Synthesis of the glycosylated polypeptide chain of an inducible costimulator on T-cells.
The glycoprotein AILIM/ICOS (Activation inducible lymphocyte immunomediately molecule/Inducible co-stimulator) on T-cells was identified in 1998 as a member of the CD28/CTLA4 family. The three-dimensional structure of the AILIM/ICOS extracellular domain has not been solved, and therefore we have examined the preparation of homogeneous glycosylated polypeptide chains of this domain having two homogeneous N-linked complex type oligosaccharides for use in folding experiments. To synthesize the glycosylated whole polypeptide chain of the AILIM/ICOS extracellular domain, the target polypeptide chain was divided into four segments, each containing a cysteine residue. Those peptide segments were synthesized by conventional SPPS, followed by thioesterification of the C-terminus. The oligosaccharide moiety, a biantennary complex type disialyloligosaccharide, was attached to the cysteine thiol in the peptide backbone using the haloacetamide method. These peptides, as well as a glycosylated peptide, were sequentially coupled by use of native chemical ligation. This process successfully afforded the desired polypeptide chain having homogeneous oligosaccharides.
Murase
Takefumi
T
International Graduate School of Arts and Sciences, Yokohama City University, 22-2, Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan.
Kajihara
Yasuhiro
Y
D000595:Amino Acid Sequence; D000945:Antigens, Differentiation, T-Lymphocyte / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006031:Glycosylation; D060889:Inducible T-Cell Co-Stimulator Protein; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry*; D017510:Protein Folding
D000945:Antigens, Differentiation, T-Lymphocyte; D060889:Inducible T-Cell Co-Stimulator Protein; D010455:Peptides