Puzzled

[Dr Engelbert Buxbaum]

Am 11.10.2007, 07:51 Uhr, schrieb Yvonne Couch  
<yvonne.couch from dpag.ox.ac.uk>:

> if I am stimulating
> my cells with an unknown substance and I want to know what cell surface
> receptor it is binding to how do I go about this without systematically
> knocking down every known receptor or running a microarray.  Is it  
> possible?

You will need a labelled version of your substance, usually radioactive  
isotopes are used. With those you can find those fractions of solubilised  
cell membranes which have significant binding. A more direct approach is  
the use of photoaffinity labels (e.g. azido-groups) where you incubate the  
cells, flash them with UV-light and then isolate labelled bands from  
SDS-PAGE gels. Note that some natural substances (e.g. ATP) are  
photoaffinity labels in their own right. See for example

@book{Scr-84,
         Editor= {E.F. Scriven},
         TITLE= {Azides and nitrenes},
         YEAR= {1987},
         PUBLISHER= {Academic Press},
         LANGUAGE= {engl}
}