title: Determination of molecular envelopes from solvent contrast variation data.
abstract: An algorithm is described for determining macromolecular envelopes from crystal diffraction amplitudes measured from a solvent contrast variation series. The method uses solvent contrast variation data that have been preprocessed to represent the structure-factor amplitudes of the envelope. The amplitudes are phased using an iterative projection algorithm that incorporates connectivity and compactness constraints on the envelope. The algorithm is tested by simulation on two protein envelopes and shown to be effective even in the absence of the very low resolution data, which are difficult to access experimentally.
authors.affiliation: Computational Imaging Group, Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand.
authors.forename: Victor
authors.initials: V
authors.lastname: Lo
authors.forename: Richard L
authors.initials: RL
authors.lastname: Kingston
authors.forename: R P
authors.initials: RP
authors.lastname: Millane
mesh_terms: D000465:Algorithms; D001426:Bacterial Proteins / Q000737:chemistry; D018360:Crystallography, X-Ray / Q000379:methods*; D010450:Endopeptidases / Q000737:chemistry; D037161:Galectins / Q000737:chemistry; D006801:Humans; D008962:Models, Theoretical; D011506:Proteins / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000737:chemistry; D012997:Solvents
chemical_list: D001426:Bacterial Proteins; D037161:Galectins; C092525:LGALS7 protein, human; D011506:Proteins; D012997:Solvents; D010450:Endopeptidases; C087822:alkaline protease