title: Heat, pH induced aggregation and surface hydrophobicity of S. cerevesiae Ssa1 protein.
abstract: Heat shock protein 70 is a conserved protein among organisms. Hsp70 helps substrate proteins to fold correctly. Unfolded substrate proteins increase the probability of the aggregate formation. High level recombinant protein expression in biotechnology often leads insoluble inclusion bodies. To prevent aggregation and to obtain high levels of soluble proteins, Hsp co-expression with desired recombinant protein in yeast becomes a popular method. For this purpose, S. cerevesiae cytosolic Hsp70 (Ssa1) biochemical properties were characterized. Alteration of Ssa1 structure between ATP- and ADP-bound states regulates its function. Therefore, conformation-dependent Ssa1 hydrophobicity and as a result aggregation may also play a key role in Ssa1 function. Therefore, a combination of FTIR, acrylamide quenching, and ANS was used to investigate the effect of nucleotide binding on the structure of Ssa1. Ssa1 secondary structure alterations and hydrophobic properties in aqueous solutions with differing ionic strengths and temperature were also studied.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Cumhuriyet University, 58140, Sivas, Turkey. ytutar@cumhuriyet.edu.tr
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Tutar
authors.forename: Derya
authors.initials: D
authors.lastname: Arslan
authors.forename: Lütfi
authors.initials: L
authors.lastname: Tutar
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D012995:Solubility
chemical_list: D018840:HSP70 Heat-Shock Proteins; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C095973:SSA1 protein, S cerevisiae