title: Novel versatile cryoprotectants for heavy-atom derivatization of protein crystals.
abstract: Determination of a suitable cryoprotectant agent condition is one of the time-consuming processes in protein X-ray crystallography. The adaptability of two novel versatile cryoprotectants (oil- and water-based types) has been evaluated by cryodiffraction experiments using crystals of five different proteins. The results suggest that complementary use of both oil- and water-based cryoprotectants enables the successful cryoprotection of protein crystals. Since the versatile cryoprotectants do not contain crystallization solution, rapid and efficient preparation of heavy-atom derivatives is possible with these cryoprotectants in the presence of heavy-atom reagents. Four heavy-atom reagents [K(2)PtCl(4), HgCl(2), KAu(CN)(2) and K(2)Pt(CN)(4)] were examined and could be stored with sufficient derivatizing capabilities for over one month in the versatile cryoprotectants.
authors.affiliation: Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Sugahara
authors.forename: Naoki
authors.initials: N
authors.lastname: Kunishima
mesh_terms: D003451:Cryoprotective Agents / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods*; D007202:Indicators and Reagents; D019216:Metals, Heavy / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*
chemical_list: D003451:Cryoprotective Agents; D007202:Indicators and Reagents; D019216:Metals, Heavy; D011506:Proteins