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Recombinant human interleukin-12 is the second example of a C-mannosylated protein.
- Source :
- Glycobiology; May 1999, Vol. 9 Issue: 5 p435-441, 7p
- Publication Year :
- 1999
-
Abstract
- The beta-chain of human interleukin 12 (IL-12) contains at position 319-322, the sequence Trp-x-x-Trp. In human RNase 2 this is the recognition motif for a new, recently discovered posttranslational modification, i.e., the C-glycosidic attachment of a mannosyl residue to the side chain of tryptophan. Analysis of C-terminal peptides of recombinant IL-12 (rHuIL-12) by mass spectrometry and NMR spectroscopy revealed that Trp-319beta is (partially) C-mannosylated. This finding was extended by in vitro mannosylation experiments, using a synthetic peptide derived from the same region of the protein as an acceptor. Furthermore, human B-lymphoblastoid cells, which secrete IL-12, were found to contain an enzyme that carries out the C-mannosylation reaction. This shows that nonrecombinant IL-12 is potentially C-mannosylated as well. This is only the second report on a C-mannosylated protein. However, the occurrence of the C-mannosyltransferase activity in a variety of cells and tissues, and the presence of the recognition motif in many proteins indicate that more C-mannosylated proteins may be found.
Details
- Language :
- English
- ISSN :
- 09596658 and 14602423
- Volume :
- 9
- Issue :
- 5
- Database :
- Supplemental Index
- Journal :
- Glycobiology
- Publication Type :
- Periodical
- Accession number :
- ejs35842516
- Full Text :
- https://doi.org/10.1093/glycob/9.5.435