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{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "view-in-github",
        "colab_type": "text"
      },
      "source": [
        "<a href=\"https://colab.research.google.com/github/sokrypton/ColabDesign/blob/v1.1.1/af/examples/af_pseudo_diffusion_dgram.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "VD9K5H2cnFxL"
      },
      "source": [
        "#AF_pseudo_diffusion + proteinMPNN\n",
        "Hacking AlphaFold to be a diffusion model (for backbone generation) via distogram. At each step add logits from proteinMPNN.\n",
        "\n",
        "\n",
        "**WARNING**: This notebook is experimental, designed as a control. Not intended for practical use at this stage."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "cellView": "form",
        "id": "YCRzPGdTZfEe"
      },
      "outputs": [],
      "source": [
        "#@title setup\n",
        "%%time\n",
        "import os\n",
        "if not os.path.isdir(\"params\"):\n",
        "  # get code\n",
        "  os.system(\"pip -q install git+https://github.com/sokrypton/ColabDesign.git@v1.1.1\")\n",
        "  # for debugging\n",
        "  os.system(\"ln -s /usr/local/lib/python3.*/dist-packages/colabdesign colabdesign\")\n",
        "  # download params\n",
        "  os.system(\"mkdir params\")\n",
        "  os.system(\"apt-get install aria2 -qq\")\n",
        "  os.system(\"aria2c -q -x 16 https://storage.googleapis.com/alphafold/alphafold_params_2022-12-06.tar\")\n",
        "  os.system(\"tar -xf alphafold_params_2022-12-06.tar -C params\")\n",
        "\n",
        "import warnings\n",
        "warnings.simplefilter(action='ignore', category=FutureWarning)\n",
        "\n",
        "import os, re\n",
        "from colabdesign import mk_afdesign_model, clear_mem\n",
        "from colabdesign.mpnn import mk_mpnn_model\n",
        "from colabdesign.af.alphafold.common import residue_constants\n",
        "from colabdesign.shared.protein import _np_get_cb\n",
        "\n",
        "from IPython.display import HTML\n",
        "from google.colab import files\n",
        "import numpy as np\n",
        "import jax.numpy as jnp\n",
        "import jax\n",
        "from scipy.special import softmax\n",
        "\n",
        "import tqdm.notebook\n",
        "TQDM_BAR_FORMAT = '{l_bar}{bar}| {n_fmt}/{total_fmt} [elapsed: {elapsed} remaining: {remaining}]'\n",
        "\n",
        "def get_pdb(pdb_code=\"\"):\n",
        "  if pdb_code is None or pdb_code == \"\":\n",
        "    upload_dict = files.upload()\n",
        "    pdb_string = upload_dict[list(upload_dict.keys())[0]]\n",
        "    with open(\"tmp.pdb\",\"wb\") as out: out.write(pdb_string)\n",
        "    return \"tmp.pdb\"\n",
        "  elif os.path.isfile(pdb_code):\n",
        "    return pdb_code\n",
        "  elif len(pdb_code) == 4:\n",
        "    os.system(f\"wget -qnc https://files.rcsb.org/view/{pdb_code}.pdb\")\n",
        "    return f\"{pdb_code}.pdb\"\n",
        "  else:\n",
        "    os.system(f\"wget -qnc https://alphafold.ebi.ac.uk/files/AF-{pdb_code}-F1-model_v3.pdb\")\n",
        "    return f\"AF-{pdb_code}-F1-model_v3.pdb\"\n",
        "\n",
        "def sample_gumbel(shape, eps=1e-20): \n",
        "  \"\"\"Sample from Gumbel(0, 1)\"\"\"\n",
        "  U = np.random.uniform(size=shape)\n",
        "  return -np.log(-np.log(U + eps) + eps)"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "wxYMB4A9Zmrf",
        "cellView": "form"
      },
      "outputs": [],
      "source": [
        "#@title initialize the model\n",
        "length = 100 #@param {type:\"integer\"}\n",
        "#symmetry = \"C\" #@param [\"C\"]\n",
        "#copies = 1 #@param {type:\"integer\"}\n",
        "#@markdown Provide a starting point (optional)\n",
