ColBuilder

Generate atomistic and coarse-grained models of collagen microfibrils with customizable crosslinking

📋 Table of Contents

• 📋 Table of Contents
• 📚 About
  • Key Features
• 🚀 Installation
  • Prerequisites
  • Step-by-Step Installation
  • Dependencies
    • PyMOL
    • muscle (Multiple Sequence Alignment)
    • UCSF Chimera
    • Modeller
• 🚀 Quick Start
• ⚙️ Operation Modes & Workflow
  • 🧠 Understanding PDB Types
  • 📊 Mode Summary Table
  • 🔁 Valid Mode Combinations
  • ✅ Valid Workflows
  • 🔧 Mode 4 (Mixing Crosslinks): Run Separately via Script
• 🔗 Collagen Crosslinks
  • Enzymatic Crosslinks
  • Non-Enzymatic Crosslinks (AGEs)
  • Crosslink Combinations
• 📖 Usage Guide
  • Basic Usage
  • Configuration Options
  • Example Workflows
    • Creating a Basic Human Collagen Microfibril
    • Generating a Crosslinked Bovine Microfibril
    • Creating a Mixed Crosslinked (80% Divalent + 20% Trivalent) Human Collagen Microfibril from Collagen Molecules
    • Generating a Coarse-Grained Topology File for MD Simulation
    • Generating Topology Files from an Existing Fibril (Topology-Only Mode)
    • Creating a Fibril with PYD Crosslinks
    • Replacing Crosslinks in an Existing Fibril
    • Adding AGE Crosslinks to an Existing Structure (Mutated PDB Workflow)
• 📚 Documentation
• 🤝 Contributing
• 📚 Publications & Citation
• 🙏 Acknowledgements

📚 About

ColBuilder is a specialized tool for generating atomistic and coarse-grained models of collagen microfibrils from single collagen molecules. Developed by the Gräter group at the Max Planck Institute for Polymer Research, it provides researchers with a flexible framework to create biologically relevant collagen structures for molecular dynamics simulations and structural studies.

Key Features

• Custom microfibril generation: Create collagen microfibrils from individual molecules or amino acid sequences with precise control over structural parameters
• Comprehensive crosslinking support: Model enzymatic (divalent and trivalent) and non-enzymatic (e.g., AGE) crosslinks with flexible positioning
• Highly configurable: Adjust collagen sequence, fibril geometry, crosslink types and density to match your custom conditions
• Multiple force fields: Generate topology files for both atomistic (Amber99) and coarse-grained (Martini3) simulations
• Flexible workflows: Run complete pipeline or individual steps
• Crosslink manipulation: Mix different crosslink types or reduce crosslink density in existing fibrils
• Simulation-ready output: Generate complete topology files compatible with GROMACS and other major MD packages
• Reproducible research: Standardized approach to collagen modeling ensures consistency across studies

🚀 Installation

Prerequisites

• Python 3.9 or later
• Git
• Conda package manager (we recommend miniforge)

Step-by-Step Installation

1. Create and activate a conda environment:

   conda create -n colbuilder python=3.9
   conda activate colbuilder

2. Clone the repository:

   git clone git@github.com:graeter-group/colbuilder.git
   cd colbuilder

3. Install ColBuilder:

   pip install .

Dependencies

ColBuilder requires several external tools to function properly:

PyMOL

conda install conda-forge::pymol-open-source

Note: If PyMOL fails due to missing libnetcdf.so, install:

conda install -c conda-forge libnetcdf==4.7.3

muscle (Multiple Sequence Alignment)

conda install bioconda::muscle

UCSF Chimera

1. Download the latest version of UCSF Chimera (64-bit recommended)
2. Make the binary executable and run the installer:

   cd ~/Downloads  # or wherever you downloaded the file
   chmod +x chimera*.bin
   ./chimera*.bin

3. Follow the installation prompts, preferably creating a symlink in a directory in your $PATH

Note: ColBuilder specifically requires UCSF Chimera, not the newer ChimeraX.

