caa a22 4500 445313048 CHVBK 20180317142636.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s11095-011-0468-8 doi (NATIONALLICENCE)springer-10.1007/s11095-011-0468-8 Multivalent and Flexible PEG-Nitrilotriacetic Acid Derivatives for Non-covalent Protein Pegylation [Elektronische Daten] [Anna Mero, Tetsuya Ishino, Irwin Chaiken, Francesco Veronese, Gianfranco Pasut] ABSTRACT: Purpose: A new approach for non-covalent protein PEGylation is translated from immobilized metal ion affinity chromatography, and based on metal coordination bonds between a chelating agent linked to PEG, nitrilotriacetic acid (NTA), and the ring nitrogen of histidines in a protein. Methods: PEG-NTA conjugates were synthesized differing in the number of NTA units and in the polymer structure. Three derivatives were investigated in association experiments with five model proteins. The most promising complex, PEG8-(NTA)8-Cu2+-G-CSF (granulocyte colony stimulating factor), was thoroughly characterized and the pharmacokinetic profile was evaluated in rats. Results: The experiments demonstrated that only PEG8-(NTA)8, bearing eight NTA molecules on flexible PEG arms, associated strongly with those proteins having several histidines. The protein secondary structure was not affected in the complex. PEG8-(NTA)8-Cu2+-G-CSF showed a K D of 4.7nM, as determined by surface plasmon resonance, but the association was not stable in vivo. Conclusions: PEG8-(NTA)8 is the first derivative able to associate with native proteins and form soluble complexes with a nanomolar K D. The study highlights the need of a multivalent and flexible coordination and encourages further investigations to increase the stability of PEG8-(NTA)8 complexes in vivo either through the use of protein mutants or His-tag proteins. Springer Science+Business Media, LLC, 2011 bioconjugation nationallicence drug delivery nationallicence PEGylation nationallicence protein delivery nationallicence Mero Anna Department of Pharmaceutical Sciences, University of Padua, via F. Marzolo 5, 35131, Padua, Italy aut Ishino Tetsuya Drexel University College of Medicine, Philadelphia, Pennsylvania, USA aut Chaiken Irwin Drexel University College of Medicine, Philadelphia, Pennsylvania, USA aut Veronese Francesco Department of Pharmaceutical Sciences, University of Padua, via F. Marzolo 5, 35131, Padua, Italy aut Pasut Gianfranco Department of Pharmaceutical Sciences, University of Padua, via F. Marzolo 5, 35131, Padua, Italy aut Pharmaceutical Research Springer US; http://www.springer-ny.com 28/10(2011-10-01), 2412-2421 0724-8741 28:10<2412 2011 28 11095 https://doi.org/10.1007/s11095-011-0468-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11095-011-0468-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mero Anna Department of Pharmaceutical Sciences, University of Padua, via F. Marzolo 5, 35131, Padua, Italy aut NATIONALLICENCE 700 1- Ishino Tetsuya Drexel University College of Medicine, Philadelphia, Pennsylvania, USA aut NATIONALLICENCE 700 1- Chaiken Irwin Drexel University College of Medicine, Philadelphia, Pennsylvania, USA aut NATIONALLICENCE 700 1- Veronese Francesco Department of Pharmaceutical Sciences, University of Padua, via F. Marzolo 5, 35131, Padua, Italy aut NATIONALLICENCE 700 1- Pasut Gianfranco Department of Pharmaceutical Sciences, University of Padua, via F. Marzolo 5, 35131, Padua, Italy aut NATIONALLICENCE 773 0- Pharmaceutical Research Springer US; http://www.springer-ny.com 28/10(2011-10-01), 2412-2421 0724-8741 28:10<2412 2011 28 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer