α2-Macroglobulins: structure and function
| Autor: | F. Xavier Gomis-Rüth, Irene Garcia-Ferrer, Aniebrys Marrero, Theodoros Goulas |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
chemistry.chemical_classification Conformational changes Conformational change 030102 biochemistry & molecular biology medicine.diagnostic_test biology Chemistry Proteolysis Antimicrobial peptides Virulence biology.organism_classification Growth factor and cytokine regulator Endopeptidase Cell biology Cell wall 03 medical and health sciences 030104 developmental biology Enzyme medicine Venus flytrap Proteinase inhibitor Macroglobulin |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Subcellular Biochemistry ISBN: 9783319465012 |
| Popis: | Harris J., Marles-Wright J. (eds) α2-macroglobulins are broad-spectrum endopeptidase inhibitors, which have to date been characterised from metazoans (vertebrates and invertebrates) and Gram-negative bacteria. Their structural and biochemical properties reveal two related modes of action: the “Venus flytrap” and the “snap-trap” mechanisms. In both cases, peptidases trigger a massive conformational rearrangement of α2-macroglobulin after cutting in a highly flexible bait region, which results in their entrapment. In some homologs, a second action takes place that involves a highly reactive β-cysteinyl-γ-glutamyl thioester bond, which covalently binds cleaving peptidases and thus contributes to the further stabilization of the enzyme:inhibitor complex. Trapped peptidases are still active, but have restricted access to their substrates due to steric hindrance. In this way, the human α2-macroglobulin homolog regulates proteolysis in complex biological processes, such as nutrition, signalling, and tissue remodelling, but also defends the host organism against attacks by external toxins and other virulence factors during infection and envenomation. In parallel, it participates in several other biological functions by modifying the activity of cytokines and regulating hormones, growth factors, lipid factors and other proteins, which has a great impact on physiology. Likewise, bacterial α2-macroglobulins may participate in defence by protecting cell wall components from attacking peptidases, or in host-pathogen interactions through recognition of host peptidases and/or antimicrobial peptides. α2-macroglobulins are more widespread than initially thought and exert multifunctional roles in both eukaryotes and prokaryotes, therefore, their on-going study is essential. |
| Databáze: | OpenAIRE |
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