Modeller

1. Download Modeller version 10.5
2. Follow the installation instructions provided
3. Add the following environment variables to your .bashrc or .bash_profile:

   export PYTHONPATH="/home/user/bin/modeller10.5/lib/x86_64-intel8/python3.3:$PYTHONPATH"
   export PYTHONPATH="/home/user/bin/modeller10.5/modlib:$PYTHONPATH"
   export LD_LIBRARY_PATH="/home/user/bin/modeller10.5/lib/x86_64-intel8:$LD_LIBRARY_PATH"

   (Adjust paths according to your installation location)

🚀 Quick Start

To verify your installation and run a basic example:

1. Verify installation:

   colbuilder --help

2. Create a basic configuration file (save as config.yaml):

   # Basic human collagen microfibril configuration   
   species: "homo_sapiens"
   sequence_generator: true
   geometry_generator: true
   crosslink: true
   fibril_length: 60.0
   contact_distance: 20
   n_term_type: "HLKNL"
   c_term_type: "HLKNL"
   n_term_combination: "9.C - 947.A"
   c_term_combination: "1047.C - 104.C"

3. Run ColBuilder:

   colbuilder --config_file config.yaml

⚙️ Operation Modes & Workflow

ColBuilder operates through modular modes, each responsible for a different part of the collagen model-building pipeline. These modes can be combined in various ways or run separately using different configuration files.

🧠 Understanding PDB Types

ColBuilder produces or requires two kinds of PDB files:

• Collagen triple helix molecule PDB: A single ~300 nm-long collagen molecule (usually with specified crosslink residues). Output of Mode 1, input to Modes 2 and 4.
• Collagen fibril PDB: A full microfibril model composed of multiple triple helices arranged based on crystal geometry, length, and crosslinking. Output of Modes 2, 4, or 5, input to Modes 3 and 5.

Understanding this distinction is crucial for organizing your workflow correctly.

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📊 Mode Summary Table

#	Mode	Purpose	Input(s)	Output	Can Run With Other Modes?
1	sequence_generator	Generate a collagen triple helix molecule via homology modeling	species or custom FASTA	Triple helix PDB	Yes: with 2, 3, 5
2	geometry_generator	Assemble a collagen fibril from a single triple helix	PDB from Mode 1 or custom PDB	Fibril PDB	Yes: with 1, 3, 5
3	topology_generator	Generate topology files for GROMACS simulations	Fibril PDB (from Mode 2, 4, or 5)	.top, .itp, .gro	Yes: with 2, 4, 5
3*	topology_generator (topology-only)	Generate topology files from an existing fibril PDB without geometry generation	Pre-existing fibril PDB with crosslinks	.top, .itp, .gro	No, standalone mode
4	mix_bool	Generate a fibril by mixing multiple crosslink types	Two (or more) triple helix PDBs from Mode 1	Mixed fibril PDB	No, requires separate script
5	replace_bool	Replace crosslinks in an existing fibril	Fibril PDB from Mode 2 or 4	Modified fibril PDB	Yes: with 2, 3

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🔁 Valid Mode Combinations

These combinations can be run in a single config file:

# Example combination
sequence_generator: true
geometry_generator: true         # (optional)
topology_generator: true         # (optional)
replace_bool: true               # (optional)

✅ Valid Workflows

These mode combinations can be run in a single configuration file:

• ✅ 1 + 2 - Generate molecule and build fibril
• ✅ 1 + 2 + 3 - Complete pipeline: molecule → fibril → topology - example1
• ✅ 2 + 3 - Build fibril and topology from custom triple helix PDB
• ✅ 1 + 2 + 5 - Generate, build, then replace crosslinks
• ✅ 1 + 2 + 5 + 3 - Generate, build, replace crosslinks by their standard amino acid, then create topology
• ✅ 2 + 5 - Build fibril then replace crosslinks - example3
• ✅ 2 + 5 + 3 - Build fibril, replace crosslinks, then create topology
• ✅ 3 - Topology-only mode: generate topology from existing fibril PDB - example4

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🔧 Mode 4 (Mixing Crosslinks): Run Separately via Script

Mixing crosslinks (Mode 4) currently requires a separate workflow using (at least) two config files for triple helix generation and one for fibril construction (and optional topology generation):

example2

# Example bash script for mixing crosslinks
colbuilder --config_file triple_helix_A.yaml
colbuilder --config_file triple_helix_B.yaml
colbuilder --config_file mix_geometry.yaml   # sets mix_bool: true and includes both PDBs

You can also chain this with replace_bool (Mode 5) or topology_generator (Mode 3) in the third config.

