title: Suppressing mutation-induced protein aggregation in mammalian cells by mutating residues significantly displaced upon the original mutation.
abstract: Mutations introduced to wild-type proteins naturally, or intentionally via protein engineering, often lead to protein aggregation. In particular, protein aggregation within mammalian cells has significant implications in the disease pathology and biologics production; making protein aggregation modulation within mammalian cells a very important engineering topic. Previously, we showed that the semi-rational design approach can be used to reduce the intracellular aggregation of a protein by recovering the conformational stability that was lowered by the mutation. However, this approach has limited utility when no rational design approach to enhance conformational stability is readily available. In order to overcome this limitation, we investigated whether the modification of residues significantly displaced upon the original mutation is an effective way to reduce protein aggregation in mammalian cells. As a model system, human copper, zinc superoxide dismutase mutant containing glycine to alanine mutation at position 93 (SOD1G93A) was used. A panel of mutations was introduced into residues substantially displaced upon the G93A mutation. By using cell-based aggregation assays, we identified several novel variants of SOD1G93Awith reduced aggregation propensity within mammalian cells. Our findings successfully demonstrate that the aggregation of a mutant protein can be suppressed by mutating the residues significantly displaced upon the original mutation.
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904-4741, United States.
authors.forename: Simpson
authors.initials: S
authors.lastname: Gregoire
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904-4741, United States.
authors.forename: Kelly
authors.initials: K
authors.lastname: Glitzos
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904-4741, United States ; School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
authors.forename: Inchan
authors.initials: I
authors.lastname: Kwon
keywords: mammalian cells; mutation; protein aggregation; protein engineering; superoxide dismutase