Molecular recognition XIII. The binding of the H-type 2 human blood group determinant by a winged bean (Psophocarpus tetragonolobus) acidic lectin

Abstract

The winged bean acidic lectin (WBA 11) binds the H-type 2 human blood group related trisaccharide (a-L-Fuc-(lc + 2b)-P-D-Gal-(1 b + 4a)-P-D-GlcNAc-OMe, 1). Interactions that importantly contribute to the specificity of the complex formation are provided by CH2-6b, OH-4b, OH-3b, and OH-2c of 1. On the basis of the relative activities of the monodeoxy and mono-0-methyl derivatives of 1, the hydroxyl groups at the 3a, 6a, and 4c positions become located at the periphery of the combining site, whereas the CH30-la, NHAc-2a, and CH3-5c groups are more remote from the protein surface and fully exposed to bulk water. Whereas the WBA I1 lectin marginally recognizes the H- (24) is bound 3.4 times more strongly than 1. This and other results, which are related to changes in interaction between the ligand and the apron of the combining site, are attributed to changes in hydration that lead to enthalpy~ntropy compensation. In certain cases, the interactions are found to stabilize the complex. [Traduit par la rCdaction]

Sulfonamide Drugs Binding to the Colchicine Site of Tubulin: Thermodynamic Analysis of the Drug−Tubulin Interactions by Isothermal Titration Calorimetry

“…[22][23][24][25][26] A linear relationship of ∆H with T∆S with slope exactly equal to one is an indication of complete compensation. Generally, enthalpy-entropy compensation occurs in any system with ∆C p not equal to zero 27 Figure 5A and Figure 5B show enthalpy-entropy compensation plots depicting the variation of ∆H as a function of T∆S for drug 2 and for drug 5, respectively.…”

A predominantly hydrophobic recognition of H‐antigenic sugars by winged bean acidic lectin: a thermodynamic study

“…In addition, the contribution of hydrophobic interactions to the binding process can be determined by replacement of the OH by an apolar substituent, such as an oMe group [21]. Earlier, our group reported the thermodynamics of binding of some deoxy congeners, by their ability to inhibit binding of the fluorescent reporter ligand, N ‐dansylgalactosylamine [22]. The binding constants were calculated by competition between the fluorescent and the deoxy sugars for interaction with the lectin.…”

Thermodynamics of Monosaccharide and Disaccharide Binding to Lectin

“…Observation of enthalpy-entropy compensation is not surprising as thermodynamic studies on several lectins strongly emphasize the importance of water as a mediator in proteincarbohydrate recognition (Lemieux et al, 1994;Puri and Surolia, 1994;Toone, 1994;Ramkumar et al, 1995). This fact is also succinctly brought out by the high resolution structural analysis of Lathyrus ochrus lectin I complexed with its complementary oligosaccharide ligand (Bourne et al, 1992).…”