title: Quantitive evaluation of macromolecular crystallization experiments using 1,8-ANS fluorescence.
abstract: Modern X-ray structure analysis and advances in high-throughput robotics have allowed a significant increase in the number of conditions screened for a given sample volume. An efficient evaluation of the increased amount of crystallization trials in order to identify successful experiments is now urgently required. A novel approach is presented for the visualization of crystallization experiments using fluorescence from trace amounts of a nonspecific dye. The fluorescence images obtained strongly contrast protein crystals against other phenomena, such as precipitation and phase separation. Novel software has been developed to quantitatively evaluate the crystallization outcome based on a biophysical metric correlated with voxel protein concentration. In >1500 trials, 85.6% of the successful crystallization experiments were correctly identified, yielding a 50% reduction in the number of 'missed hits' compared with current automated approaches. The use of the method in the crystallization of three previously uncharacterized proteins from the malarial parasite Plasmodium falciparum is further demonstrated.
authors.affiliation: EMBL Hamburg, c/o DESY, Building 25a, Notkestrasse 85, Hamburg 22603, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Watts
authors.forename: Jochen
authors.initials: J
authors.lastname: Müller-Dieckmann
authors.forename: Gohar
authors.initials: G
authors.lastname: Tsakanova
authors.forename: Victor S
authors.initials: VS
authors.lastname: Lamzin
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Groves
mesh_terms: D000817:Anilino Naphthalenesulfonates / Q000032:analysis*; D000818:Animals; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods*; D019286:Endopeptidase K / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry; D010963:Plasmodium falciparum / Q000201:enzymology; D012984:Software
chemical_list: D000817:Anilino Naphthalenesulfonates; C027132:1-anilino-8-naphthalenesulfonate; D009113:Muramidase; D019286:Endopeptidase K