title: Degradation of structurally characterized proteins injected into HeLa cells. Tests of hypotheses.
abstract: We have compared sequence and structural features of 35 proteins to their metabolic stabilities in HeLa cells. No relationship was observed between the half-life of an injected protein and its subunit molecular weight, isoelectric point, hydrophobicity, thermostability, surface charge density, or N-terminal residue. Other properties, including susceptibility to oxidation, specific combinations of amino acids, secondary structure composition, and solvent exposed residues, also failed to correlate with protein stability. Although a weak inverse correlation was obtained when stability was compared to asparagine and glutamine content, we conclude that the degradation of an injected protein is unlikely to be related to any single structural parameter. Rather, we hypothesize that it results from an interplay between subcellular location and still poorly defined surface features of the injected proteins.
authors.affiliation: Department of Biology, University of Utah, Salt Lake City 84132.
authors.forename: S W
authors.initials: SW
authors.lastname: Rogers
authors.forename: M
authors.initials: M
authors.lastname: Rechsteiner
mesh_terms: D000595:Amino Acid Sequence; D004355:Drug Stability; D006207:Half-Life; D006367:HeLa Cells / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008962:Models, Theoretical; D011487:Protein Conformation; D011506:Proteins / Q000378:metabolism*; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D046911:Macromolecular Substances; D011506:Proteins