[
    {
    "name": "ptr",
    "ref_file": "./examples/ptr_design/1SPS.pdb",
    "chains": [
    {
        "chain_type": "proteinChain",
        "sequence": "F/-2-4"
    },
    {
        "chain_type": "proteinChain",
        "sequence": "100-110"
    }
    ],
    "hotspot": "F/0",
    "center_method": "hotspot_center"
  }
]