Engineering of conformations of plasminogen activator inhibitor-1. A crucial role of beta-strand 5A residues in the transition of active form to latent and substrate forms
| العنوان: | Engineering of conformations of plasminogen activator inhibitor-1. A crucial role of beta-strand 5A residues in the transition of active form to latent and substrate forms |
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| المؤلفون: | Rikke Egelund, Kees W. Rodenburg, Peter A. Andreasen, Signe Jensen, Tove Kirkegaard, Susanne L. Schousboe, Helle H. Petersen |
| المصدر: | European Journal of Biochemistry. 263:577-586 |
| بيانات النشر: | Wiley, 1999. |
| سنة النشر: | 1999 |
| مصطلحات موضوعية: | Models, Molecular, Time Factors, Protein Conformation, Stereochemistry, Mutant, Temperature, Beta sheet, Substrate (chemistry), Serpin, Protein Engineering, Biochemistry, Recombinant Proteins, Serine, chemistry.chemical_compound, Protein structure, chemistry, Plasminogen activator inhibitor-1, Plasminogen Activator Inhibitor 1, Mutagenesis, Site-Directed, Humans, Amino Acids, Plasminogen activator |
| الوصف: | The serpin (serine proteinase inhibitor) family is of general protein chemical interest because of its ability to undergo large conformational changes, in which the surface-exposed reactive centre loop (RCL) is inserted as strand 4 in the large central beta-sheet A. Loop insertion is an integral part of the inhibitory mechanism and also takes place at conversion of serpins to the latent state, occurring spontaneously only in plasminogen activator inhibitor-1 (PAI-1). We have investigated the importance of beta-strand 5A residues for the activity and latency transition of PAI-1. An approximately fourfold increase in the rate of latency transition resulted from His-substitution of Gln324 (position 334 in the alpha(1)-proteinase inhibitor template numbering), which interacts with the underlying alpha-helix B. The side chains of Gln321 and Lys325 (template residues 331 and 335, respectively) form hydrogen bonds to the peptide backbone of a loop connecting alpha-helix F and beta-strand 3A. While substitution with Ala of Glu321 had only minor effects on the properties of PAI-1, substitution with Ala of Lys325 led to stabilization of the inhibitory activity at incubation conditions leading to conversion of wild-type PAI-1 to a substrate form, and to an anomalous reaction towards a monoclonal antibody, which induced a delay in the latency transition of the mutant, but not wild-type PAI-1. We conclude that the anchoring of beta-strand 5A plays a crucial role in loop insertion. These findings provide new information about the mechanism of an important example of protein conformational changes. |
| تدمد: | 1432-1033 0014-2956 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a4833a0439f23d16d94232b11c40cbab https://doi.org/10.1046/j.1432-1327.1999.00545.x |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....a4833a0439f23d16d94232b11c40cbab |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14321033 00142956 |
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