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A new program for optimizing periodic boundary models of solvated biomolecules (PBCAID)

✍ Scribed by Xiaoliang Qian; Daniel Strahs; Tamar Schlick


Publisher
John Wiley and Sons
Year
2001
Tongue
English
Weight
309 KB
Volume
22
Category
Article
ISSN
0192-8651

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✦ Synopsis


Abstract

Simulations of solvated macromolecules often use periodic lattices to account for long‐range electrostatics and to approximate the surface effects of bulk solvent. The large percentage of solvent molecules in such models (compared to macromolecular atoms) makes these procedures computationally expensive. The cost can be reduced by using periodic cells containing an optimized number of solvent molecules (subject to a minimal distance between the solute and the periodic images). We introduce an easy‐to‐use program “PBCAID” to initialize and optimize a periodic lattice specified as one of several known space‐filling polyhedra. PBCAID reduces the volume of the periodic cell by finding the solute rotation that yields the smallest periodic cell dimensions. The algorithm examines rotations by using only a subset of surface atoms to measure solute/image distances, and by optimizing the distance between the solute and the periodic cell surface. Once the cell dimension is optimized, PBCAID incorporates a procedure for solvating the domain with water by filling the cell with a water lattice derived from an ice structure scaled to the bulk density of water. Results show that PBCAID can optimize system volumes by 20 to 70% and lead to computational savings in the nonbonded computations from reduced solvent sizes. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1843–1850, 2001