Conformational energy, change

Figure 6.7 Conformational energy changes during rotation around the 2,3 bond of butane.

The chain conformational energy change is given by the following expression ... 

In staurosporine (170), a benzodipyrrole derivative having protein kinase C activity (see Section 7.21.12), the conformational energy changes with protonation have been determined by NMR methods <91CC182>. 

The consideration of a sufficient degree of protein flexibility needs to become part of standard docking approaches. This will require faster algorithms. In addition, with respect to scoring, an often overlooked aspect of this problem is that as soon as receptor flexibility is allowed, protein conformational energy changes need to be accounted for appropriately. 

Cyclic polymers are unable to form tails and hence the conformational energy change on adsorption is less for the cyclic polymer at low relative molecular masses when the surface concentration is small. As the relative molecular mass increases, cyclics form larger loops that reduce the entropy change on adsorption whereas in the linear polymer the contribution of the tails to the entropy change becomes diluted at higher relative molecular masses. Figure 5.17 shows the volume fraction profiles calculated from self-consistent field theory, with the separate contributions from loops and tails. 

The expressions appearing in the exponents are the free energy change of the NA-water system per unit mole in the U A and A—>B conformational transitions. The terms AF p, introduced to take into account the... 

An increased yield stress is required [62] in order to reverse the unfavourable conformations of the molecular chains that develop during annealing. This explanation is supported by the energy changes observed in annealed polymers. The enthalpy difference, as determined by DSC was AH = 1.8 J/g (Sect. 4.2), whereas the additional work required for yielding in an annealed sample was... 

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