ISSN:
0887-3585
Keywords:
ribonuclease A
;
protein deamidation
;
protein conformation
;
disulfide bonds
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
The effect of the folded conformation of a protein on the rate of deamidation of a specific asparaginyl residue has been determine. Native and unfolded ribonuclease A (RNase A) could be compared under identical conditions, because stable unfolded protein was generated by breaking irreversibly the protein disulfide bonds.Deamidation of the labile Asn-67 residue of RNase A was followedelectrophoretically and chromatographically. At 80°C, similar rates of deamidation were observed for the disulfidebonded form, which is thermally unfolded, and the reduced form. At 37°C and pH 8, however, the rate of deamidation of native RNase A was negligible, and was more than 30-fold slower than that of reduced, unfolded RNase A. This demonstrates that the Asn-67 residue is located in a local conformation in the native protein that greatly inhibits deamidation. This conformation is the β-turn of residues 66-68.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prot.340050103
Permalink
