Region shrink-wrap

Once the pharmacophore is generated, the active compounds are superimposed and the shrink-wrap surface, defined as the surface of smallest volume that encloses at least one conformer of each active molecule, is calculated. This surface can be analyzed to provide raw shape information (figure 10). Regions of the shrink-wrap surface that are penetrated by inactives that otherwise match the pharmacophore can be marked as forbidden regions . Other regions which haven t been explored can be marked as terra incognita , or unknown regions. 

The shrink-wrap method derives its name from the manner in which AR construction is carried out, and the geometric resemblance of this process to that of wrapping shrink-wrap over an object. Candidate ARs are constructed by the successive removal of unattainable points from the stoichiometric subspace. This is in contrast to the IDEAS approach, which grows regions outward. 

A candidate AR, represented by the shaded region, is given at iteration k of a typical construction process in the shrink-wrap method. The convex polytope, P , represents an approximation to the AR at iteration k in the construction, and is the set of extreme points contained within P. The... 

Manousiouthakis, V.I., Justanieah, A.M., Taylor, L.A., 2004. The shrink-wrap algorithm for the construction of the attainable region An application of the IDEAS framework. Comput. Chem. Eng. 28, 1563-1575. 

Posada, A., Manousiouthakis, V., 2008. Multi-feed attainable region construction using the shrink-wrap algorithm. Chem. Eng. Sci. 63, 5571-5592. 

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