Abstract:
Interferon-beta (IFNβ) is a cytokine involved in the antiviral, anti-proliferative and
immunomodulatory responses of cells, and a potent drug for multiple sclerosis.
Human interferon beta (HuIFNβ) gene fused with the glucoamylase signal sequence
in the N-terminus and 6 His Tag in the C-terminus was cloned into pKlac1 vector
and introduced in Kluyveromyces lactis to allow secreted expression and one-step
purification of the protein. Recombinant yeast transformant with the highest level
ofHuIFNβ production was identified, and this secreted up to 1 mg/L of the cytokine
after 72 h of incubation. Glycosylated and non-glycosylated forms of the cytokine
were elaborated by the yeast, the latter in higher quantities. His tag of the protein
allowed easy one-step purification by nickel-nitriloacetic acid affinity chromatography,
yielding close to 100% purity. SDS-PAGE, western blot andMALDI-TOF-TOF
confirmed the identity of the protein. The biological activity of the recombinant
HuIFNβ was confirmed by its anti cell proliferative activity on HeLa cells. Expression
ofHuIFNβ in K. lactis is advantageous since it is a very safe organism to produce
proteins for therapeutic applications, allows glycosylation and offers a cost effective
method for large scale production as it can be grown in cheap carbon sources
