Sugahara Michihiro, Kunishima Naoki
Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, Sayo-gun, Hyogo 679-5148, Japan.
Acta Crystallogr D Biol Crystallogr. 2006 May;62(Pt 5):520-6. doi: 10.1107/S0907444906009012. Epub 2006 Apr 19.
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.
确定合适的冷冻保护剂条件是蛋白质X射线晶体学中耗时的过程之一。通过使用五种不同蛋白质的晶体进行低温衍射实验，评估了两种新型通用冷冻保护剂（油基和水基类型）的适应性。结果表明，油基和水基冷冻保护剂的互补使用能够成功地对蛋白质晶体进行冷冻保护。由于通用冷冻保护剂不含结晶溶液，在存在重原子试剂的情况下，使用这些冷冻保护剂可以快速有效地制备重原子衍生物。研究了四种重原子试剂[K(2)PtCl(4)、HgCl(2)、KAu(CN)(2)和K(2)Pt(CN)(4)]，它们在通用冷冻保护剂中可储存一个多月，仍具有足够的衍生化能力。