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🔗 Collagen Crosslinks

ColBuilder supports a comprehensive range of collagen crosslinks, including both enzymatic and non-enzymatic types. Crosslinks are critical for collagen stability and mechanical properties.

Enzymatic Crosslinks

Enzymatic crosslinks are formed through lysyl oxidase (LOX) activity and mature through various pathways:

Divalent Crosslinks (2 residues):

• HLKNL (Hydroxy-lysinonorleucine) - Mature divalent, most common
• LKNL (Lysinonorleucine) - Immature divalent
• deHLNL (Dehydro-hydroxylysinonorleucine) - Immature precursor
• deHHLNL (Dehydro-dihydroxylysinonorleucine) - Immature precursor

Trivalent Crosslinks (3 residues):

• PYD (Pyridinoline) - Hydroxylysine-derived, most common trivalent
• DPD (Deoxypyridinoline) - Lysine-derived trivalent
• PYL (Pyrrole) - Alternative trivalent pathway
• DPL (Deoxypyrrole) - Alternative trivalent pathway

Non-Enzymatic Crosslinks (AGEs)

Advanced Glycation End-products form spontaneously and accumulate with aging:

• Pentosidine
• Glucosepane
• MOLD (Methylglyoxal-lysine dimer) - Glycation-derived crosslink

Crosslink Combinations

Crosslinks form at specific positions in the collagen molecule:

Terminal Crosslinks:

• N-terminal: Typically at positions 9 and 947 (or species-equivalent)
• C-terminal: Typically at positions 1047 and 104 (or species-equivalent)

Divalent combinations (2 residues):

n_term_combination: "9.C - 947.A"
c_term_combination: "1047.C - 104.C"

Trivalent combinations (3 residues):

# PYD crosslink example
n_term_combination: "6.B - 9.C - 946.A"
c_term_combination: "1046.C - 1046.A - 103.C"

Note: Residue positions may vary slightly between species. See crosslinks.csv for species-specific combinations.

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📖 Usage Guide

Basic Usage

The general syntax for running ColBuilder is:

colbuilder --config_file config.yaml [OPTIONS]

Configuration Options

ColBuilder uses YAML configuration files to define parameters. Here's a complete template with all available options:

# ================================================================================
# ColBuilder Configuration File
# ================================================================================
# The pipeline consists of three main modules that can be run 
# independently or in combination:
#
# 1. SEQUENCE GENERATOR: Creates collagen triple helix structures from sequences
# 2. GEOMETRY GENERATOR: Builds collagen microfibrils from triple helices
# 3. TOPOLOGY GENERATOR: Generates force field topologies for simulations
#
# IMPORTANT: When using additional crosslinks with a pre-mutated PDB, 
# e.g. to add AGE crosslinks:
# - Run sequence generation first to apply and optimize additional crosslinks
# - Then run geometry generation in a separate execution using the output PDB
# ================================================================================

# Operation Mode
mode: null
config_file: null            # Path to another config file (for nested configs)  
sequence_generator: true     # Generate triple helix structure from sequence
geometry_generator: true     # Build microfibril from triple helix
topology_generator: false    # Generate simulation topology files
debug: false                 # Keep intermediate files for debugging
working_directory: "./"      # Directory for output files

# ================================================================================
# SEQUENCE GENERATION SETTINGS
# ================================================================================
# These settings control the generation of collagen triple helix structures.
# Two main workflows are supported:
# 1. Standard: Generate from FASTA sequence (leave mutated_pdb as null)
# 2. Mutated PDB: Add crosslinks to existing structure (must provide mutated_pdb)

# Species selection
species: "homo_sapiens"
# Available species options:
# Mammals (Primates): homo_sapiens, pan_troglodytes, pongo_abelii, callithrix_jacchus, otolemur_garnettii
# Mammals (Rodents): mus_musculus, rattus_norvegicus
# Mammals (Other): bos_taurus, canis_lupus, ailuropoda_melanoleuca, mustela_putorius, myotis_lucifugus, loxodonta_africana
# Fish: danio_rerio, oreochromis_niloticus, oryzias_latipes, tetraodon_nigroviridis, xiphophorus_maculatus
# Reptiles: pelodiscus_sinensis

