Abstract
Prespore-specific antigen (PsA) is a putative cell-adhesion molecule of the cellular slime mould Dictyostelium discoideum, which has a similar molecular architecture to several mammalian cell-surface proteins. It has an N-terminal globular domain presented to the extracellular environment on an O-glycosylated stem (glycopeptide) that is attached to the cell membrane through a glycosyl-PtdIns anchor. The sequence of PsA suggests that PsA may belong to a new family of cell-surface molecules and here we present information on the structure of the N-terminal globular domain and determine the reducing-terminal linkage of the O-glycosylation. To obtain a sufficient amount of pure protein, a secreted recombinant form of PsA (rPsA), was expressed in D. discoideum and characterised. 1H-NMR spectra of rPsA contained features consistent with a high degree of β-sheet in the N-terminal globular domain, a feature commonly observed in cell-adhesion proteins. Solid-phase Edman degradation of the glycopeptide of rPsA indicated that 14 of the 15 threonines and serines in the spacer region were glycosylated. The chemical structures of the O-glycosylations were determined to be single N-acetylglucosamine residues.
Original language | English (US) |
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Pages (from-to) | 511-518 |
Number of pages | 8 |
Journal | European Journal of Biochemistry |
Volume | 238 |
Issue number | 2 |
DOIs | |
State | Published - 1996 |
Externally published | Yes |
Keywords
- Cell-surface glycoproteins
- Dictyostelium discoideum
- N-acetylglucosamine
- O-glycosylation
ASJC Scopus subject areas
- Biochemistry