The M32L substitution mutation of staphylococcal nuclease was made to test the theoretical prediction by Yamaotsu, Moriguchi and Hirono that it would be approximately 1.6 kcal/mol more stable than the wild-type protein. Instead M32L and the closely related M32I mutant were 0.8 and 0.6 kcal/mol less stable than the wild-type protein, respectively. The theoretical treatment had successfully predicted the stability effects of other mutations in staphylococcal nuclease. The discrepancy found here may be due to a general problem of the theoretical treatment, such as inadequate molecular dynamics simulation time, or possibly due to more specific difficulty in assessing the strength of the sulfur-aromatic interaction that is present in the wild-type. Study holds ProTherm entries: 7781, 7782, 7783, 7784, 7785, 7786 Extra Details: protein folding; denaturation;,sulfur-aromatic interactions; mutation
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:34 p.m.
|Number of data points||20|
|Proteins||Thermonuclease ; Thermonuclease|
|Assays/Quantities/Protocols||Experimental Assay: Cm ; Experimental Assay: Tm ; Experimental Assay: dHvH ; Experimental Assay: Cm temp:20.0 C ; Experimental Assay: m ; Experimental Assay: dG_H2O ; Derived Quantity: dTm ; Derived Quantity: ddG_H2O|
|Libraries||Mutations for sequence ATSTKKLHKEPATLIKAIDGDTVKLMYKGQPMTFRLLLVDTPETKHPKKGVEKYGPEASAFTKKMVENAKKIEVEFDKGQRTDKYGRGLAYIYADGKMVNEALVRQGLAKVAYVYKPNNTHEQHLRKSEAQAKKEKLNIWSEDNADSGQ|