On Nov 16, 2012, at 12:26 PM, Ronald E Stenkamp wrote: > I'm a little confused. Petsko and others were doing > low-temperature/freezing/vitrification crystal experiments in the 1970s, > right? (J. Mol. Biol., 96(3) 381, 1975). Is there a big difference between > what they were doing and what's done now. > > Ron
>From Greg's paper: "Since the mixed solvents used are fluid at low temperatures, diffusion of substrate into the crystals should be possible if the viscosity is not too high." One of his goals in the work reported in this paper was find fluid media that could be used at very low temperatures that would allow him to diffuse in substrates and trap a Michaelis complex and solve its structure. This is a bit different than the current "typical" cryopreservation practices that result in a solid system at or below 100K. It is noted that some increase in crystal lifetime is observed at the cold but not cryogenic temperatures explored in his work. Everyone will surely agree that he is one of the pioneers in collecting data on macromolecular crystals at low temperature.
