Open AccessBinding of Manno ‐oligosaccharides to Concanavalin A
Author(s) -
LANDSCHOOT Anita,
LOONTIENS Frank G.,
BRUYNE Clement K.
Publication year - 1980
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1980.tb04316.x
Subject(s) - titration , concanavalin a , oligosaccharide , chemistry , residue (chemistry) , binding constant , stereochemistry , binding site , carbohydrate , biochemistry , in vitro
The association constants for binding of methyl α‐ d ‐mannopyranoside (I), mannobiose (II) and mannotriose (III) to concanavalin A were determined in the temperature range 285–313 K by a substitution titration, using 4‐methylumbelliferyl α‐ d ‐mannopyranoside as a carbohydrate‐specific and fluorescent indicator. All binding equilibria are simple, but establish extremely slowly with II and III. At 298.3 K, K increases moderately from I to III: (6.4 ± 0.5) × 10 3 , (1.2 ± 0.1) × 10 4 and (1.10 ± 0.05) × 10 5 M −1 . For binding of I, II and III, the –Δ H ° values are constant (36 ± 2 kJ mol −1 ) and equal to the average value (36.1 ± 0.6 kJ mol −1 ) obtained for the three corresponding 4‐methylumbelliferyl α‐ d ‐manno‐oligosaccharides [Van Landschoot, A., Loontiens, F. G., and De Bruyne, C. K. (1978) Eur. J. Biochem. 83 , 277–285]. The data are interpreted as arising from specific binding to a single mannopyranosyl residue in (α 1 → 2)‐linked manno‐oligosaccharides.