Calculations of protein volumes: sensitivity analysis and parameter database.
BACKGROUND
The precise sizes of protein atoms in terms of occupied packing volume are of great importance. We have previously presented standard volumes for protein residues based on calculations with Voronoi-like polyhedra. To understand the applicability and limitations of our set, we investigated, in detail, the sensitivity of the volume calculations to a number of factors: (i) the van der Waals radii set, (ii) the criteria for including buried atoms in the calculations or atom selection, (iii) the method of positioning the dividing plane in polyhedra construction, and (iv) the set of structures used in the averaging.


RESULTS
We find that different radii sets have only moderate affects to the distribution and mean of volumes. Atom selection and dividing plane methods cause larger changes in protein atoms volumes. More significantly, we show how the variation in volumes appears to be clearly related to the quality of the structures analyzed, with higher quality structures giving consistently smaller average volumes with less variance.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA. JerryTsai@TAMU.edu
Jerry
J
Tsai
Mark
M
Gerstein
D000465:Algorithms; D030562:Databases, Protein; D020407:Internet; D008958:Models, Molecular; D015394:Molecular Structure; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D013329:Structure-Activity Relationship
D011506:Proteins