[RASMB] looking for a nice validation system

[Allen Minton]

Greetings -

We are trying to validate a new system for rapid characterization of 
reversible macromolecular heteroassociations and are looking for a 
nice 1-1 associating pair of macromolecules that have similar MWs 
(within a factor of 2).   The association constant should be between 
10^4 and 10^8 M^-1 under specified conditions.  Oh, yes, the 
reactants should be commercially available and not too expensive, as 
we are going to need a few mg of each.

Anybody out there have suggestions?  References to prior studies of 
these associations would be greatly appreciated.

Allen Minton