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Biochemistry

Title:		"Thermodynamic analysis of binding between mouse major urinary protein-I and the pheromone 2-sec-butyl-4,5-dihydrothiazole"
Author(s):		Sharrow SD; Novotny MV; Stone MJ;
Address:		"Department of Chemistry and Institute for Pheromone Research, Indiana University, Bloomington 47405-0001, USA"
Journal Title:		Biochemistry
Year:		2003
Volume:		42
Issue:		20
Page Number:		6302 - 6309
DOI:		10.1021/bi026423q
ISSN/ISBN:		0006-2960 (Print) 0006-2960 (Linking)
Abstract:		"The mouse pheromone 2-sec-butyl-4,5-dihydrothiazole (SBT) binds to an occluded, nonpolar cavity in the mouse major urinary protein-I (MUP-I). The thermodynamics of this interaction have been characterized using isothermal titration calorimetry (ITC). MUP-I-SBT binding is accompanied by a large favorable enthalpy change (DeltaH = -11.2 kcal/mol at 25 degrees C), an unfavorable entropy change (-TDeltaS = 2.8 kcal/mol at 25 degrees C), and a negative heat capacity change [DeltaC(p)() = -165 cal/(mol K)]. Thermodynamic analysis of binding between MUP-I and several 2-alkyl-4,5-dihydrothiazole ligands indicated that the alkyl chain contributes more favorably to the enthalpy and less favorably to the entropy of binding than would be expected on the basis of the hydrophobic desolvation of short-chain alcohols. However, solvent transfer experiments indicated that desolvation of SBT is accompanied by a net unfavorable change in enthalpy (DeltaH = +1.0 kcal/mol) and favorable change in entropy (-TDeltaS = -1.8 kcal/mol). These results are discussed in terms of the possible physical origins of the binding thermodynamics, including (1) hydrophobic desolvation of both the protein and the ligand, (2) formation of a buried water-mediated hydrogen bond network between the protein and ligand, (3) formation of strong van der Waals interactions, and (4) changes in the structure, dynamics, and/or hydration of the protein upon binding"
Keywords:		"Animals Binding Sites Buffers Hydrogen Bonding In Vitro Techniques Mice Models, Molecular Molecular Structure Pheromones/*chemistry/*metabolism Proteins/*chemistry/*metabolism Recombinant Proteins/chemistry/metabolism Thermodynamics Thiazoles/*chemistry/*;"
Notes:		"MedlineSharrow, Scott D Novotny, Milos V Stone, Martin J eng DC 02418/DC/NIDCD NIH HHS/ Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 2003/05/21 Biochemistry. 2003 May 27; 42(20):6302-9. doi: 10.1021/bi026423q"