title: Geometrical analysis of Cys-Cys bridges in proteins and their prediction from incomplete structural information.
abstract: Analysis of C-alpha atom positions from cysteines involved in disulphide bridges in protein crystals shows that their geometric characteristics are unique with respect to other Cys-Cys, non-bridging pairs.  They may be used for predicting disulphide connections in incompletely determined protein structures, such as low resolution crystallography or theoretical folding experiments.  The basic unit for analysis and prediction is the 3 x 3 distance matrix for Cx positions of residues (i - 1), Cys(i), (i +1) with (j - 1), Cys(j), (j + 1).  In each of its columns, row and diagonal vector--outer distances are larger than the central distance.  This analysis is compared with some analytical models.
authors.affiliation: Department of Pharmaceutical Chemistry, Hebrew University of Jerusalem, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Goldblum
authors.forename: R
authors.initials: R
authors.lastname: Rein
mesh_terms: D000465:Algorithms; D003039:Cobra Neurotoxin Proteins / Q000737:chemistry; D003460:Crystallization; D003461:Crystallography; D003545:Cysteine / Q000032:analysis*; D004220:Disulfides / Q000737:chemistry*; D007328:Insulin / Q000737:chemistry; D008433:Mathematics; D008958:Models, Molecular; D015394:Molecular Structure; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D012984:Software
chemical_list: D003039:Cobra Neurotoxin Proteins; D004220:Disulfides; D007328:Insulin; D011506:Proteins; D003545:Cysteine