br Methods and materials br Results and discussion

Methods and materials
Results and discussion
Conclusions This is the first study that attempted to isolate, purify and identify the characteristics of MK2 Inhibitor IV sale from ginseng. In vitro studies have demonstrated that PGL-1 efficiently suppressed SH-SY5Y cell apoptosis induced by Aβ25–35, possibly through the inhibition of Aβ-induced NO overproduction. Additionally, PGL-1 significantly improved the learning and memory ability of AD rats. These findings suggest that glycoproteins derived from ginseng might be a promising anti-AD reagent. Future studies would be continued to explore the underlying mechanism of ginseng-mediated neuroprotection.
Introduction Glycosylation is one of the most common and vital post-translational modification of proteins and has essential roles in a variety of biological processes, such as cell–cell communication, molecular recognition, protein folding, and immune responses (Li et al., 2015). Glycoproteins that contain glycan covalently attached to a polypeptide backbone play a vital role in biological processes (Xie, Zhong, Cai, Chen, & Chen, 2017). A number of studies have suggested that more than half of all proteins are glycosylated (Gorg, Weiss, & Dunn, 2004). Therefore, research on the bioactivities and structures of glycoproteins has attracted attention (Dai et al., 2016). However, because non-glycoproteins are more abundant than glycoproteins, the latter are prone to be disturbed and covered by non-glycoproteins. Thus, it is important to enrich the less common glycoproteins. Recently, hydrazide chemistry, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and chromatography have been commonly used for enriching glycoproteins. Hydrazide chemistry was used to enrich the N-linked glycoproteins; however, in this study, a series of side reactions occurred during the reaction process (Jiang, Messing, & Ye, 2017). SDS-PAGE is used for identifying the purity of proteins, and for separating target proteins from complex samples. However, the low sensitivity of the method is limited to obtaining high-purity glycoproteins. Lectin affinity chromatography as a general method can reversibly and selectively enrich specific types of glycosylated peptides or proteins (Rowe, El Khoury, & Lowe, 2016). Lectins are carbohydrate-binding proteins (or glycoproteins) of non-immune origin that agglutinate cells and/or precipitate glycoconjugates; all plant lectins possess at least one non-catalytic domain, which binds reversibly to a specific mono- or oligosaccharide (Van Damme, Peumans, Barre, & Rouge, 1998). Different structures of glycopeptides can be enriched by different lectins. ConA specifically binds mannosyl and glucosyl residues of polysaccharides and glycoproteins containing free hydroxyl groups at positions C3, C4, and C6, and can serve as a tool to capture N-glycosylated peptides and proteins with broad specificity (Idil et al., 2015). Wheat germ agglutinin (WGA) binds both N-acetylglucosamine and Nacetylneuraminic acid. The significant advantage of lectin-based technology is that, following minimal sample preparation, a simultaneous quantitative analysis of N- and O-linked glycans on intact biological structures can be performed without the need for glycan release (Fry et al., 2011). Boronate affinity chromatography is the preferred method for binding with cis-diol-containing glycoproteins and saccharides, and this method has been used in various studies (Rowe et al., 2016, Yang et al., 2011). Boronate affinity materials, including magnetic materials, have aroused enormous interest for the enrichment of glycoproteins (Jiang et al., 2017). Magnetic particles are preferred carriers for enriching glycoproteins (Idil et al., 2015). The use of magnetic particles in supporting the functionalization has several advantages, such as durable magnetic susceptibility, and can be combined with the advantages of a lectin-based approach, which is flexible, convenient, and reversible. In addition, it is convenient to identify the structure and bioactives of a single glycan.