In vitro deamidation of human triosephosphate isomerase

Arch Biochem Biophys. 1986 Aug 1;248(2):452-9. doi: 10.1016/0003-9861(86)90498-4.


The effects of pH, temperature, buffer ion, ionic strength, protein concentration, and substrate on the rates of specific, spontaneous deamidations of Asn-15 and Asn-71 of human triosephosphate isomerase were examined. Elevated temperature and pH facilitate the deamidations, and the deamidation rate is dependent on the specific buffer ions indicating a general base catalysis mechanism. The presence of substrate also enhances the rates of deamidation. The effect of substrate may be related to conformational changes in the catalytic center which are known to cause changes in the subunit-subunit contact sites where Asn-15 and Asn-71 are located. The enhanced deamidation in the presence of substrate may, in part, account for the more rapid rate of deamidation observed in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Asparagine / metabolism*
  • Buffers
  • Carbohydrate Epimerases / metabolism*
  • Dihydroxyacetone Phosphate / metabolism
  • Glutamine / metabolism*
  • Glyceraldehyde 3-Phosphate / metabolism
  • Humans
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Ions
  • Isoenzymes / metabolism
  • Osmolar Concentration
  • Temperature
  • Triose-Phosphate Isomerase / metabolism*


  • Buffers
  • Ions
  • Isoenzymes
  • Glutamine
  • Glyceraldehyde 3-Phosphate
  • Dihydroxyacetone Phosphate
  • Asparagine
  • Carbohydrate Epimerases
  • Triose-Phosphate Isomerase