SPECTROSCOPY, IMAGING, OTHER TECHNIQUES |
New applications of composition gradient static light scattering: (1) Characterization of concurrent reversible protein self- and hetero-association equilibria in solution. (2) Characterization of concentration-dependent size distributions of a protein undergoing reversible linear indefinite self-association
Keiichi Kameyama 1 and Allen P. Minton 1*
1 National Institutes of Health
* To whom correspondence should be addressed. E-mail: minton{at}helix.nih.gov.
Submitted on September 12, 2005
Revised on October 10, 2005
Accepted on 22 November 2005
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Abstract |
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The recently developed technique of composition gradient static light scattering (CG-SLS) is demonstrated to be capable of detecting and quantitatively characterizing reversible association of chymotrypsin and bovine pancreatic trypsin inhibitor in a solution mixture and simultaneously occurring reversible self-association of chymotrypsin at low pH in the same mixture. Results of moderate precision may be obtained from a single experiment of the type described by Attri & Minton (Analytical Biochem, 346:132-138, 2005), requiring less than 15 minutes and less 1 than mg of each protein. The precision with which hetero-association equilibrium constants may be determined can be improved if the value of equilibrium constants for self-association are determined independently as described by Attri & Minton (Analytical Biochem. 337:103-110, 2005). The results of CG-SLS experiments carried out on FtsZ, a protein that undergoes reversible linear indefinite self-association in the presence of guanosine diphosphate, may be utilized to characterize the composition-dependent distribution of oligomer size under a particular set of buffer conditions.
Key Words:
FtsZ, Rayleigh light scattering, bovine pancreatic trypsin inhibitor, chymotrypsin, protein-protein association
