DelPhi (software)

For the Integrated Development Environment (IDE), see Embarcadero Delphi.
DelPhi

The electrostatic field lines of TRAP---trp RNA binding attenuation protein (PDB ID: 2EXS). The blue and red colors represent the positive and negative polarities, respectively. The field lines indicate the directions of the electrostatic forces surrounding the protein.
Original author(s) Barry Honig
Developer(s) DelPhi Development Team
Operating system Linux, Mac OS X, Microsoft Windows
Website http://compbio.clemson.edu/delphi

DelPhi is a scientific application which calculates electrostatic potentials in and around macromolecules and the corresponding electrostatic energies. It incorporates the effects of ionic strength mediated screening by evaluating the Poisson-Boltzmann equation at a finite number of points within a three-dimensional grid box.

One of the main problems in modeling the electrostatic potential of biological macromolecules is that they exist in water at a given ionic strength and that they have an irregular shape. Analytical solutions of the corresponding Poisson-Boltzmann Equation (PBE) are not available for such cases and the distribution of the potential can be found only numerically. DelPhi, developed in Professor Barry Honig's lab in 1986, was the first PBE solver used by many researchers. The widespread popularity of DelPhi is due to its speed, accuracy (calculation of the electrostatic free energy is only slightly dependent on the resolution of the grid) and the ability to handle extremely high grid dimensions.

Additional features such as assigning different dielectric constants to different regions of space, smooth Gaussian-based dielectric distribution function,[1] modeling the electrostatic potential distribution across biological membranes,[2] modeling geometric objects and charge distributions, and treating systems containing mixed salt solutions also attracted many researchers. In addition to the typical potential map, DelPhi can generate and output the calculated distribution of either the dielectric constant or ion concentration, providing the biomedical community with extra tools for their research.[3] [4] [5]

Delphi distribution comes as a sequential as well as parallelized codes, runs on Linux, Mac OS X and Microsoft Windows systems and the source code is available in Fortran 95 and C++ programming languages. DELPHI is also implemented into an accessible web-server.[6] DELPHI has also been utilized to build a server that predicts pKa's of biological macromolecules such as proteins, RNAs and DNAs which can be accessed via web.[7]

Pdb files are typically used as input for DelPhi calculations. Other required inputs are an atomic radii file and a charge file .[8] Binary Potential files as output from DelPhi can be viewed in most molecular viewers such as UCSF Chimera, Jmol, and VMD, and can either be mapped onto surfaces or visualized at a fixed cutoff.[9]

DelPhi is commonly used in protein science to visualize variations in electrostatics along a protein or other macromolecular surface and to calculate the electrostatic components of various energies.[10]

See also

External links

References

  1. ↑ Li L, Li C, Zhang Z, Alexov E. (April 2013). "On the Dielectric "Constant" of Proteins: Smooth Dielectric Function for Macromolecular Modeling and Its Implementation in DelPhi". J Chem Theory Comput 9 (4): 2126–2136.
  2. ↑ Dias RP, Li L, Soares TA, Alexov E. (July 2015). "Modeling the electrostatic potential of asymmetric lipopolysaccharide membranes: the MEMPOT algorithm implemented in DelPhi". J Comput Chem 35 (19): 1418–29. doi:10.1002/jcc.23632. PMID 24799021.
  3. ↑ "Software:DelPhi". Honig Lab. Columbia University.
  4. ↑ Rocchia W, Sridharan S, Nicholls A, Alexov E, Chiabrera A, Honig B (January 2002). "Rapid grid-based construction of the molecular surface and the use of induced surface charge to calculate reaction field energies: applications to the molecular systems and geometric objects". J Comput Chem 23 (1): 128–37. doi:10.1002/jcc.1161. PMID 11913378.
  5. ↑ Li L, Li C, Sarkar S, Zhang J, Witham S, Zhang Z, Wang L, Smith N, Petukh M, Alexov E. (May 2012). "DelPhi: a comprehensive suite for DelPhi software and associated resources.". BMC Biophysics 5: 9. doi:10.1186/2046-1682-5-9. PMID 22583952.
  6. ↑ "DelPhi Webserver".
  7. ↑ "DelPhiPka Webserver".
  8. ↑ "DelPhi Parameter Files".
  9. ↑ DelPhi manual
  10. ↑ Rohs R, West SM, Sosinsky A, Liu P, Mann RS, Honig B (October 2009). "The role of DNA shape in protein-DNA recognition". Nature 461 (7268): 1248–53. doi:10.1038/nature08473. PMC 2793086. PMID 19865164.


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