Cytokines of the IL6/GCSF/MGF family are glycoproteins of about 170 to 180 amino acid residues that contain four conserved cysteine residues involved in two disulphide bonds. They have a compact, globular fold (similar to other interleukins), stabilized by the 2 disulphide bonds. One half of the structure is dominated by a 4 alpha-helix bundle with a left-handed twist: the helices are anti-parallel, with 2 overhand connections, which fall into a 2-stranded anti-parallel beta-sheet. The fourth alpha helix is important to the biological activity of the molecule. Interleukin (IL)-6 is an important proinflammatory and immunoregulatory cytokine expressed by various cells. Interleukin-6 has been shown to inhibit the growth of early stage and to promote the proliferation of advanced stage melanoma cells in vitro.
Recombinant Human IL-6 produced in E. coli is a single, non-glycosylated polypeptide chain containing 184 amino acids and having a molecular mass of 21000 Dalton.
rHuIL-6 is fully biologically active when compared to standard. The ED50 as determined by the dose-dependant stimulation of murine 7TD1 cells is less then 0.1 ng/ml, corresponding to a Specific Activity of 5 x 107 IU/mg.
Greater than 98.0% as determined by:
(a) Analysis by RP-HPLC.
(b) Anion-exchange FPLC.
(c) Analysis by reducing and non-reducing SDS-PAGE Silver Stained gel.
21 KD+/-10% determined by reduced SDS-PAGE
The sequence of the first five N-terminal amino acids was determined and was found to be Ser-Pro-Val-Pro-Pro.
Less than 0.3ng/μg (0.3IEU/μg) determined by LAL test
Lyophilized from a concentrated (1mg/ml) solution in water containing 43μg/ml sodium chloride and 50μg/ml HSA
Lyophilized rHuIL-6 although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution rHuIL-6 should be stored at 4oC between 2-7 days and for future use below -18°C. For long-term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please avoid freeze-thaw cycles.
It is recommended to reconstitute the lyophilized rHuIL-6 in sterile 18M¦¸-cm H2O not less than 100μg/ml, which can then be further diluted to other aqueous solutions.