Roles of aspartic acid-181 and serine-222 in intermediate formation and hydrolysis of the mammalian protein-tyrosine-phosphatase PTP1.

@article{Lohse1997RolesOA,
  title={Roles of aspartic acid-181 and serine-222 in intermediate formation and hydrolysis of the mammalian protein-tyrosine-phosphatase PTP1.},
  author={Daniel L. Lohse and John M Denu and Nicholas Santoro and Jack E. Dixon},
  journal={Biochemistry},
  year={1997},
  volume={36 15},
  pages={4568-75}
}
Protein tyrosine phosphatases (PTPases) share a number of conserved amino acid residues, including the active site sequence HCXXGXXRS(T), which are strongly implicated in catalysis. The roles of two conserved active site residues, Asp-181 and Ser-222, were investigated using a combination of site-directed mutagenesis and kinetic analysis in the mammalian PTPase PTP1. The pH profiles for k(cat)/K(m) and k(cat) of the wild-type enzyme indicate that two ionizable groups, of pK(a) values 5.1 and 5… CONTINUE READING