title: Mutagenesis modulates the uptake efficiency, cell-selectivity, and functional enzyme delivery of a protein transduction domain.
abstract: Alanine scanning mutagenesis of a recently reported prostate cancer cell-selective Protein Transduction Domain (PTD) was used to assess the specific contribution each residue plays in cell uptake efficiency and cell-selectivity. These studies resulted in the identification of two key residues. Extensive mutagenesis at these key residues generated multiple mutants with significantly improved uptake efficiency and cell-selectivity profiles for targeted cells. The best mutant exhibits ~19-fold better uptake efficiency and ~4-fold improved cell-selectivity for a human prostate cancer cell line. In addition, while the native PTD sequence was capable of delivering functional fluorescent protein to the interior of a prostate cancer cells, only modest functional enzyme delivery was achieved. In contrast, the most potent mutant was able to deliver large quantities of a functional enzyme to the interior of human prostate cancer cells. Taken together, the research described herein has significantly improved the efficiency, cell-selectivity, and functional utility of a prostate cancer PTD.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA. brian.mcnaughton@colostate.edu.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: DePorter
authors.forename: Irene
authors.initials: I
authors.lastname: Lui
authors.forename: Virginia J
authors.initials: VJ
authors.lastname: Bruce
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Gray
authors.forename: Monica
authors.initials: M
authors.lastname: Lopez-Islas
authors.forename: Brian R
authors.initials: BR
authors.lastname: McNaughton
mesh_terms: D000409:Alanine / Q000235:genetics*; D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D006801:Humans; D008297:Male; D016296:Mutagenesis; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D017434:Protein Structure, Tertiary / Q000235:genetics*; D014161:Transduction, Genetic
chemical_list: D000409:Alanine