protein heterodimer seperated during purification with superdex200

[cheetah.zao at gmail.com]

hi,everyone

I have been working on purifying a protein heterodimer using affinity
column(one of target protein has a GST tag) and superdex200.

the first part went well, I got two bands in SDS gel, however, I met
something weird when using superdex200 to purify the eluents of the
affinity column: there were two main peaks,with one of my target
protein seperately.

Is it quit unusual for superdex200 to drag protein complex apart,

has anyone met this too? 


Zhao