X-PLOR is a software package for computational structural biology originally developed by Axel Brunger

Axel T. Brunger

Axel T. Brunger is a German American biophysicist and Professor of Molecular and Cellular Physiology, and Neurology and Neurological Sciences at Stanford University, and an Howard Hughes Medical Institute Investigator.- Early life :...

 at Yale University

Yale University

Yale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...

. It was first published in 1987 as an off-shoot of CHARMM

CHARMM

CHARMM is the name of a widely used set of force fields for molecular dynamics as well as the name for the molecular dynamics simulation and analysis package associated with them...

 - a similar program that ran on Cray supercomputers. It is used in the fields of X-ray crystallography

X-ray crystallography

X-ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and causes the beam of light to spread into many specific directions. From the angles and intensities of these diffracted beams, a crystallographer can produce a...

 and NMR

Protein nuclear magnetic resonance spectroscopy

Nuclear magnetic resonance spectroscopy of proteins is a field of structural biology in which NMR spectroscopy is used to obtain information about the structure and dynamics of proteins. The field was pioneered by Richard R. Ernst and Kurt Wüthrich, among others...

analysis.

X-PLOR is a highly sophisticated computer program that provides an interface between theoretical foundations and experimental data in structural biology, with specific emphasis on X-ray crystallography and nuclear magnetic resonance spectroscopy in solution of biological macro-molecules. It is intended primarily for researchers and students in the fields of computational chemistry, structural biology, and computational molecular biology.