Alpha-C-mannosyltryptophan is not recognized by conventional mannose-binding lectins.
Alpha-C-mannosyltryptophan (C-Man-Trp) is a novel, naturally occurring C-linked carbohydrate-protein linkage first found in 1994 from human ribonuclease 2. Since then, a number of C-Man-Trp residue have been found from several important proteins such as interleukin 12 beta, components of complement system, thrombospondin-1, and erythropoietin receptor, however, the biological functions have remained unknown even though its biosynthetic pathway has been revealed. In order to find a clue as to the biological functions, we examined the affinity of C-Man-Trp with conventional mannose lectin such as concanavarin A (Con A) and mannose-binding lectin (MBL). The affinity of C-Man-Trp with Con A, a typical mannose-binding lectin from plant was examined using a Con A-Sepharose column. Unlike p-nitrophenyl-alpha-O-Man, C-Man-Trp was not retained on the column. MBL-C, a major mannose-binding lectin purified from mouse serum, did not bind with N-biotinylated C-Man-Trp, judging from ELISA based assay. These results imply that C-Man-Trp may be recognized with the other specific proteins associated with its unknown biological functions.
Nishikawa
Toshio
T
Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan. nishikawa@agr.nagoya-u.ac.jp
Kajii
Shigeo
S
Sato
Chihiro
C
Yasukawa
Zenta
Z
Kitajima
Ken
K
Isobe
Minoru
M
D015153:Blotting, Western; D002846:Chromatography, Affinity; D037601:Mannose-Binding Lectin / Q000378:metabolism*; D011485:Protein Binding; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000378:metabolism*
C101500:C(2)-mannosyltryptophan; D037601:Mannose-Binding Lectin; D014364:Tryptophan