Sandbox Reserved 197: Difference between revisions

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[[Image:proteopedia 2d2.png|thumb|450px|Structure of RNase A. Disulfide bonds between cysteine residues are shown in red and proline residues are shown in green. Pink regions indicate β-sheets, blue regions indicate α-helixes and tan regions indicate loop structures.]]

== '''Introduction''' ==

Ribonuclease A is an enzyme found in the pancreas that is involved in catalyzing RNA degradation [http://www.uta.edu/faculty/sawasthi/Enzymology-4351-5324/Class%20Syllabus%20Enzymology/ribonucleaseA.pdf].  The kidney-shaped structure of RNase A has been determined through crystallography [http://en.wikipedia.org/wiki/Crystallography] and Fast Atom Bombardment Mass Spectrometry [http://en.wikipedia.org/wiki/Fast_atom_bombardment].  FABMS is performed by mixing the material to be analyzed (RNase A) with a non-volatile environment called a matrix and is then bombarded by high energy molecules within a vacuum.  Through this technique it has been found that RNase A is composed of four anti-parallel β-sheets and three α-helixes. Presence of four disulfide bonds and two ''cis'' proline residues greatly effect the structure and folding kinetics of RNase A [http://nobelprize.org/nobel_prizes/chemistry/laureates/1972/anfinsen-bio.html].  Perhaps most widely known as the protein that helped Christian Anfinsen win the Nobel Prize for his work on protein folding, RNase A has been shown to spontaneously fold back into its native conformation following degradation to its primary structure.  The Anfinsen experiment has ignited the interest in protein folding. Today, the correlation between the amino acid sequence and the tertiary structure of RNase A continues to serve as a model for protein folding.