A core-satellite-structured composite material has been successfully synthesized for capturing glycosylated peptides or proteins. This novel hybrid material is composed of a silica-coated ferrite "core" and numerous "satellites" of gold nanoparticles with lots of "anchors". The anchor, 3-aminophenylboronic acid, designed for capturing target molecules, is highly specific toward glycosylated species. The long organic chains bridging the gold surface and the anchors could reduce the steric hindrance among the bound molecules and suppress nonspecific bindings. Due to the excellent structure of the current material, the trap-and-release enrichment of glycosylated samples is quite simple, specific, and effective. Indeed, the composite nanoparticles could be used for enriching glycosylated peptides and proteins with very low concentrations, and the enriched samples can be easily separated from bulk solution by a magnet. By using this strategy, the recovery of glycopeptides and glycoproteins after enrichment were found to be 85.9 and 71.6% separately, whereas the adsorption capacity of the composite nanoparticles was proven to be more than 79 mg of glycoproteins per gram of the material. Moreover, the new composite nanoparticles were applied to enrich glycosylated proteins from human colorectal cancer tissues for identification of N-glycosylation sites. In all, 194 unique glycosylation sites mapped to 155 different glycoproteins have been identified, of which 165 sites (85.1%) were newly identified.

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We invented a new method for highly efficient and specific enrichment of glycopeptides using two different nanomaterials synergistically. One is boronic-acid-functionalized Fe3O4 nanoparticles, enriching glycopeptides through formation of cyclic boronate esters between the boronic acid groups and the cis-diol groups on glycopeptides. The other nanomaterial is conventional poly(methyl methacrylate) nanobeads, which have strong adsorption toward nonglycopeptides. By optimizing the proportion of these two materials, extremely high sensitivity and selectivity are achieved in analyzing the standard glycopeptides/nonglycopeptides mixture solutions. Since the washing step is not necessary for these conditions, the enrichment process is simplified and the recovery efficiency of target glycopeptides reaches 90%. Finally, this approach is successfully applied to analyze human serum with the sample volume as little as 1 μL, in which 147 different N-glycosylation peptides within 66 unique glycoproteins are identified. All these performances by the synergistic enrichment are much better than employing one specific enrichment agent alone.

In plants, the circadian clock is an endogenous mechanism that controls a wide range of biological processes. To date, as one of the key world crops, little is known about the molecular mechanism and components of the circadian clock in maize (Zea mays). In this study, we characterized the CIRCADIAN CLOCK ASSOCIATED1 gene of maize (ZmCCA1), an ortholog of CCA1 in Arabidopsis thaliana (AtCCA1). Quantitative real-time PCR analysis revealed that ZmCCA1 was expressed in leaves and stem apex meristems in a rhythmic pattern under long day and short day conditions, and its peak gene expression appeared during the morning. ZmCCA1 transcripts accumulated in all tissues evaluated, with higher levels in tassels and ears. Additionally, the expression of another photoperiod gene ZmTOC1 peaked 12 h after dawn on long days and at 10 h after dawn on short days. Subcellular localization analysis revealed that the ZmCCA1 protein is directed to the cell nucleus. Overexpression of ZmCCA1 in Arabidopsis reduced the expression levels of downstream genes, including GIGANTEA (AtGI), CONSTANS (AtCO), and FLOWERING LOCUST (AtFT), and resulted in longer hypocotyls and delayed flowering. Taken together, our data suggest that ZmCCA1 may be a core component of the circadian clock in maize.

The launch of the Chromosome-Centric Human Proteome Project provides an opportunity to gain insight into the human proteome. The Chinese Human Chromosome Proteome Consortium has initiated proteomic exploration of protein-encoding genes on human chromosomes 1, 8, and 20. Collaboration within the consortium has generated a comprehensive proteome data set using normal and carcinomatous tissues from human liver, stomach, and colon and 13 cell lines originating in these organs. We identified 12,101 proteins (59.8% coverage against Swiss-Prot human entries) with a protein false discovery rate of less than 1%. On chromosome 1, 1,252 proteins mapping to 1,227 genes, representing 60.9% of Swiss-Prot entries, were identified; however, 805 proteins remain unidentified, suggesting that analysis of more diverse samples using more advanced proteomic technologies is required. Genes encoding the unidentified proteins were concentrated in seven blocks, located at p36, q12-21, and q42-44, partly consistent with correlation of these blocks with cancers of the liver, stomach, and colon. Combined transcriptome, proteome, and cofunctionality analyses confirmed 23 coexpression clusters containing 165 genes. Biological information, including chromosome structure, GC content, and protein coexpression pattern was analyzed using multilayered, circular visualization and tabular visualization. Details of data analysis and updates are available in the Chinese Chromosome-Centric Human Proteome Database ( http://proteomeview.hupo.org.cn/chromosome/ ).