UNSPECIFIED (1999) Native-state hydrogen-exchange studies of a fragment complex can provide structural information about the isolated fragments. In: Proceedings of the National Academy of Sciences of the United States of America, April-1999, Bangalore,India.
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Ordered protein complexes are often formed from partially ordered fragments that are difficult to structurally characterize by conventional NMR and crystallographic techniques. We show that concentration-dependent hydrogen exchange studies of a fragment complex can provide structural information about the solution structures of the isolated fragments. This general methodology can be applied to any bimolecular or multimeric system. The experimental system used here consists of Ribonuclease S, a complex of two fragments of Ribonuclease A. Ribonuclease S and Ribonuclease A have identical three-dimensional structures but exhibit significant differences in their dynamics and stability. We show that the apparent large dynamic differences between Ribonuclease A and Ribonuclease S are caused by small amounts of free fragments in equilibrium with the folded complex, and that amide exchange rates in Ribonuclease S can be used to determine corresponding rates in the isolated fragments. The studies suggest that folded RNase A and the RNase S complex exhibit very similar dynamic behavior. Thus cleavage of a protein chain at a single site need not be accompanied by a large increase in flexibility of the complex relative to that of the uncleaved protein.
|Item Type:||Conference Proceedings|
|Additional Information:||copyright of this conference paper belongs to National Academy of Sciences|
|Department/Centre:||Division of Biological Sciences > Molecular Biophysics Unit
Division of Physical & Mathematical Sciences > Physics
|Date Deposited:||17 Oct 2007|
|Last Modified:||19 Sep 2010 04:40|
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