# Mutated PDB workflow - provide pre-optimized structure to add additional crosslinks
mutated_pdb: null  # Path to pre-mutated PDB, or null for standard workflow
# Example: "rattusnorvegicus_N_PYD_C_PYD+ADD1_Glucosepane.pdb"

# Custom sequence input - overrides species selection if provided
fasta_file: null  # Path to custom FASTA file, or null to use available species sequence
# Example: "path/to/custom_sequence.fasta"

# ================================================================================
# CROSSLINK CONFIGURATION
# ================================================================================
# Terminal crosslinks are applied at N and C termini during standard generation.
# Additional crosslinks can be added anywhere (e.g., AGE products).

crosslink: true  # Enable crosslink application and optimization

# Terminal crosslinks (standard sequence generation)
n_term_type: "HLKNL"               # N-terminal crosslink type
c_term_type: "HLKNL"               # C-terminal crosslink type
n_term_combination: "9.C - 947.A"  # Format: "resid.chain - resid.chain"
c_term_combination: "1047.C - 104.C"

# Available crosslink types:
# Enzymatic Divalent: "HLKNL", "LKNL", "deHLNL", "deHHLNL"
# Enzymatic Trivalent: "PYD", "DPD", "PYL", "DPL" (3 residues required)
# Non-Enzymatic (AGE): "Pentosidine", "Glucosepane", "MOLD"

# Trivalent crosslink example (requires 3 residues):
# n_term_combination: "6.B - 9.C - 946.A"
# c_term_combination: "1046.C - 1046.A - 103.C"

# Additional crosslinks (for mutated PDB workflow)
# Uncomment to add crosslinks on top of existing structure:
# additional_1_type: "Pentosidine"
# additional_1_combination: "1008.A - 767.B"
# additional_2_type: null  # Optional second additional crosslink
# additional_2_combination: null

# Crosslink optimization settings
# crosslink_copies: ["D0", "D5"]  # Periodic copies for optimization, must be exactly 2 elements
# Options: D0-D5, D0-D1, D1-D2, D2-D3, D3-D4. If not specified, default is ["D0", "D5"]

# ================================================================================
# GEOMETRY GENERATION SETTINGS
# ================================================================================
# These settings control microfibril assembly from triple helices.
# The geometry generator arranges multiple copies of the input structure
# into a collagen microfibril based on crystal contacts.

# Input structure for geometry generation
pdb_file: null  # Path to input PDB, or null if sequence_generator is true
# IMPORTANT: When using additional crosslinks, run sequence generation 
# separately first, then use its output here

# Microfibril parameters
contact_distance: 20      # Maximum distance (Å) for crystal contacts
fibril_length: 70.0       # Target length of microfibril (nm)

# Advanced geometry options (usually left as null/false)
crystalcontacts_file: null      # Custom crystal contacts file
connect_file: null              # Custom connectivity information
crystalcontacts_optimize: false # Optimize crystal contacts
# Note: crystalcontacts_optimize is automatically true when using contact_distance

# ================================================================================
# MIXING OPTIONS
# ================================================================================
# Create heterogeneous microfibrils with different crosslink types.

mix_bool: false           # Enable mixing of different crosslink types
ratio_mix: "D:80 T:20"    # Ratio of each type (must sum to 100)
# Format: "TypeLabel:percentage TypeLabel:percentage"
# Example: "D:80 T:20" = 80% divalent, 20% trivalent
files_mix:  # PDB files for each crosslink type (required if mix_bool=true)
  - "collagen-molecule-crosslinkA.pdb"  # File for first type
  - "collagen-molecule-crosslinkB.pdb"  # File for second type
# Note: Labels (D, T, etc.) are arbitrary but must match ratio_mix

# ================================================================================
# REPLACEMENT OPTIONS
# ================================================================================
# Reduce crosslink density by replacing some with standard amino acids.
# Useful for modeling aged or diseased tissue with fewer crosslinks.

replace_bool: false      # Enable crosslink replacement
ratio_replace: 30        # Percentage of crosslinks to replace (0-100)
replace_file: null       # Input file, or null to use geometry output

# ================================================================================
# TOPOLOGY GENERATION SETTINGS
# ================================================================================
# Generate molecular dynamics topology files for the final structure.

force_field: "amber99"  # Force field to use
# Options: "amber99" (all-atom), "martini3" (coarse-grained)

topology_debug: false   # Save intermediate topology files

# Topology-Only Mode
# When topology_generator: true AND both sequence_generator: false and 
# geometry_generator: false, ColBuilder operates in topology-only mode,
# reading an existing fibril PDB and generating topology files without 
# running geometry generation. Crosslink parameters must match the input PDB.

