Molecular Design of Glycoprotein Mimetics: Glycoblotting by Engineered Proteins with an Oxylamino‐Functionalized Amino Acid Residue

Abstract

The general and efficient method for the site-directed glycosylation of proteins is a key step in order to understand the biological importance of the carbohydrate chains of proteins and to control functional roles of the engineered glycoproteins in terms of the development of improved glycoprotein therapeutics. We have developed a novel method for site-directed glycosylation of proteins based on chemoselective blotting of common reducing sugars by genetically encoded proteins. The oxylamino-functionalized L-homoserine residues, 2-amino-4-O-(N-methylaminooxy) butanoic acid and 2-amino-4-aminooxy butanoic acid, were efficiently incorporated into proteins by using the four-base codon/anticodon pair strategy in Escherichia coli in vitro translation. Direct and chemoselective coupling between unmodified simple sugars and N-methylaminooxy group displayed on the engineered streptavidin allowed for the combinatorial synthesis of novel glycoprotein mimetics.

Lectin-Binding Specificity of the Fertilization-Relevant Protein PDC-109 by Means of Surface Plasmon Resonance and Carbohydrate REcognition Domain EXcision-Mass Spectrometry

“…Although several glycoconjugates have been synthesized by other laboratories using also N [Me]-Aoa-peptide versions as mimics of natural glycoproteins, few of them have been used as probes for interaction studies [ 35 , 36 ], and not always with conclusive results. Thus, this work represents a further step to establish our SPR-approach as a reliable alternative in carbohydrate-lectin interaction studies.…”

Pyranose N-Glycosyl Amines: Emerging Targets With Diverse Biological Potential

“…Glycoprotein mimics such as 45 (Fig. 19) are accessible in a combinatorial fashion using a simple hydroxylamine linker between the saccharide moiety and the polypeptide [81], while a hydrazide linker serves to conjugate carrier proteins to sugars, for example the LewisY tetrasaccharide in 46 [82]. The quaternary ammonium-linked glucuronide of trans-4-hydroxytamoxifen (47), constructed by displacement on a glucuronosyl bromide by a protected tamoxifen precursor, has been prepared to study the metabolism of tamoxifen itself [83].…”

Recent Developments in Neoglycopeptide Synthesis

“…Nishimura et al [71] introduced amino-oxy-and methylamino-oxy-substituted homoalanines into streptavidin, and were able to couple several unmodified glycosides in a combinatorial fashion.…”