Bioinspired Saccharide–Saccharide Interaction and Smart Polymer for Specific Enrichment of Sialylated Glycopeptides

Abstract

Abnormal sialylation of proteins is highly associated with many major diseases, such as cancers and neurodegenerative diseases. However, this study is challenging owing to the difficulty in enriching trace sialylated glycopeptides (SGs) from highly complex biosamples. The key to solving this problem relies strongly on the design of novel SG receptors to capture the sialic acid (SA) moieties in a specific and tunable manner. Inspired by the saccharide-saccharide interactions in life systems, here we introduce saccharide-based SG receptors into this study. Allose (a monosaccharide) displays specific and pH-sensitive binding toward SAs. Integrating allose units into a polyacrylamide chain generates a saccharide-responsive smart copolymer (SRSC). Such design significantly improves the selectivity of SA binding; meanwhile, this binding can be intelligently triggered in a large extent by solution polarity and pH. As a result, SRSC exhibits high-performance enrichment capacity toward SGs, even under 500-fold interference of bovine serum albumins digests, which is notably higher than conventional materials. In real biosamples of HeLa cell lysates, 180 sialylated glycosylation sites (SGSs) have been identified using SRSC. This is apparently superior to those obtained by SA-binding lectins including WGA (18 SGSs) and SNA (22 SGSs). Furthermore, lactose displays good chemoselectivity toward diverse disaccharides, which indicated the good potential of lactose-based material in glycan discrimination. Subsequently, the lactose-based SRSC facilitates the stepwise isolation of O-linked or N-linked SGs with the same peptide sequence but varied glycans by CH3CN/H2O gradients. This study opens a new avenue for next generation of glycopeptide enrichment materials.

Mass spectrometry for protein sialoglycosylation

“…Sialylated glycopeptides are specifically captured by the magnetic nanoparticles via the weak anion exchange and hydrophilic interaction . Recently, two novel materials, kapok fiber and sugar‐integrated smart copolymer, are found to have high specificity toward sialylated glycopeptides through hydrogen bonding interactions . In particular, kapok fiber is a readily available natural biomaterial and can selectively enrich sialoglycopeptides without loss of sialic acid, showing good potential for analytical applications.…”

“…118 Recently, two novel materials, kapok fiber and sugar-integrated smart copolymer, are found to have high specificity toward sialylated glycopeptides through hydrogen bonding interactions. 119,120 In particular, kapok fiber is a readily available natural biomaterial and can selectively enrich sialoglycopeptides without loss of sialic acid, showing good potential for analytical applications. However, although these techniques have shown some advantages in isolating sialylated glycopeptides from complex biological mixtures, simple and high throughput protocols for routine enrichment are still currently lacking.…”

New Opportunities and Challenges of Smart Polymers in Post‐Translational Modification Proteomics

“…Our group also developed a three‐component saccharide‐responsive polymer film, which displayed distinct adsorption behavior, surface wettability, and adhesion force changes toward different disaccharides; in addition, its GP enrichment performance was satisfactory. In our recent work,[77a] CCI was introduced as a new binding force for designing a carbohydrate receptor. Through monosaccharide screening, allose was found to have specific and pH‐sensitive binding toward Neu5Ac, a typical sialic acid.…”

“…Hydrogen bonds are indicated by the blue dashed lines. [77a] e) Hydropathy‐based searching strategy for screening out the optimal dipeptide sequences for saccharide recognition and discrimination. The dipeptide‐based homopolymer [e.g., poly(Pro‐Glu)] displays accurate discrimination of glycosidic linkage isomers of oligosaccharides; as shown in typical extracted ion chromatograms (f), each GP splits into two or more peaks (corresponding to different glycosidic linkage isomers) on a poly(Pro‐Glu)‐based chromatographic column.…”

Cobalt Phthalocyanine Tetracarboxylic Acid Functionalized Polymer Monolith for Selective Enrichment of Glycopeptides and Glycans

“…A variety of studies has revealed that glycoproteins can be used as biomarkers for many diseases . MS is a powerful tool for analyzing protein glycosylation, however, the direct determination of glycoproteins with MS still presents great challenge due to their low abundance in biosamples and poor ionization efficiency in MS analysis . For this goal, various purification and enrichment processes are employed prior to MS analysis.…”