Hi, I do not use their method as such - however, I love heavy atom soaks and do them any time I can, so I've got very similar experiences in the past.
Heavy atoms can bind very quickly even from quite dilute solutions - the quickest I've ever soaked (and got useful data) was sodium chloroplatinate in under ten minutes at ~ 1mM concentration. The next quickest was K2Pt(NO2)4 which tends to take between 10 minutes and 30 minutes, almost regardless of the concentration. This is by far my favorite HAD reagent, incidentally. In general my soaks are all less than one hour with a few exceptions, such as iodine [not iodide!] soak to iodinate tyrosines which is typically better done during a day or so with very low amount of I2, via vapor phase. Artem > Hi, > > I'd like to find out how successful the "quick soak" method for heavy > atom derivatisation proposed by Radaev and Sun: > > Sun PD, Radaev S, Kattah M. Generating isomorphous heavy-atom > derivatives by a quick-soak method. Part I: test cases. Acta Cryst. > 2002. D58:1092-1098. > > has been in comparison to the "classical" method of longer soaks at > low concentrations of heavy atom compound. The method was quite > successful in our hands a few years ago but (fortunately?) it's > becoming increasingly rare that we use heavy atoms. I understand that > evidence will necessarily be anecdotal, but let's not let that stop us. > > Derek > -- > Derek Logan tel: +46 46 222 1443 > Associate professor fax: +46 46 222 4692 > Molecular Biophysics mob: +46 76 8585 707 > Lund University > Box 124, Lund, Sweden > > >
