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Overview

Binder specifications define the protein binder properties (modality, structure, design regions) that will be used to generate candidates.

Creating a New Binder Specification

Nanobody specification structure selection
  1. From your project dashboard, click ”+ Add” in the Binder Specifications section.
  2. Step 1: Setup - Give your binder specification a name and choose the protein modality:

    Peptide

    Design short peptide sequences

    Antibody

    Create antibody heavy and light chains

    Nanobody

    Design single-domain antibodies

    Other

    Other protein types
  3. Click ”> Continue to Specification”.

Starting Specification

Option 1: Structure-Based Specification

Nanobody specification structure selection
Select a template:
  • Choose from pre-loaded structures (e.g., vWF A1-Caplacizumab Complex, IL-6R-Vobarilizumab Complex)
  • Each template shows PDB ID and description
Or import your own:
  • Enter a PDB ID and Assembly ID (default: 1), then click “Import”
  • Or upload a structure file (.cif, .cif.gz, etc.)

Option 2: Sequence-Based Specification

Click the “Sequence” tab to add sequences directly instead of using a structure.

Select Residues

Select residues for nanobody specification
Select the residues you want to include in your design:
  • Recommended: ≤300 residues
  • Use CDR1, CDR2, CDR3 quick-select buttons for antibodies/nanobodies
  • Or manually select by clicking and dragging on the sequence
  • Selected residues are highlighted in green
  • The 3D structure updates to show selected regions
Numbering schemes:
  • Chothia (default) or Kabat numbering for antibodies/nanobodies
  • Switch between schemes using the tabs above the sequence
Click ”> Continue to Design” when done.

Design Configuration

Configure design motifs and constraints:
Nanobody specification structure selection

Excluded Amino Acids

Specify amino acids that will not be used in designed regions (e.g., exclude Cysteine to prevent unwanted disulfide bonds).
Nanobody specification structure selection

Create Design Motifs

  1. Select residues on the sequence or 3D structure
  2. Right-click or use the context menu to “Replace with design motif”
  3. For CDR regions, you can specify:
    • Fixed length - Replace with same number of residues
    • Variable length - Specify a range (e.g., 10-25 residues for CDR3)
Nanobody specification structure selection
Nanobody specification structure selection
Nanobody specification structure selection

Motif Management

  • Each motif is color-coded and shown in the sequence viewer
  • Click a motif to edit it
  • Click the X on a motif to remove it
  • Summary shows total residues and number of motifs
Click ”> Create Specification” when ready.

After Binder Specification Creation

Once your binder specification is created, you’ll see options to:
  • Generate binders with AI - Start a virtual screen using this binder specification
  • Create Another Target - Add another target to design binders against
  • Skip for now - Continue later