        "starting_seq = \"\" #@param {type:\"string\"}\n",
        "starting_seq = re.sub(\"[^A-Z]\", \"\", starting_seq.upper())\n",
        "#@markdown - if `starting_seq` provided the `length` option will be overwritten by length of starting sequence.\n",
        "\n",
        "#@markdown Experimental options\n",
        "use_multimer = False \n",
        "mode = \"dgram_retrain\" #@param [\"dgram\",\"dgram_retrain\"]\n",
        "##@markdown - `xyz` - use structure output as template input\n",
        "#@markdown - `dgram` - use distogram output as template input\n",
        "#@markdown - `dgram_retrain` - replace distogram head from AlphaFold with one retrained to map output bins to template bins.\n",
        "\n",
        "if len(starting_seq) > 0:\n",
        "  length = len(starting_seq)\n",
        "\n",
        "clear_mem()\n",
        "af_model = mk_afdesign_model(protocol=\"hallucination\",\n",
        "                             use_templates=True,\n",
        "                             debug=True, \n",
        "                             use_multimer=use_multimer)\n",
        "af_model.prep_inputs(length=length)\n",
        "mpnn_model = mk_mpnn_model()\n",
        "print(\"lengths\",af_model._lengths)\n",
        "\n",
        "if \"dgram\" in mode:\n",
        "  if \"retrain\" in mode and not use_multimer:\n",
        "    # update distogram head to return all 39 bins\n",
        "    af_model._cfg.model.heads.distogram.first_break = 3.25\n",
        "    af_model._cfg.model.heads.distogram.last_break = 50.75\n",
        "    af_model._cfg.model.heads.distogram.num_bins = 39\n",
        "    af_model._model = af_model._get_model(af_model._cfg)\n",
        "    from colabdesign.af.weights import __file__ as af_path\n",
        "    template_dgram_head = np.load(os.path.join(os.path.dirname(af_path),'template_dgram_head.npy'))\n",
        "    for k in range(len(af_model._model_params)):\n",
        "      params = {\"weights\":jnp.array(template_dgram_head[k]),\"bias\":jnp.zeros(39)}\n",
        "      af_model._model_params[k][\"alphafold/alphafold_iteration/distogram_head/half_logits\"] = params\n",
        "  else:\n",
        "    dgram_map = np.eye(39)[np.repeat(np.append(0,np.arange(15)),4)]\n",
        "    dgram_map[-1,:] = 0 \n",
        "\n",
        "def get_dgram(positions, num_bins=39, min_bin=3.25, max_bin=50.75):\n",
        "  atom_idx = residue_constants.atom_order\n",
        "  atoms = {k:positions[...,atom_idx[k],:] for k in [\"N\",\"CA\",\"C\"]}\n",
        "  cb = _np_get_cb(**atoms, use_jax=False)\n",
        "  dist2 = np.square(cb[None,:] - cb[:,None]).sum(-1,keepdims=True)\n",
        "  lower_breaks = np.linspace(min_bin, max_bin, num_bins)\n",
        "  lower_breaks = np.square(lower_breaks)\n",
        "  upper_breaks = np.concatenate([lower_breaks[1:],np.array([1e8], dtype=jnp.float32)], axis=-1)\n",
        "  return ((dist2 > lower_breaks) * (dist2 < upper_breaks)).astype(float)"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "3Dt8i00UbxtW",
        "cellView": "form"
      },
      "outputs": [],
      "source": [
        "#@title run protocol\n",
        "#@markdown Optimization options\n",
        "iterations = 100 #@param [\"50\", \"100\"] {type:\"raw\"}\n",
        "use_dgram_noise = True #@param {type:\"boolean\"}\n",
        "use_seq_noise = True #@param {type:\"boolean\"}\n",
        "use_dropout = True #@param {type:\"boolean\"}\n",
        "seqsep_mask = 6 #@param {type:\"integer\"}\n",
        "\n",
        "#@markdown AlphaFold options\n",
        "sample_models = True #@param {type:\"boolean\"}\n",
        "num_recycles = 0 #@param [\"0\", \"1\", \"2\", \"3\"] {type:\"raw\"}\n",
        "\n",
        "#@markdown proteinMPNN options (set to `none` to disable)\n",
