Region definition

Pastor M, G Cruciani and S dementi 1997. Smart Region Definition A New Way to Improve tl Predictive Ability and Interpretability of Three-Dimensional Quantitative Structure-Activi Relationships. Journal of Medicinal Chemistry 40 1455-1464. 

Pastor, M., Cruciani, G., and Clementi, S. Smart region definition a new way to improve the predictive ability and interpretability of three-dimensional quantitative structure-activity relationships./. Med. Chem. 1997, 40, 1455-1464. 

When output is finished the program is ready for a new region definition. A negative start position will stop the program. 

The structure based virtual screening process includes also the use of some keywords. With these keywords FLAP fdters out matches and keeps them only if they make sense in terms of binding site shape. FLAP can also allow additional binding site volume (cavity expansion, useful when the protein structure under investigation is an homology model) and with the use of regions (definition of a sphere within each pharmacophore needs to have at least one point) or selection of a probe (enforcing a particular feature to be present in the calculated pharmacophores) certain constraints can also be added. 

Graph Theoretic Approach. The multiscale segmentation behavior just described may efficiently be posed as a graph problem. As such, we will in this section review some basic graph theory and region definitions. 

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