Mutations affecting the activity of urokinase-type plasminogen activator |
| |
Authors: | Davidow Lance S; Dumais Dennis R; Smyth Adienne P; Greer Jonathan; Moir Donald T |
| |
Affiliation: | Collaborative Research Inc 1365 Main St. Waltham, MA 02154
2Computer Assisted Molecular Design Group D-47E, Abbott Laboratories, Abbott Park, IL 60064-3500, USA |
| |
Abstract: | Mutagenesis throughout the single-chain urokinase-type plasminogenactivator (scu-PA) cDNA molecule, followed by expression ofthe mutant genes and secretion of the resulting mutant proteinsfrom yeast, has been used to determine the amino acid residuesimportant for activity of scu-PA molecules. Twelve out of 13colonies secreting variant scu-PA molecules with decreased abilityto form a zone of fibrinolysis had mutant genes with a singlecodon alteration in the serine protease encoding domain (B-chain).Many of these changes are of highly conserved residues in theserine proteases and are consequently of considerable interest.A model three-dimensional structure of the protease domain ofurokinase was used to explain the basis for the effects of thesedown mutations. The model showed that the strongest down mutationsresult from either interference of the mutated side chain withsubstrate binding at the active site or the introduction ofbulky or charged groups at structurally sensitive internal positionsin the molecule. Attempts to find second site revertants offive down mutants, altered either at the plasmin activationsite or near the serine at the active site, only resulted insame-site revertants, with the original or closely related aminoacids restored. |
| |
Keywords: | plasminogen activators/ prourokinase/ scu-PA/ serine proteases/ urokinase |
本文献已被 Oxford 等数据库收录! |
|