title: Packing forces in ribonuclease crystals.
abstract: Packing in Ribonuclease A and Ribonuclease S crystals have been compared in order to determine the possible role of the precipitant on lattice contacts. Both proteins have similar tertiary structures, but they crystallize in different space groups depending on the precipitating agent. It is found that packing differs either by the number of nearest neighbours or by the size of surface areas buried in individual contacts. Ammonium sulfate seems to promote hydrophobic interactions with interfaces similar to those found in oligomeric proteins. Organic precipitants favour electrostatic interactions.
authors.affiliation: Laboratoire de Biologie physico-chimique, Université Paris Sud, Orsay, France.
authors.forename: M P
authors.initials: MP
authors.lastname: Crosio
authors.forename: F
authors.initials: F
authors.lastname: Rodier
authors.forename: M
authors.initials: M
authors.lastname: Jullien
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001412:Bacillus subtilis / Q000201:enzymology; D002417:Cattle; D006860:Hydrogen Bonding; D010179:Pancreas / Q000201:enzymology; D011487:Protein Conformation; D012259:Ribonuclease, Pancreatic / Q000737:chemistry*; D012260:Ribonucleases / Q000737:chemistry*; D012995:Solubility; D014961:X-Ray Diffraction
chemical_list: D000596:Amino Acids; D012260:Ribonucleases; D012259:Ribonuclease, Pancreatic; C022542:ribonuclease S