Site-selective modification of proteins for the synthesis of structurally defined multivalent scaffolds

Abstract

A combination of classical site-directed mutagenesis, genetic code engineering and bioorthogonal reactions delivered a chemically modified barstar protein with one or four carbohydrates installed at specific residues. These protein conjugates were employed in multivalent binding studies, which support the use of proteins as structurally defined scaffolds for the presentation of multivalent ligands.Post-translational protein modifications play an important role in the regulation and organization of biological processes of living organisms and are therefore of common scientific interest.

A Protein‐Based Pentavalent Inhibitor of the Cholera Toxin B‐Subunit

“…As the majority of the structure comes as a ready-made building block, the synthetic route to the inhibitor is relatively short. Previous attempts to introduce sugars at defined sites on an ankyrin repeat protein [10] and the barstar protein [11] led to ligands and inhibitors of plant lectins. However, as no attempts were made to match the size and spacing of the ligands to the binding sites, these multivalent compounds led to only modest enhancements in activity and/or lectin aggregation, which may be undesirable.…”

Templated chemistry for bioorganic synthesis and chemical biology

“…A unimolecular template connects the functional units within a single molecular entity that may serve as a stand-alone scaffold or may be conjugated with another molecular unit. Typical examples ( Figure 1B) for stand-alone templates are small molecule scaffolds such as cyclodextrins (1), 20 calixarenes (2), 21 and many more as well as larger molecules such as dendrimers (3), [22][23][24] peptides (including oligoproline 4), [25][26][27][28][29] or even entire proteins (8) 30 or polymers (5). 31,32 In another application scenario, conjugated unimolecular templates are frequently used as reaction scaffolds to facilitate chemical reactions such as ligation auxiliaries in protein synthesis via native chemical ligation (NCL) (vide infra).…”

Multivalenz als chemisches Organisations‐ und Wirkprinzip

“…[121] Durch etablierte Konjugationsmethoden konnten so maßgeschneiderte, multivalente Biomoleküle für eine effiziente Lectininhibition generiert werden (Abbildung 12).…”

“…[119] Die Glycosylliganden wurden In jüngster Zeit ist es auch gelungen, durch ortsspezifische Mutagenese und Gencode-Engineering mehrere bioortho-gonale Funktionalisierungen zielgerichtet an ganzen Proteinen einzuführen. [121] Durch etablierte Konjugationsmethoden konnten so maßgeschneiderte, multivalente Biomoleküle für eine effiziente Lectininhibition generiert werden (Abbildung 12).…”