        "mpnn_mode = \"conditional\" #@param [\"none\",\"sample\", \"conditional\", \"unconditional\"]\n",
        "\n",
        "L = sum(af_model._lengths)\n",
        "af_model.restart(mode=\"gumbel\")\n",
        "af_model._inputs[\"rm_template_seq\"] = True\n",
        "\n",
        "# gather info about inputs\n",
        "if \"offset\" in af_model._inputs:\n",
        "  offset = af_model._inputs\n",
        "else:\n",
        "  idx = af_model._inputs[\"residue_index\"]\n",
        "  offset = idx[:,None] - idx[None,:]\n",
        "\n",
        "# initialize sequence\n",
        "if len(starting_seq) > 1:\n",
        "  af_model.set_seq(seq=starting_seq)\n",
        "af_model._inputs[\"bias\"] = np.zeros((L,20))\n",
        "\n",
        "# initialize coordinates/dgram\n",
        "af_model._inputs[\"batch\"] = {\"aatype\":np.zeros(L).astype(int),\n",
        "                             \"all_atom_mask\":np.zeros((L,37)),\n",
        "                             \"all_atom_positions\":np.zeros((L,37,3)),\n",
        "                             \"dgram\":np.zeros((L,L,39))}\n",
        "\n",
        "for k in range(iterations):\n",
        "\n",
        "  # disable stochastic part for the last 10 steps\n",
        "  if k > (iterations - 10):\n",
        "    use_dropout = False\n",
        "    sample_models = False\n",
        "    use_seq_noise = False\n",
        "    seqsep_mask = 0.0\n",
        "\n",
        "  # noise\n",
        "  if k > 0:\n",
        "    dgram_xyz = get_dgram(xyz)\n",
        "    dgram_prob = softmax(dgram_logits,-1)\n",
        "\n",
        "    if use_seq_noise:\n",
        "      af_model._inputs[\"bias\"] = 0.1 * sample_gumbel((L,20))\n",
        "\n",
        "    if mode == \"xyz\":\n",
        "      dgram = dgram_xyz\n",
        "    if mode == \"dgram\":\n",
        "      dgram = dgram_prob @ dgram_map\n",
        "      dgram[...,14:] = dgram_xyz[...,14:] * dgram_prob[...,-1:]\n",
        "    if mode == \"dgram_retrain\":\n",
        "      dgram = dgram_prob\n",
        "    \n",
        "    if use_dgram_noise:\n",
        "      noise = sample_gumbel(dgram.shape) * (1 - k/iterations)\n",
        "      dgram = softmax(np.log(dgram + 1e-8) + noise, -1)\n",
        "\n",
        "    # add mask to avoid local contacts being fixed (otherwise there is a bias toward helix)\n",
        "    mask = np.abs(offset) > seqsep_mask\n",
        "    af_model._inputs[\"batch\"][\"dgram\"] = dgram * mask[:,:,None]\n",
        "\n",
        "  # denoise\n",
        "  aux = af_model.predict(return_aux=True, verbose=False,\n",
        "                         sample_models=sample_models,\n",
        "                         dropout=use_dropout, num_recycles=num_recycles)\n",
        "  plddt = aux[\"plddt\"]\n",
        "  seq = aux[\"seq\"][\"hard\"][0].argmax(-1)\n",
        "  xyz = aux[\"atom_positions\"].copy()\n",
        "  dgram_logits = aux[\"debug\"][\"outputs\"][\"distogram\"][\"logits\"] \n",
        "  \n",
        "  # update inputs    \n",
        "  af_model._inputs[\"batch\"][\"aatype\"] = seq\n",
        "  af_model._inputs[\"batch\"][\"all_atom_mask\"][:,:4] = np.sqrt(plddt)[:,None]\n",
        "  af_model._inputs[\"batch\"][\"all_atom_positions\"] = xyz\n",
        "\n",
        "  # add logits from proteinmpnn at each stage\n",
        "  if mpnn_mode != \"none\":\n",
        "    mpnn_model.get_af_inputs(af_model)\n",
        "    if mpnn_mode == \"sample\":\n",
        "      mpnn_out = mpnn_model.sample(temp = 1-k/iterations)\n",
        "      mpnn_logits = mpnn_out[\"logits\"][0,:,:20]\n",
        "      aux[\"log\"][\"mpnn\"] = mpnn_out[\"score\"][0]\n",
        "    else:\n",
        "      opt = {} if mpnn_mode == \"conditional\" else {\"ar_mask\":np.zeros((L,L))}\n",
