Sandbox Reserved 197: Difference between revisions
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== '''Introduction''' == | == '''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. Bombardment causes the | 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. Bombardment causes the molecules to ionize so they can be detected by mass spectrometry. 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]. | ||
Observations of ribonuclease folding helped Christian Anfinsen win the Nobel Prize in 1972 for his work on protein folding [http://nobelprize.org/nobel_prizes/chemistry/laureates/1972/anfinsen-lecture.html]. Although RNase A has 105 possible disulfide bond pairings, only one occurs. This unique observation leads to the "thermodynamic hypothesis", that a protein's native state is determined by the thermodynamic favorability of he whole system, thus the tertiary structure must be predetermined by intramolecular interactions within the amino acid sequence. Since thermodynamic stability of a protein is effected by the temperature, pH, and ionic strength, among other factors, the protein structure can only exist under physiological conditions. Today, the correlation between the amino acid sequence and the tertiary structure of RNase A continues to serve as a model for protein folding. Among the most important attributes of this model are noncovalent interactions, proline orientations, and disulfide bonding. | Observations of ribonuclease folding helped Christian Anfinsen win the Nobel Prize in 1972 for his work on protein folding [http://nobelprize.org/nobel_prizes/chemistry/laureates/1972/anfinsen-lecture.html]. Although RNase A has 105 possible disulfide bond pairings, only one occurs. This unique observation leads to the "thermodynamic hypothesis", that a protein's native state is determined by the thermodynamic favorability of he whole system, thus the tertiary structure must be predetermined by intramolecular interactions within the amino acid sequence. Since thermodynamic stability of a protein is effected by the temperature, pH, and ionic strength, among other factors, the protein structure can only exist under physiological conditions. Today, the correlation between the amino acid sequence and the tertiary structure of RNase A continues to serve as a model for protein folding. Among the most important attributes of this model are noncovalent interactions, proline orientations, and disulfide bonding. | ||
