Title : Disulfide assignments in recombinant mouse and human
interleukin 4
Abstract :
- The disulfide pairings of mouse and human interleukin 4 ( IL-4 ) proteins have been determined
- The purified proteins , synthesized by recombinant DNA technology, are fully active as judged by their ability to stimulate an appropriate biological response in a variety of functional assays
- Peptide maps were produced by digesting the proteins with pepsin and separating the resulting fragments by reverse-phase HPLC using linear acetonitrile-TFA gradients
- Cystine-containing peptides were identified by determining which reverse-phase peaks showed an altered elution pattern after reduction
- These peptides were purified further and defined by com position and sequence analysis
- Three sets of disulfide-linked peptides were consistently identified for each protein
- For mouse IL-4 , the first and fifth, second and fourth, and third and sixth cysteines are joined
- The disulfide bonds in human IL-4 are between the first and sixth, second and fourth, and third and fifth cysteines
- A large double-loop region within the central three-fifths of each protein is stabilized by these bonds
- Sequence analysis of the peptides containing the third and fifth cysteines of human IL-4 also demonstrated that only one of the potential N-glycosylation sites is used by C127 mammary tumor cells
- Complete alkylation of mouse IL-4 under mild conditions completely destroyed its biological activity in a hematopoietic precursor cell proliferation assay
Output (sent_index, trigger,
protein,
sugar,
site):
- 10. N-glycosylation, , -, -, sites
- 10. used, , -, -, sites
Output(Part-Of) (sent_index,
protein,
site):
- 10. -, cysteines
- 10. IL-4, cysteines
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):