Temperature-induced ultraviolet difference absorption spectrometry for determination of enthalpy changes. Binding of 4-methylumbelliferyl glycosides to four lectins.
Raising the temperature in a single mixture of a lectin and a chromophoric glycoside allows determination of the binding enthalpy. This is made possible by continuously monitoring the displacement of the complex from its equilibrium concentration with a sensitive difference absorption spectrophotometer. The method is illustrated with the following lectins: concanavalin A, soybean agglutinin, peanut agglutinin and Erythrina cristagalli agglutinin. The ligands are 4-methylumbelliferyl glycosides. The binding enthalpies found range from -60 kJ X mol-1 for the Gal beta 1----3GalNAc-beta glycoside and peanut agglutinin to -30 kJ X mol-1 for a monosaccharide glycoside and the other lectins.
D006027:Glycosides; D006923:Hymecromone / Q000031:analogs & derivatives; D037102:Lectins; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship; D013816:Thermodynamics
C030561:4-methylumbelliferyl glycosides; D006027:Glycosides; D037102:Lectins; D006923:Hymecromone