Glycosylation and epitope mapping of the 5T4 glycoprotein oncofoetal antigen.
AuthorsShaw, David M
Woods, Andrew M
Myers, Kevin A
Davies, Michael J
Renouf, David V
Hounsell, Elizabeth F
Stern, Peter L
AffiliationCRC Immunology Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Manchester M20 4BX, UK.
MetadataShow full item record
AbstractThe human 5T4 oncofoetal antigen is a focus for development of several antibody-directed therapies on the basis of the murine monoclonal antibody against 5T4 (mAb5T4), which recognizes a conformational epitope. 5T4 molecules are highly N-glycosylated transmembrane glycoproteins whose extracellular domain contains two regions of leucine-rich repeats (LRRs) and associated flanking regions, separated by an intervening hydrophilic sequence. Using a series of deletion and mutated cDNA constructs as well as chimaeras with the murine homologue, we have mapped the mAb5T4 epitope to the more membrane-proximal LRR2 or its flanking region. Analysis of the glycosylation of the seven consensus Asp-Xaa-Ser/Thr sites was consistent with all of the sites being glycosylated. A combination of two high-mannose chains (predominantly octasaccharide) and five mostly sialylated bi-, tri- and tetra-antennary complex chains with minor quantities of core fucose were detected. The two glycosylation sites, which are the most likely to have predominantly high-mannose chains, are in the only two regions that show significant differences between the human and the 81% identical mouse sequence. A site-directed mutation, which abolished glycosylation at one of these sites (position 192), did not alter antigenicity. The other, which is nearest to the N-terminus in the human, has an Asn-Leu-Thr to Asn-Leu-Leu conversion in the mouse, so cannot be glycosylated in the latter species. The large complex glycosylation at the other sites is likely to influence the antigenicity and tertiary structure generating the 5T4 epitope.
CitationGlycosylation and epitope mapping of the 5T4 glycoprotein oncofoetal antigen. 2002, 363 (Pt 1):137-45 Biochem. J.
JournalThe Biochemical Journal
- Characterization of the murine 5T4 oncofoetal antigen: a target for immunotherapy in cancer.
- Authors: Woods AM, Wang WW, Shaw DM, Ward CM, Carroll MW, Rees BR, Stern PL
- Issue date: 2002 Aug 15
- Isolation of a high affinity scFv from a monoclonal antibody recognising the oncofoetal antigen 5T4.
- Authors: Shaw DM, Embleton MJ, Westwater C, Ryan MG, Myers KA, Kingsman SM, Carroll MW, Stern PL
- Issue date: 2000 Dec 15
- Regulation of N-linked core glycosylation: use of a site-directed mutagenesis approach to identify Asn-Xaa-Ser/Thr sequons that are poor oligosaccharide acceptors.
- Authors: Kasturi L, Chen H, Shakin-Eshleman SH
- Issue date: 1997 Apr 15
- Organisation of the mouse and human 5T4 oncofoetal leucine-rich glycoprotein genes and expression in foetal and adult murine tissues.
- Authors: King KW, Sheppard FC, Westwater C, Stern PL, Myers KA
- Issue date: 1999 Jun 9
- Exchange of Ser-4 for Val, Leu or Asn in the sequon Asn-Ala-Ser does not prevent N-glycosylation of the cell surface glycoprotein from Halobacterium halobium.
- Authors: Zeitler R, Hochmuth E, Deutzmann R, Sumper M
- Issue date: 1998 Dec