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An easy method for retrieving atomic coordinates from CPK space‐filling molecular models
Author(s) -
De Haën Christoph,
Swanson Eric,
Teller David C.
Publication year - 1976
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1976.360150915
Subject(s) - space (punctuation) , chemistry , energy minimization , orthogonal coordinates , crystallography , diffraction , geometry , algorithm , physics , computer science , computational chemistry , optics , mathematics , operating system
Connectors for CPK space‐filling molecular models have been supplemented with pointed steel wires (ϕ = 1.59 mm) of appropriate lengths and positions to represent atomic bonds. For illustration purposes, the polypeptide backbone of glucagon was equipped with such wire‐core connectors and given a possible conformation. The molecular model was packed into a cubic box and, using a clinical instrument, X‐ray films were taken from three orthogonal directions. Atomic coordinates on the films were then corrected to real‐space coordinates. This method for retrieving atomic coordinates from space‐filling models of modium‐sized polypeptides is easy and can be done wih equipement available everywhere. Coordinates obtained in this way should be useful as starting points for energy minimization, for the calculation of frictional coefficients, and in attempts to solve crystal structures by X‐ray diffraction, using molecular replacement methodology.