L-fucose α1→6 specific lectin
Disclosed is a novel lectin which can bind specifically to an L-fucose α1→6 sugar chain. Also disclosed is use of the lectin. The L-fucose α1→6 specific lectin of the present invention is characterized in that: (1) the lectin is extracted from a basidiomycete or an ascomycete; (2) the lectin has a molecular weight by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of 4,000 to 40,000; and (3) the lectin has an affinity to an L-fucose α1→6 sugar chain, the affinity being represented by an association constant of 1.0×10 4 M −1 or more (at 25 degrees C.). The lectin can be used for detecting an L-fucose α1→6 sugar chain specifically, and is effective for the purification of an L-fucose α1→6 sugar chain or a non L-fucose α1→6 sugar chain.
1. An L-fucose α1→6 specific lectin that:
(1) is extracted from basidiomycete or ascomycete,
(2) has a molecular weight by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of 4,000 to 40,000,
(3) has an affinity to an L-fucose α1→6 sugar chain, the affinity being represented by an association constant of 1.0×10 4 M −1 or more (at 25 degrees C.), and
(4) has an association constant of 1.0×10 3 M −1 or less (at 25 degrees C.) for a high mannose sugar chain and/or a glycolipid not including the fucose α1→6 sugar chain.
2. The L-fucose α1→6 specific lectin according to claim 1 , wherein the L-fucose α1→6 sugar chain has sialic acid at the nonreducing terminus.
3. The L-fucose α1→6 specific lectin according to claim 1 , wherein the L-fucose α1→6 specific lectin (5) has an affinity to L-fucose α1→6 mono-, di-, tri-, tetra-antennary N-glycan(s), the affinity being represented by an association constant of 1.0×10 4 M −1 or more (at 25 degrees C.).
4. The L-fucose α1→6 specific lectin according to claim 1 , wherein the basidiomycete belongs to Strophariaceae, Tricholomataceae, Amanitaceae, or Polyporaceae.
5. The L-fucose α1→6 specific lectin according to claim 1 , wherein the basidiomycete is Pholiota terrestris, Pholiota squarrosa, Pholiota adiposa, Stropharia rugosoannulata, Naematoloma sublateritium, Lepista sordida , or Amanita muscaria.
6. The L-fucose α1→6 specific lectin according to claim 1 , wherein the L-fucose α1→6 specific lectin further (6) includes an amino acid sequence shown in SEQ ID No. 1.
7. An L-fucose α1→6 specific lectin that is
protein or peptide consisting of an amino acid sequence shown in any of SEQ ID Nos. 2 to 6.
8. A method of manufacturing an L-fucose α1→6 specific lectin, comprising the steps of:
subjecting an aqueous solvent extract of basidiomycete and/or ascomycete to any of following chromatography:
(i) hydrophobic chromatography and reversed-phase chromatography,
(ii) affinity chromatography, and
(iii) ion-exchange chromatography and gel filtration; and
obtaining lectin having:
(vi) a molecular weight by SDS-PAGE of 4,000 to 40,000,
(v) an affinity represented by an association constant to an L-fucose α1→6 sugar chain of 1.0×10 4 M −1 or more, and
(vi) an affinity represented by an association constant of 1.0×10 3 M −1 or less (at 25 degrees C.) for a high mannose sugar chain and/or a glycolipid which does not contain a fucose α1→6 sugar chain.
9. The method of manufacturing the L-fucose α1→6 specific lectin according to claim 8 , wherein the basidiomycete is selected from at least one of Strophariaceae, Tricholomataceae, Amanitaceae, and Polyporaceae.
10. The method of manufacturing the L-fucose α1→6 specific lectin according to claim 8 , wherein the basidiomycete is at least one selected from Pholiota terrestris, Pholiota squarrosa, Pholiota adiposa, Stropharia rugosoannulata, Naematoloma sublateritium, Lepista sordida , and Amanita muscaria.
11. The method of manufacturing the L-fucose α1→6 specific lectin according to claim 8 , wherein carpophores (Fruiting bodies) of the basidiomycete and/or ascomycete are used.
12. A method of detecting an L-fucose α1→6 sugar chain, comprising a step of causing a sugar chain to act on the L-fucose α1→6 specific lectin according to claim 1 .
13. The method of detecting an L-fucose α1→6 sugar chain according to claim 12 , wherein the sugar chain is a tumor marker.
14. A method of fractionating an L-fucose α1→6 sugar chain, comprising a step of causing a sugar chain to act on the L-fucose α1→6 specific lectin according to claim 1 .
15. The method of fractionating an L-fucose α1→6 sugar chain according to claim 14 , wherein the sugar chain is bound to an antibody.
16. A diagnostic agent or diagnostic agent kit for detecting an L-fucose α1→6 sugar chain, wherein the diagnostic agent includes the L-fucose α1→6 specific lectin according to claim 1 as an active ingredient.