Glycan Reader

Glycan Reader annotates glycans in Protein Data Bank (PDB) and PDBx/mmCIF structural files by detecting sugar residues, glycosidic linkages, and chemical modifications to support structural analysis and molecular simulation.

Key Features:

• Automatic Detection and Annotation: Identifies sugars and glycosidic linkages within PDB/PDBx/mmCIF files using atomic coordinates and connectivity information.
• Comprehensive Chemical Modification Recognition: Recognizes a wide array of sugar types and chemical modifications, including glycolipids and carbohydrate derivatives present in PDB entries.
• Format Support: Parses both PDB and PDBx/mmCIF file formats for structural glycan data.
• Editable Glycan Structures: Allows addition, deletion, or modification of glycosylation types, sugar types, chemical modifications, glycosidic linkages, and anomeric states in glycan models.
• Simulation System Integration: Generates simulation systems and input files compatible with CHARMM, NAMD, GROMACS, AMBER, GENESIS, LAMMPS, Desmond, OpenMM, and CHARMM/OpenMM.
• Glycan Fragment Database: Provides glycan sequence search capability via the updated Glycan Structure.Org database for complex glycan structures with chemical modifications observed in the PDB.

Scientific Applications:

• Protein–Glycan Interaction Analysis: Enables detailed annotation of glycans for studies of protein–glycan interfaces and structural interpretation.
• Glycobiology Research: Supports investigations into glycans' roles in cell signaling, immune response, and pathogen–host interactions by identifying modified sugar species and linkages.
• Molecular Dynamics and Drug Discovery: Produces simulation-ready systems and inputs to facilitate molecular dynamics studies and modeling efforts targeting glycoconjugates.

Methodology:

Detection and annotation use atomic coordinates and connectivity information; the software parses PDB and PDBx/mmCIF files, recognizes sugar types and chemical modifications (including glycolipids), generates simulation systems and input files for listed MD engines, and provides glycan sequence search via the Glycan Structure.Org database.