Does glycosylation affect cytokine stability?
This question of cytokine stability is of prime importance. Kodama and colleagues have examined the impact of O-linked sugar chains on recombinant human interleukin 5 (rh IL-5) produced by Chinese hamster ovary (CH0) cells using high-performance anion-exchange chromatography in high pH conditions [1]. Sugar chains were digested using various glycosidases and 3 subsets of rh IL-5 were studied: intact rh IL-5, deglycosylated rh IL-5 on the O-site (de-O-glycosylated) and on the N-site (de-N-glycosylated). The authors found that intact rh IL-5 and de-O-glycosylated rh IL-5 produced similar activity when incubated at 70° C for 30 min, while the activity of the de-N-glycosylated rh IL-5 decreased significantly. The authors thus concluded that N-linked sugar chains contribute to the thermostability of rh IL-5. Regarding interferons (IFNs), Karpusas and colleagues have recently provided experimental evidence which shows that glycosylation of human INF-beta is a determinant factor for the solub