        "      mpnn_out = mpnn_model.score(**opt)\n",
        "      mpnn_logits = mpnn_out[\"logits\"][:,:20]\n",
        "      aux[\"log\"][\"mpnn\"] = mpnn_out[\"score\"]\n",
        "    \n",
        "    beta = np.square(k/iterations) * plddt[:,None]\n",
        "    af_model._params[\"seq\"] = (1-beta) * af_model._params[\"seq\"] + beta * mpnn_logits\n",
        "\n",
        "  # save results\n",
        "  af_model._save_results(aux)\n",
        "  af_model._k += 1"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "af_model.save_pdb(\"0.pdb\")\n",
        "af_model.plot_pdb()\n",
        "af_model.get_seqs()"
      ],
      "metadata": {
        "id": "YeYD4KF8MUA_"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "6cJhizcYcUxm"
      },
      "outputs": [],
      "source": [
        "HTML(af_model.animate(dpi=100))"
      ]
    },
    {
      "cell_type": "code",
      "source": [
        "#@title sample new sequences using proteinMPNN and rescore with alphafold (w/o template)\n",
        "#@markdown #### Design Options\n",
        "num_seqs = 32 #@param [\"32\", \"64\", \"128\", \"256\", \"512\", \"1024\"] {type:\"raw\"}\n",
        "sampling_temp = 0.1 \n",
        "import pandas as pd\n",
        "from google.colab import data_table\n",
        "data_table.enable_dataframe_formatter()\n",
        "\n",
        "# zero out template inputs\n",
        "out = mpnn_model.sample(num=num_seqs//32, batch=32,\n",
        "                        temperature=sampling_temp)\n",
        "af_terms = [\"plddt\",\"ptm\",\"pae\"]\n",
        "for k in af_terms: out[k] = []\n",
        "os.system(\"mkdir -p output/all_pdb\")\n",
        "\n",
        "af_model._inputs[\"batch\"][\"dgram\"] = np.zeros((L,L,39))\n",
        "with tqdm.notebook.tqdm(total=out[\"S\"].shape[0], bar_format=TQDM_BAR_FORMAT) as pbar:\n",
        "  with open(\"design.fasta\",\"w\") as fasta:\n",
        "    for n in range(num_seqs):\n",
        "      seq = out[\"seq\"][n]\n",
        "      af_model.predict(seq=seq,\n",
        "                      num_recycles=1,\n",
        "                      num_models=1,\n",
        "                      verbose=False)\n",
        "\n",
        "      for t in af_terms:\n",
        "        out[t].append(af_model.aux[\"log\"][t])\n",
        "      out[\"pae\"][-1] = out[\"pae\"][-1] * 31\n",
        "      af_model._save_results(save_best=True, verbose=False)\n",
        "      af_model.save_current_pdb(f\"output/all_pdb/n{n}.pdb\")\n",
        "      af_model._k += 1\n",
        "\n",
        "      line = f'>mpnn:{out[\"score\"][n]:.3f}_plddt:{out[\"plddt\"][n]:.3f}_ptm:{out[\"ptm\"][n]:.3f}_pae:{out[\"pae\"][n]:.3f}\\n{out[\"seq\"][n]}'\n",
        "      fasta.write(line+\"\\n\")\n",
        "      pbar.update(1)\n",
        "\n",
        "labels = [\"score\"] + af_terms + [\"seq\"]\n",
        "data = [[out[k][n] for k in labels] for n in range(num_seqs)]\n",
        "labels[0] = \"mpnn\"\n",
        "\n",
        "df = pd.DataFrame(data, columns=labels)\n",
        "df.to_csv('output/mpnn_results.csv')\n",
        "data_table.DataTable(df.round(3).sort_values(\"pae\"))"
      ],
      "metadata": {
        "cellView": "form",
        "id": "3H_B0AoYIiWH"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "id": "v3dPQeEQcAcT"
      },
      "outputs": [],
      "source": [
        "af_model.save_pdb(\"1.pdb\")\n",
        "af_model.plot_pdb()\n",
        "af_model.get_seqs()"
      ]
    }
  ],
  "metadata": {
    "accelerator": "GPU",
    "colab": {
      "provenance": [],
      "include_colab_link": true
    },
    "gpuClass": "standard",
    "kernelspec": {
      "display_name": "Python 3",
      "name": "python3"
    },
    "language_info": {
      "name": "python"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
}