Specific anionic residues of the recombinant kringle 2 domain of tissue-type plasminogen activator that are responsible for stabilization of its interaction with .omega.-amino acid ligands

The involvement of specific aspartic acid (D) and glutamic acid (E) residues of the recombinant (r) kringle 2 (K2) domain of tissue-type plasminogen activator (tPA) in stabilizing its interaction with ω-amino acid ligands has been assessed by examination of these binding events subsequent to site-directed mutagenesis of the relevant amino acid residues. We have expressed and purified nonconservative alanine (A) replacement mutants at the following amino acid sequence locations in r-K2 tPA :E 17 (r-[K2 tPA /E 17 A]), E 75 (r-[K2 tPA /E 75 A]), and D 78 (r-[K2 tPA /D 78 A])