/esm-protein-language-model

name: esm-protein-language-model
description: "Protein language models (ESM3, ESM C) for sequence generation, structure prediction, inverse folding, and embeddings. Design novel proteins, extract ML features, or fold sequences. Local GPU or EvolutionaryScale Forge API. Use AlphaFold for traditional folding; RDKit for small molecules."
license: MIT

ESM — Protein Language Models

Overview

ESM (Evolutionary Scale Modeling) provides pretrained protein language models for generative protein design and representation learning. ESM3 is a multimodal generative model conditioned on sequence, structure, and function simultaneously. ESM C is an efficient embedding model optimized for extracting protein representations for downstream ML tasks.

When to Use

• Generating novel protein sequences conditioned on desired structure or function
• Extracting fixed-length embeddings from protein sequences for classification, clustering, or regression
• Predicting 3D structure from amino acid sequence
• Inverse folding: designing sequences that fold into a target structure
• Annotating proteins with functional keywords (GO terms, EC numbers)
• Comparing protein similarity via embedding distance instead of sequence alignment
• Chain-of-thought protein design: iterative refinement of sequence/structure/function
• For **traditional physics-based structure prediction**, use AlphaFold instead
• For **sequence alignment and homology search**, use BLAST/HMMER via BioPython instead

Prerequisites

• **Python packages**: `esm` (EvolutionaryScale package)
• **Hardware**: GPU recommended for local inference (ESM3: 8GB+ VRAM; ESM C: 4GB+ VRAM). CPU works for small batches
• **Cloud alternative**: EvolutionaryScale Forge API (requires API token from forge.evolutionaryscale.ai)
• **Model weights**: Downloaded automatically on first use (~1-4 GB depending on model)

pip install esm
# For Forge cloud API
pip install esm[forge]

Quick Start

from esm.models.esmc import ESMC
from esm.sdk.api import ESMProtein

# Load ESM C model for embeddings
model = ESMC.from_pretrained("esmc_600m")

# Create protein from sequence
protein = ESMProtein(sequence="MKTAYIAKQRQISFVKSHFSRQLEERLGLIEVQAPILSRVGDGTQDNLSGAEKAVQVKVKALPDAQFEVVHSLAKWKRQQIAATGFHIIPGDKPDNRAGGYDN")

# Get per-residue embeddings
output = model(protein)
embeddings = output.embeddings  # shape: (1, seq_len, embedding_dim)
print(f"Embedding shape: {embeddings.shape}")
# Embedding shape: (1, 101, 1152)

Core API

1. Protein Sequence Generation (ESM3)

Generate novel protein sequences conditioned on structure, function, or partial sequence.

from esm.models.esm3 import ESM3
from esm.sdk.api import ESM3InferenceClient, ESMProtein, GenerationConfig

# Load ESM3 locally
model = ESM3.from_pretrained("esm3_sm_open_v1")

# Generate from partial sequence (fill in masked positions)
prompt = ESMProtein(sequence="MKTAYIAK____ISFVK____RQLEERLG")  # ____ = positions to generate
config = GenerationConfig(track="sequence", num_steps=10, temperature=0.7)
generated = model.generate(prompt, config)
print(f"Generated sequence: {generated.sequence[:50]}...")

# Conditional generation: design sequence for a target structure
from esm.sdk.api import ESMProtein, GenerationConfig
from esm.utils.structure.protein_chain import ProteinChain

# Load target structure from PDB
chain = ProteinChain.from_pdb("target.pdb")
prompt = ESMProtein.from_protein_chain(chain)
prompt.sequence = None  # Clear sequence, keep structure

config = GenerationConfig(track="sequence", num_steps=16, temperature=0.5)
designed = model.generate(prompt, config)
print(f"Designed sequence ({len(designed.sequence)} residues): {designed.sequence[:50]}...")

2. Protein Embeddings (ESM C)

Extract fixed-length representations for downstream ML tasks.

from esm.models.esmc import ESMC
from esm.sdk.api import ESMProtein
import torch

model = ESMC.from_pretrained("esmc_600m")  # or "esmc_300m" for lighter model

sequences = [
    "MKTAYIAKQRQISFVKSHFSRQLEERLGLIEVQAPILSRVGDGTQDNLSGAEKAVQVKVKALPDAQFEVVHSLAKWKRQQIAATGFHIIPGDKPDNRAGGYDN",
    "MKWVTFISLLFLFSSAYSRGVFRRDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHVKLVNEVTEFAKTCVADESAENCDKS",
]

embeddings = []
for seq in sequences:
    protein = ESMProtein(sequence=seq)
    output = model(protein)
    # Mean-pool per-residue embeddings to get fixed-length vector
    mean_emb = output.embeddings.mean(dim=1)  # shape: (1, embedding_dim)
    embeddings.append(mean_emb)

emb_matrix = torch.cat(embeddings, dim=0)
print(f"Embedding matrix: {emb_matrix.shape}")  # (2, 1152)

# Compute pairwise similarity
similarity = torch.cosine_similarity(emb_matrix[0:1], emb_matrix[1:2])
print(f"Cosine similarity: {similarity.item():.4f}")

3. Structure Prediction

Predict 3D coordinates from amino acid sequence.

from esm.models.esm3 import ESM3
from esm.sdk.api import ESMProtein, GenerationConfig

model = ESM3.from_pretrained("esm3_sm_open_v1")

protein = ESMProtein(sequence="MKTAYIAKQRQISFVKSHFSRQLEERLGLIEVQAPILSRVGDGTQDNLSGAEKAVQVKVKALPDAQFEVVHSLAKWKRQQIAATGFHIIPGDKPDNRAGGYDN")

# Generate structure from sequence
config = GenerationConfig(track="structure", num_steps=16)
result = model.generate(protein, config)

# Save predicted structure
result.to_pdb("predicted.pdb")
print(f"Saved structure: {len(result.sequence)} residues → predicted.pdb")

4. Inverse Folding

Design amino acid sequences that fold into a target 3D structure.

from esm.models.esm3 import ESM3
from esm.sdk.api import ESMProtein, GenerationConfig
from esm.utils.structure.protein_chain import ProteinChain

model = ESM3.from_pretrained("esm3_sm_open_v1")

# Load target structure
chain = ProteinChain.from_pdb("target_structure.pdb")
prompt = ESMProtein.from_protein_chain(chain)

# Clear sequence but keep structure coordinates
prompt.sequence = None

# Generate multiple designs
designs = []
for i in range(5):
    config = Gene