyms: |
GLF, L-dopachrome Isomerase, Phenylpyruvate Tautomerase |
| Background: |
Migration Inhibitory Factor (MIF) is a secreted protein that lacks a cleavable signal sequence and is released through a specialized, non-classical pathway. Macrophages secrete MIF in response to stimulation by bacterial lipopolysaccharide (LPS) or M. tuberculosis antigens. The protein structure of MIF includes two α-helices and six β-strands, with four of the β-strands forming a β-sheet. The remaining two β-strands interact with other MIF molecules to form a trimer.
Structure-function studies indicate that MIF is bifunctional with distinct topologies. The N- and C-termini are theorized to mediate enzymatic activity. MIF demonstrates phenylpyruvate tautomerase activity, which converts enol to keto form, dependent on the proline at position 1. Additionally, amino acids 50-65 are suggested to possess thiol-protein oxidoreductase activity. MIF has proinflammatory cytokine activity, particularly involving amino acids 49-65. On fibroblasts, MIF induces the expression of IL-1, IL-8, and MMP; on macrophages, it stimulates nitric oxide production and TNF-α release following IFN-γ activation.
MIF appears to act through receptors CD74 and CD44, likely in a trimeric form. Human MIF is active on mouse cells and shows high amino acid identity with MIF from other species: 90% identical to mouse MIF, 94% to bovine MIF, 95% to porcine MIF, and 90% to rat MIF. |
