The Contribution of Vibrational Entropy to Molecular Association : The Dimerization of Insulin Export

@article{citeulike:804399, abstract = {The association reaction of two molecules to form a single complex must overcome a large entropic barrier due to the loss of translation and rotational degree of freedom; estimates of the T[Delta]S term are of the order of 30 kcal/mol for proteins. The approach of Chandler and Pratt is used to provide a statistical mechanical formulation for the connection between the gas-phase and solution binding free energies. This make possible a clear separation of the vibrational contribution to the gas-phase binding enthalpy and entropy from the solvation terms. Further, it suggests that the calculated gas-phase result, should be a good approximation in solution for many systems. To illustrate the formulation, a harmonic dynamics model is used to study the dimerization of insulin. The vibrational entropy increase in the dimer complex, relative to the two separate monomers, is 23 entropy units. This contributes ?7[middle dot]2 kcal/mol to the dimerization free energy. It is not possible to identify a small number of specific dimer modes that give rise to this entropy contribution. Instead, small alterations in the frequencies of many modes below 400 to 600 cm-1 are found to contribute. The relative importance of vibrational and other effects in macromolecule?macromolecule and macromolecule?small molecule associations is discussed.}, author = {Tidor, Bruce and Karplus, Martin}, citeulike-article-id = {804399}, citeulike-linkout-0 = {http://dx.doi.org/10.1006/jmbi.1994.1300}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/8176732}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=8176732}, citeulike-linkout-3 = {http://www.sciencedirect.com/science/article/B6WK7-45PV5VG-BR/2/64e1b1b03b2f672a46a9855657b482d8}, day = {5}, doi = {10.1006/jmbi.1994.1300}, journal = {Journal of Molecular Biology}, keywords = {nma, protein\_dynamics}, month = {May}, number = {3}, pages = {405--414}, posted-at = {2006-08-17 19:35:30}, priority = {2}, title = {The Contribution of Vibrational Entropy to Molecular Association : The Dimerization of Insulin}, url = {http://dx.doi.org/10.1006/jmbi.1994.1300}, volume = {238}, year = {1994} }

TY - JOUR ID - citeulike:804399 L3 - citeulike-article-id:804399 N2 - The association reaction of two molecules to form a single complex must overcome a large entropic barrier due to the loss of translation and rotational degree of freedom; estimates of the T[Delta]S term are of the order of 30 kcal/mol for proteins. The approach of Chandler and Pratt is used to provide a statistical mechanical formulation for the connection between the gas-phase and solution binding free energies. This make possible a clear separation of the vibrational contribution to the gas-phase binding enthalpy and entropy from the solvation terms. Further, it suggests that the calculated gas-phase result, should be a good approximation in solution for many systems. To illustrate the formulation, a harmonic dynamics model is used to study the dimerization of insulin. The vibrational entropy increase in the dimer complex, relative to the two separate monomers, is 23 entropy units. This contributes ?7[middle dot]2 kcal/mol to the dimerization free energy. It is not possible to identify a small number of specific dimer modes that give rise to this entropy contribution. Instead, small alterations in the frequencies of many modes below 400 to 600 cm-1 are found to contribute. The relative importance of vibrational and other effects in macromolecule?macromolecule and macromolecule?small molecule associations is discussed. IS - 3 JF - Journal of Molecular Biology EP - 414 TI - The Contribution of Vibrational Entropy to Molecular Association : The Dimerization of Insulin VL - 238 SP - 405 KW - nma KW - protein_dynamics AU - Tidor, Bruce AU - Karplus, Martin PY - 1994/05/05/ UR - http://dx.doi.org/10.1006/jmbi.1994.1300 ER -