From: Borries Demeler <demeler@bioc09.v19.uthscsa.edu>
  To  : Jim Bloom <Jim.Bloom.B@bayer.com>
  Date: Thu, 27 Apr 2000 12:44:54 -0500 (CDT)

Re: variation of local lnks

> 
> I have been following this discussion with much interest and not having any
> compunctions about making a fool of myself I will so do.....I have been in the
> biochemistry business for going on 30 years now and I hate to admit it but I
> have never heard of either competent or incompetent monomers or dimers.   What
> does competent and incompetent mean (other than referring to my scientific
> abilities) in plain english that even I can understand??
>  Jim
> 

Jim, in the context of this thread, consider my situation:

My sample is a heme-containing protein, and it appears that the 
heme group is necessary to cause dimerization (as well as higher order
species). There is a population in the protein prep that somehow
lost its heme group, establishing a mixture of chemically similar,
but not identical proteins. While the MW is still approximately the
same, the properties are different, in particular the association
property. So when I talk about incompetent monomer, I mean this
subpopulation of monomers that are unable to associate.

Sometimes you have the opposite effect - once a protein is dimerized,
it becomes irreversibly linked, maybe through photo crosslinks or 
cystein oxidation disulfide bridges. THis is an irreversible (or
incompetent) dimer.

Hope that clarifies it...
-Borries