title: Site-specific attachment of polyethylene glycol-like oligomers to proteins and peptides.
abstract: Modification of proteins with polymers is a viable method to tune protein properties, e.g., to render them more water-soluble by using hydrophilic polymers. We have utilized precision-length, polyethylene glycol-based oligomers carrying a thioester moiety in transthioesterification and native chemical ligation reactions with internal and N-terminal cysteine residues in proteins and peptides. These reactions lead to uniquely modified proteins with an increased solubility in chaotrope- and detergent-free aqueous systems. Polymer modification of internal cysteines is fully reversible and allows generation of stable protein-polymer conjugates for enzymatic manipulations as demonstrated by proteolytic cleavage of a protein construct that was only soluble in buffers incompatible with protease activity before polymer modification. The permanent polymer modification of a Rab protein at its N-terminal cysteine produced a fully active Rab variant that was efficiently prenylated. Thus, PEGylation of prenylated proteins might be a viable route to increase water solubility of such proteins in order to carry out experiments in detergent- and lipid-free systems.
authors.affiliation: Max-Planck Institute of Molecular Physiology, Department of Physical Biochemistry, Otto-Hahn Str. 11, 44227 Dortmund, Germany.
authors.forename: Yoann
authors.initials: Y
authors.lastname: Marsac
authors.forename: Janina
authors.initials: J
authors.lastname: Cramer
authors.forename: Diana
authors.initials: D
authors.lastname: Olschewski
authors.forename: Kirill
authors.initials: K
authors.lastname: Alexandrov
authors.forename: Christian F W
authors.initials: CF
authors.lastname: Becker
mesh_terms: D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011328:Prions / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D020691:rab GTP-Binding Proteins / Q000737:chemistry*
chemical_list: D010455:Peptides; D011328:Prions; D011092:Polyethylene Glycols; D020691:rab GTP-Binding Proteins