title: Polyethylene glycol-potassium phosphate aqueous two-phase systems. Insertion of short peptide units into a protein and its effects on partitioning.
abstract: Two different tetrapeptides, AlaTrpTrpPro and AlaIleIlePro, were inserted near the C-terminus of the protein ZZT0. The Trp-rich peptide unit strongly increased both the partitioning of ZZT0 into the polyethylene glycol (PEG)-rich phase in a PEG-potassium phosphate aqueous two-phase system and its retention on PEG and propyl hydrophobic interaction chromatographic columns with potassium phosphate as eluent. Both the partitioning and the retention increased with increasing number of Trp-rich peptide units inserted into ZZT0. Insertion of Ile-rich tetrapeptide units affected the partitioning and retention to a much lesser extent. Partition data also indicated a folding of inserted Trp tetrapeptides units, probably to minimize their water contact.
authors.affiliation: Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Hassinen
authors.forename: K
authors.initials: K
authors.lastname: Köhler
authors.forename: A
authors.initials: A
authors.lastname: Veide
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002845:Chromatography; D004355:Drug Stability; D007074:Immunoglobulin G / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D010710:Phosphates; D011092:Polyethylene Glycols; D017680:Potassium Compounds; D011487:Protein Conformation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry*; D013205:Staphylococcal Protein A / Q000737:chemistry; D013329:Structure-Activity Relationship; D014867:Water
chemical_list: D007074:Immunoglobulin G; D009842:Oligopeptides; D010710:Phosphates; D017680:Potassium Compounds; D011994:Recombinant Proteins; D013205:Staphylococcal Protein A; D014867:Water; D011092:Polyethylene Glycols; C013216:potassium phosphate