Table of Contents
Critical Points and Local FeaturesGenerating the Critical PointsThe critical points are generated by finding the minima, maxima, and saddle points of the distance function to backbone alpha carbon atoms. This is effectively same as finding the Delaunay Tesselation (The code for finding Delaunay Tesselation of a given set of 3D coordinates is given in software package directory LFMPro/CriticalPoints/Delaunay/delaunay.cpp). The critical points are represented as the center of the tetrahedra in the Voronoi diagram and the neighborhood of the critical point is defined as a sphere that passes through the corners of the tetrahedra. A filtering step removes the critical points with small persistence values or small neighborhoods (The code for calculating persistence values is given in software directory LFMPro/CriticalPoints/alphashape.py). The critical points that are formed by the artifacts in the pdb structure (e.g., breaks/gaps in the structure) are also removed. The number of critical points generated from a protein is roughly of 10 times as the number of amino-acids. The actual number depends on the conformation of the amino acids in 3D space. The filtering step we applied reduce this number to be in the same range as the number of amino acids. Generating Local FeaturesFor each of the critical points, we endow geometrical and chemical features. The following table summarizes the local features we have used to summarize a given neighborhood:
Extending LFMPro
If you wish to incorporate new features into LFMPro, please edit
If you want to redefine the way local centers and their neighborhoods are defined, |