GRable

GRable performs semi-automated Glyco-RIDGE analysis for site-specific glycoform analysis of intact glycoproteins with improved glycopeptide detection.

Key Features:

• Parallel clustering: This function improves the comprehensiveness of glycopeptide detection and allows the analysis to focus on specific glycan structures, such as pauci-mannose.
• Confidence evaluation: This function evaluates the confidence level of GRable results, especially using MS2 information, to reduce misassignment of core peptide and glycan composition.
• Correction function: This function enables accurate monoisotopic peak picking.
• One-to-one correspondence of clusters and core peptides: This enables accurate assignment even for multiply sialylated glycopeptides.
• Inter-cluster analysis: This function helps understand the reason for detected but unmatched clusters.

Scientific Applications:

• Site-specific glycoform analysis of intact glycoproteins: GRable enables large-scale and in-depth analysis of intact sialylated glycoproteins from purified and crude glycoprotein samples.
• Complementing MS2-based glycoproteomics: GRable improves comprehensiveness of glycopeptide detection to help analyze the status and changes in glycans for biological and clinical insights into protein glycosylation.

Methodology:

GRable implements the Glyco-RIDGE method, which detects glycopeptide signals as a cluster based on the mass and chromatographic properties of glycopeptides, then searches for each combination of core peptides and glycan compositions by matching their mass and retention time differences.