Mannose-containing receptors

Polythiophenes functionalized with monosaccharides have been evaluated for their ability to detect the influenza virus and E. coli (Baek et al. 2000). Copolymers of thiophene acetic acid 10 and carbohydrate-modified thiophenes 11 have been prepared via iron(III) chloride mediated polymerization. Addition of influenza virus to a sialic acid containing copolymer resulted in a blue shift of the polymer absorption maximum, resulting in an orange to red chromatic transition. Mannose-containing polythiophenes underwent color changes upon the addition of the lectin ConA or E. coli cells that contain cell surface mannose-binding receptors. A similar biotinylated pol5hhiophene afforded a streptavidin responsive material (Paid and Leclerc 1996). 

Recently another signal, the phenylalanine-tryptophan motif (or the motif containing two aromatic residues, such as (F/Y)X(F/Y), in yeast), was shown to direct some proteins including cation-dependent mannose 6-phosphate receptor (see Section IIIJ,2) from endosomes to the TGN (Schweizer et al., 1997 Burd et al., 1998). Most probably, it is used for the (retrograde) recycling processes. A putative coat complex was also discovered and named retromer (Seaman et al., 1998). 

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