Download MendeleyFatal amyloid formation in a patient's antibody light chain is caused by a single point mutation.
Kazman, P., Vielberg, M.T., Pulido Cendales, M.D., Hunziger, L., Weber, B., Hegenbart, U., Zacharias, M., Kohler, R., Schonland, S., Groll, M., Buchner, J.(2020) Elife 9
- PubMed: 32151314
- DOI: https://doi.org/10.7554/eLife.52300
- Primary Citation of Related Structures:
6SM1, 6SM2 - PubMed Abstract:
In systemic light chain amyloidosis, an overexpressed antibody light chain (LC) forms fibrils which deposit in organs and cause their failure. While it is well-established that mutations in the LC's V L domain are important prerequisites, the mechanisms which render a patient LC amyloidogenic are ill-defined. In this study, we performed an in-depth analysis of the factors and mutations responsible for the pathogenic transformation of a patient-derived λ LC, by recombinantly expressing variants in E. coli . We show that proteolytic cleavage of the patient LC resulting in an isolated V L domain is essential for fibril formation. Out of 11 mutations in the patient V L , only one, a leucine to valine mutation, is responsible for fibril formation. It disrupts a hydrophobic network rendering the C-terminal segment of V L more dynamic and decreasing domain stability. Thus, the combination of proteolytic cleavage and the destabilizing mutation trigger conformational changes that turn the LC pathogenic.
Organizational Affiliation:
Center for Integrated Protein Science Munich at the Department Chemie, Technische Universität München, Garching, Germany.
