Recombinant Mouse MIF, Tag Free

MIF (or macrophage migration inhibitory factor) was the first lymphokine/cytokine to be recognized in the pregenomics era ^{[1, 2]}. Regardless, it is one of the least understood of all inflammatory mediators ^{[1, 3]}. Mouse MIF is a 12.5 kDa, 115 amino acid (aa) nonglycosylated polypeptide that is synthesized without a signal sequence ^[4-7]. Secretion occurs nonclassically via an ABCA1 transporter ^[6]. The initiating Met is removed, leaving Pro as the first amino acid. The molecule consists of two alpha -helices and six beta -strands, four of which form a beta -sheet. The two remaining beta -strands interact with other MIF molecules, creating a trimer ^{[2, 8]}. Structure-function studies suggests MIF is bifunctional with segregated topology. The N- and C-termini mediate enzyme activity (in theory). Phenylpyruvate tautomerase activity (enol- to-keto) has been demonstrated and is dependent upon Pro at position #1 ^[9]. Amino acids 3-23 have also been shown to be reminescent of a GST glutathione-binding domain ^[10]. MIF has proinflammatory cytokine activity centered on aa’s 49-65. On fibroblasts, MIF induces, IL-1, IL-8 and MMP expression; on macrophages, MIF stimulates, NO production and TNF-alpha release following IFN-gamma activation ^{[11, 12]}. Mouse MIF apparently acts through CD74 and CD44, likely in some form of trimeric interaction ^{[13, 14]}. Mouse MIF is active on human cells, while human MIF is active on mouse cells ^[12]. Mouse MIF is 99%, 84%, 90%, and 90% aa identical to rat, porcine, bovine and human MIF, respectively. 

Reference

[1].Norand, E.F. and M. Leech (2005) Front. Biosci. 10:12.

[2]. Donn, R.P. and D.W. Ray (2004) J. Endocrinol. 182:1.

[3]. Calandra, T. and T. Roger (2003) Nat. Rev. Immunol. 3:791.

[4]. Bozza, M. et al. (1995) Genomics 27:412.

[5]. Mitchell, R. et al. (1995) J. Immunol. 154:3863.

[6]. Flieger, O. et al. (2003) FEBS Lett. 551:78.

[7]. Lanahan, A. et al. (1992) Mol. Cell. Biol. 12:3919.

[8]. Philo, J.S. et al. (2004) Biophys. Chem. 108:77.

[9]. Stamps, S.L. et al. (2000) Biochemistry 39:9671.

[10]. Blocki, F.A. et al. (1993) Protein Sci. 2:2095.

[11]. Sato, A. et al. (2003) Dev. Comp. Immunol. 27:401.

[12]. Bernhagen, J. et al. (1994) Biochemistry 33:14144.

[13]. Leng, L. et al. (2003) J. Exp. Med. 197:1467.

[14]. Meyer-Siegler, K.L. and P.L. Vera (2005) J. Urology 173:615.