Title : Structures of the major carbohydrates of natural human
interleukin-2
Abstract :
- Purified human interleukin-2 secreted by peripheral blood lymphocytes from healthy donors was found to exist in several forms
- These forms were (partially) resolved by reversed-phase high-performance liquid chromatography and sodium dodecyl sulfate/polyacrylamide gel electrophoresis
- Two major polypeptide species ( interleukin-2 N1 and N2, 16.5 kDa) were shown to be glycosylated on the basis of [3H]galactose/[3H]glucosamine incorporation and determination of amino sugars after acid hydrolysis
- A third component ( interleukin-2 M , 14.5 kDa) represents a nonglycosylated form
- The amino acid com position and the NH2-terminal sequence of both forms are consistent with the data deduced from the cDNA coding for interleukin-2 after removal of a leader peptide of 20 amino acids
- Carbohydrates are O-linked to the IL-2 protein via threonine-3 of the polypeptide chain
- The oligosaccharides were released by reductive beta-elimination and were purified by gel filtration and high-performance liquid chromatography
- Applying methylation analysis, exoglycosidase digestion and fast atom bombardment mass spectrometry the following major carbohydrate structures were identified: N1, NeuAc(alpha 2-3)Gal(beta 1-3)GalNAc-ol; and N2, NeuAc(alpha 2-3)Gal(beta 1-3)[NeuAc(alpha 2-6)]GalNAc-ol
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. interleukin-2, , interleukin-2, the major carbohydrates, -
- 6. O-linked, , IL-2 protein, Carbohydrates, threonine-3
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):
- 6. IL-2 protein, Carbohydrates, threonine-3