[RASMB] pressure induced dissociation

[Arthur Rowe]

Hi Allen (& all)

Yes indeed - there was this story that a (reversible) myosin dimer  
existed. Trouble is, it was never found by electron microscopy, and  
detailed hydrodynamic analysis (Emes & Rowe, 1978 & Sara  
Suchet-Derechin - lost reference) equally failed to find anything other  
than monomer, over the (rather low) relevant range in c. Plus, the  
whole concept sat uneasily with the (later identified) 3-fold  
rotational symmetry of the native myosin filament. Nice to revisit the  
historic stuff!

But of course this is not to deny the simple fact that hydrostatic  
pressures of the order of 100+ bar are able to cause dissociation of  
oligomeric structures. People such as Mike Geeves of U of Canterbury -  
good to meet Mike a couple of weeks back at a Muscle Club Reunion Day -  
have long explored this effect in some detail. Google brings down  
loads. Synthetic myosin filaments  show this effect in the AUC (another  
Emes & Rowe paper, 1978).

Even some monomeric proteins have been shown to change s values*  
slightly (Errington et al 2001).

ABW to everyone

Arthur

*fully corrected for all other effects, including solvent density &  
viscosity changes with pressure

Emes C H & Rowe A J (1978) BBA 537 125-144
Emes C H & Rowe A J (1978) BBA 537 110-124
N Errington, P Mistry & A J Rowe (2001) “Protein hydration varies with  
protein crowding and with applied pressure: a sedimentation velocity  
study” Progr. Coll Polym Sci 119 58-63


On Jul 28, 2010, at 21:46, Allen Minton wrote:

>  For those of you interested in ancient history, have a look at this:
>
>
> An unusual pressure dependence for a reversibly associating protein  
> system; sedimentation studies on myosin.
>
>  Josephs R, Harrington WF.
>
>  Proc Natl Acad Sci U S A. 1967 Oct;58(4):1587-94.
>
>
>  What goes around, comes around.
>
>
>> At 10:58 AM 7/28/2010, smcbryan wrote:
>>
>>> All,
>>>  Would anyone/everyone care to comment on these results:
>>> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC389292/pdf/pnas00083 
>>> -0121.pdf
>>>  and perhaps generalize on how/if they present a common or uncommon
>>>  phenomenon in centrifugation.
>>>  Is this something that we should look out for, or is it very  
>>> specific to
>>>  this particular complex?
>>>  thanks,
>>>  steve
>>>
>>>  --
>>>  Steven McBryant, PhD
>>>  Director
>>>  Protein Production and Characterization Facility
>>>  Research Scientist/Scholar
>>>  Colorado State University
>>>  970-491-5586
>>>  _______________________________________________
>>>  RASMB mailing list
>>>  RASMB at rasmb.bbri.org
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************************************************************************ 
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Arthur J Rowe
Professor of Biomolecular Technology / Director NCMH Business Centre
School of Biosciences
University of Nottingham
Sutton Bonington
Leics LE12 5RD

TEL:  0115 9516156
FAX:  0115 0516157
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