TY - JOUR
T1 - Distinguishing the specificities of closely related proteases
T2 - role of p3 in substrate and inhibitor discrimination between tissue type plasminogen activator and urokinase
AU - Ke, Song Hua
AU - Coombs, Gary S.
AU - Tachias, Kathy
AU - Navre, Marc
AU - Corey, David R.
AU - Madison, Edwin L.
PY - 1997
Y1 - 1997
N2 - Elucidating subtle specificity differences between closely related enzymes is a fundamental challenge for both enzymology and drug design. We have addressed this issue for two intimately related serine proteases, tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (uPA), by modifying the technique of substrate phage display to create substrate subtraction libraries. Characterization of individual members of the substrate subtraction library accomplished the rapid, direct identification of smalt, highly selective substrates for t-PA. Comparison of the amino acid sequences of these selective substrates with the consensus sequence for optimal substrates for t-PA, derived using standard substrate phage display protocols, suggested that the P3 and P4 residues are the primary determinants of the ability of a substrate to discriminate between t-PA and u-PA. Mutagenesis of the P3 and P4 residues of plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of both t-PA and u-PA, confirmed this prediction and indicated a predominant role for the P3 residue. Appropriate replacement of both the P3 and P4 residues enhanced the t-PA specificity of PAI-1 by a factor of 600, and mutation of the P3 residue alone increased this selectivity by a factor of 170. These results demonstrate that the combination of substrate phage display and substrate subtraction methods can be used to discover specificity differences between very closely related enzymes and that this information can be utilized to create highly selective inhibitors.
AB - Elucidating subtle specificity differences between closely related enzymes is a fundamental challenge for both enzymology and drug design. We have addressed this issue for two intimately related serine proteases, tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (uPA), by modifying the technique of substrate phage display to create substrate subtraction libraries. Characterization of individual members of the substrate subtraction library accomplished the rapid, direct identification of smalt, highly selective substrates for t-PA. Comparison of the amino acid sequences of these selective substrates with the consensus sequence for optimal substrates for t-PA, derived using standard substrate phage display protocols, suggested that the P3 and P4 residues are the primary determinants of the ability of a substrate to discriminate between t-PA and u-PA. Mutagenesis of the P3 and P4 residues of plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of both t-PA and u-PA, confirmed this prediction and indicated a predominant role for the P3 residue. Appropriate replacement of both the P3 and P4 residues enhanced the t-PA specificity of PAI-1 by a factor of 600, and mutation of the P3 residue alone increased this selectivity by a factor of 170. These results demonstrate that the combination of substrate phage display and substrate subtraction methods can be used to discover specificity differences between very closely related enzymes and that this information can be utilized to create highly selective inhibitors.
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M3 - Article
AN - SCOPUS:33846655757
SN - 1369-0191
VL - 11
SP - 51
JO - Fibrinolysis and Proteolysis
JF - Fibrinolysis and Proteolysis
IS - SUPPL. 3
ER -