For a complete list of configuration options, see the detailed documentation.

Example Workflows

Creating a Basic Human Collagen Microfibril

# config_human_basic.yaml
species: "homo_sapiens"
sequence_generator: true
geometry_generator: true
crosslink: false
fibril_length: 40.0
contact_distance: 25

colbuilder --config_file config_human_basic.yaml

Generating a Crosslinked Bovine Microfibril

# config_bovine_crosslinked.yaml
species: "bos_taurus"
sequence_generator: true
geometry_generator: true
crosslink: true
n_term_type: "HLKNL"
c_term_type: "HLKNL"
n_term_combination: "9.C - 946.A"
c_term_combination: "1046.C - 103.C"
fibril_length: 80.0
contact_distance: 15

colbuilder --config_file config_bovine_crosslinked.yaml

Creating a Mixed Crosslinked (80% Divalent + 20% Trivalent) Human Collagen Microfibril from Collagen Molecules

First, generate the two crosslink types:

# config_divalent_molecule.yaml
species: "homo_sapiens"
sequence_generator: true
geometry_generator: false
crosslink: true
n_term_type: "HLKNL"
c_term_type: "HLKNL"
n_term_combination: "9.C - 947.A"
c_term_combination: "1047.C - 104.C"

# config_trivalent_molecule.yaml
species: "homo_sapiens"
sequence_generator: true
geometry_generator: false
crosslink: true
n_term_type: "PYD"
c_term_type: "PYD"
n_term_combination: "6.B - 9.C - 946.A"
c_term_combination: "1046.C - 1046.A - 103.C"

Then mix them:

# config_mixed_crosslinks.yaml
sequence_generator: false
geometry_generator: true
contact_distance: 25
fibril_length: 40.0
mix_bool: true
ratio_mix: "D:80 T:20"
files_mix:
 - "homo_sapiens_N_HLKNL_C_HLKNL.pdb"
 - "homo_sapiens_N_PYD_C_PYD.pdb"

colbuilder --config_file config_divalent_molecule.yaml
colbuilder --config_file config_trivalent_molecule.yaml
colbuilder --config_file config_mixed_crosslinks.yaml

Generating a Coarse-Grained Topology File for MD Simulation

# config_topology.yaml
species: "homo_sapiens"
sequence_generator: false
geometry_generator: true
topology_generator: true
pdb_file: "path/to/template_collagen_molecule.pdb"
contact_distance: 30
fibril_length: 40.0
force_field: "martini3"

colbuilder --config_file config_topology.yaml

Generating Topology Files from an Existing Fibril (Topology-Only Mode)

If you already have a complete fibril PDB file (e.g., from a previous ColBuilder run or from another source) and only need to generate topology files for simulation:

# config_topology_only.yaml
species: "homo_sapiens"
sequence_generator: false
geometry_generator: false
topology_generator: true
pdb_file: "path/to/existing_fibril.pdb"
crosslink: true
n_term_type: "PYD"
c_term_type: "PYD"
n_term_combination: "6.B - 9.C - 946.A"
c_term_combination: "1046.C - 1046.A - 103.C"
force_field: "amber99"

colbuilder --config_file config_topology_only.yaml

Important notes for topology-only mode:

• The input PDB must be a complete fibril (not a single triple helix)
• Crosslink information must match what's present in the PDB file
• The tool will automatically detect model connectivity from crosslink positions
• Works with fibrils containing divalent (D), trivalent (T), or mixed (M) crosslinks
• Supports both Amber99 and Martini3 force fields

Creating a Fibril with PYD Crosslinks

PYD (Pyridinoline) is a trivalent crosslink requiring three residues:

# config_pyd_fibril.yaml
species: "rattus_norvegicus"
sequence_generator: true
geometry_generator: true
crosslink: true
n_term_type: "PYD"
c_term_type: "PYD"
n_term_combination: "6.B - 9.C - 946.A"
c_term_combination: "1046.C - 1046.A - 103.C"
fibril_length: 40.0
contact_distance: 20

colbuilder --config_file config_pyd_fibril.yaml

Replacing Crosslinks in an Existing Fibril

Reduce crosslink density by replacing a percentage with lysine:

