Patent ID: 8071348
Filing Date: 2011-12-06
Classification: C12N,Y10S

Abstract:
1. An isolated or recombinant mutant of human protein tyrosine phosphatase 1B (PTP1B), wherein the mutant consists of the human PTP1B with a replacement of the invariant glutamine residue at position 262 of the human PTP1B with an alanine residue and a replacement of the invariant aspartate residue at position 181 of the human PTP1B with an alanine residue, wherein position 262 of the human PTP1B corresponds to amino acid residue number 14 of SEQ ID NO:3; wherein the replacement residues together cause (i) a reduction in catalytic rate (k cat ) of the enzyme for hydrolysis of the EGFR 988-998 peptide DADEpYLIPQQG compared to PTP1B without said replacements, mutant D181A, and mutant Q262A, and (ii) an increase in substrate-binding affinity (decrease in K d ) of the enzyme for substrate A c -Asp-Ala-Asp-Glu-F 2 Pmp-Leu-NH 2 compared to PTP1B without said replacements, mutant D181A, mutant C215S, and mutant D181A/C215E.