ISSN:
1573-4994
Keywords:
Lens culinaris agglutinin–glycoprotein complex
;
carbohydrate moiety
;
α-L-fucose
;
lactotransferrin
;
serotransferrin
;
fluorescein
;
fluorescence intensity quenching
;
time-resolved anisotropy decay
;
protein dynamics
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Interaction between the fluorescent Lens culinaris agglutinin–fluorescein complex (LCA-FITC) and two glycoproteins, lactotransferrin (LTF) and serotransferrin (STF), was studied. The two glycoproteins have the same glycan structures, with one difference: the lactotransferrin glycans contain a fucose residue α-1,6-linked to the N-acetylglucosamine residue involved in the N-glycosylamine linkage. Fluorescence intensity quenching of the LCA-FITC complex shows that affinity between LCA and lactotransferrin is 50 times higher than that between LCA and serotransferrin, the fucose playing a major role in this high affinity (K a is equal to 9.66 and 0.188 μM −1 for the LCA–LTF complex and LCA–STF complex, respectively). Time-resolved anisotropy decay indicates that the rotational correlation time of LCA (20 ns) does not change to a large extent whether the glycoproteins are bound to LCA or not. This suggests that there is no extended physical contact between LCA and the glycoproteins. The interaction between LCA and the glycoproteins occurs likely only via the carbohydrate chains, the STF and the LTF rotating almost-freely in the vicinity of LCA, with the glycans as an anchor.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022577925966
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