# config_replace_crosslinks.yaml
species: "homo_sapiens"
sequence_generator: false
geometry_generator: true
pdb_file: "homo_sapiens_N_HLKNL_C_HLKNL.pdb"
crosslink: true
n_term_type: "HLKNL"
c_term_type: "HLKNL"
n_term_combination: "9.C - 947.A"
c_term_combination: "1047.C - 104.C"
replace_bool: true
ratio_replace: 30  # Replace 30% of crosslinks
fibril_length: 40.0
contact_distance: 20

colbuilder --config_file config_replace_crosslinks.yaml

Adding AGE Crosslinks to an Existing Structure (Mutated PDB Workflow)

Add non-enzymatic crosslinks (AGEs) on top of existing enzymatic crosslinks. Examples for this workflow can be found in docs/examples/example5:

• Sequence + Geometry + Topology generation for a collagen with a mixture of PYD and Glucosepane crosslinks example5.1
• Sequence + Geometry + Replacement generation for a collagen with a mixture PYD and Glucosepane crosslinks example5.2
• Sequence + Geometry + Mixing + Topology generation for different crosslink combinations example5.3

In general, the most basic workflow happens in three steps:

Step 1: Generate base structure with enzymatic crosslinks

# config_add_age_step1.yaml
species: "rattus_norvegicus"
sequence_generator: true
geometry_generator: false
topology_generator: false
crosslink: true

# Base terminal crosslinks
n_term_type: "PYD"
c_term_type: "PYD"
n_term_combination: "6.B - 9.C - 946.A"
c_term_combination: "1046.C - 1046.A - 103.C"

Step 2: Add AGE crosslinks to the output of step 1:

# config_add_age_step2.yaml
species: "rattus_norvegicus"
sequence_generator: true
geometry_generator: false
topology_generator: false

mutated_pdb: "rattusnorvegicus_N_PYD_C_PYD.pdb"

crosslink: true
# Terminal crosslinks must match step 1
n_term_type: "PYD"
c_term_type: "PYD"
n_term_combination: "6.B - 9.C - 946.A"
c_term_combination: "1046.C - 1046.A - 103.C"

# Add Glucosepane AGE crosslink
additional_1_type: "Glucosepane"
additional_1_combination: "1055.C - 822.A"

# Customize crosslink optimization
crosslink_copies: ["D2", "D3"]

Step 3: Build fibril using the output from step 2:

# config_add_age_step3.yaml
species: "rattus_norvegicus"
sequence_generator: false
geometry_generator: true
topology_generator: true

crosslink: true
n_term_type: "PYD"
c_term_type: "PYD"
n_term_combination: "6.B - 9.C - 946.A"
c_term_combination: "1046.C - 1046.A - 103.C"

# Use output from step 2
pdb_file: "rattusnorvegicus_N_PYD_C_PYD+ADD1_Glucosepane.pdb"

# Fibril parameters
fibril_length: 40.0
contact_distance: 20
force_field: "amber99"

# Run in three steps
colbuilder --config_file config_add_age_step1.yaml
colbuilder --config_file config_add_age_step2.yaml
colbuilder --config_file config_add_age_step3.yaml

Why three steps? The mutated PDB workflow requires separate execution to properly optimize the additional crosslinks before building the fibril geometry.

📚 Documentation

For detailed API documentation, advanced usage examples, and theoretical background:

• User Guide
• Configuration Reference
• Data Reference
• Data Dictionary
• Example Gallery

🤝 Contributing

We welcome contributions to ColBuilder! Please see our contributing guidelines for details on how to submit issues, pull requests, and code reviews.

📚 Publications & Citation

If you use ColBuilder in your research, please cite our paper:

https://academic.oup.com/bioinformatics/article/41/6/btaf278/8125020

A BibTeX entry is provided in the CITATION.bibtex file.

If you perform coarse-grained simulations, please also cite the Martini 3 paper for collagen fibrils:

https://www.cell.com/biophysj/fulltext/S0006-3495(25)00663-0

🙏 Acknowledgements

ColBuilder is developed and maintained by the Gräter group at the Max Planck Institute for Polymer Research. We thank all contributors that have supported this work.

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For questions, feedback, or support, please open an issue on our GitHub repository.