AntiBERTy

Official repository for AntiBERTy, an antibody-specific transformer language model pre-trained on 558M natural antibody sequences, as described in Deciphering antibody affinity maturation with language models and weakly supervised learning.

Setup

To use AntiBERTy, install via pip:

pip install antiberty

Alternatively, you can clone this repository and install the package locally:

$ git clone git@github.com:jeffreyruffolo/AntiBERTy.git 
$ pip install AntiBERTy

Usage

Embeddings

To use AntiBERTy to generate sequence embeddings, use the embed function. The output is a list of embedding tensors, where each tensor is the embedding for the corresponding sequence. Each embedding has dimension [(Length + 2) x 512].

from antiberty import AntiBERTyRunner

antiberty = AntiBERTyRunner()

sequences = [
    "EVQLVQSGPEVKKPGTSVKVSCKASGFTFMSSAVQWVRQARGQRLEWIGWIVIGSGNTNYAQKFQERVTITRDMSTSTAYMELSSLRSEDTAVYYCAAPYCSSISCNDGFDIWGQGTMVTVS",
    "DVVMTQTPFSLPVSLGDQASISCRSSQSLVHSNGNTYLHWYLQKPGQSPKLLIYKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFCSQSTHVPYTFGGGTKLEIK",
]
embeddings = antiberty.embed(sequences)

To access the attention matrices, pass the return_attention flag to the embed function. The output is a list of attention matrices, where each matrix is the attention matrix for the corresponding sequence. Each attention matrix has dimension [Layer x Heads x (Length + 2) x (Length + 2)].

from antiberty import AntiBERTyRunner

antiberty = AntiBERTyRunner()

sequences = [
    "EVQLVQSGPEVKKPGTSVKVSCKASGFTFMSSAVQWVRQARGQRLEWIGWIVIGSGNTNYAQKFQERVTITRDMSTSTAYMELSSLRSEDTAVYYCAAPYCSSISCNDGFDIWGQGTMVTVS",
    "DVVMTQTPFSLPVSLGDQASISCRSSQSLVHSNGNTYLHWYLQKPGQSPKLLIYKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFCSQSTHVPYTFGGGTKLEIK",
]
embeddings, attentions = antiberty.embed(sequences, return_attention=True)

The embed function can also be used with masked sequences. Masked residues should be indicated with underscores.

Classification

To use AntiBERTy to predict the species and chain type of sequences, use the classify function. The output is two lists of classifications for each sequences.

from antiberty import AntiBERTyRunner

antiberty = AntiBERTyRunner()

sequences = [
    "EVQLVQSGPEVKKPGTSVKVSCKASGFTFMSSAVQWVRQARGQRLEWIGWIVIGSGNTNYAQKFQERVTITRDMSTSTAYMELSSLRSEDTAVYYCAAPYCSSISCNDGFDIWGQGTMVTVS",
    "DVVMTQTPFSLPVSLGDQASISCRSSQSLVHSNGNTYLHWYLQKPGQSPKLLIYKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFCSQSTHVPYTFGGGTKLEIK",
]
species_preds, chain_preds = antiberty.classify(sequences)

The classify function can also be used with masked sequences. Masked residues should be indicated with underscores.

Mask prediction

To use AntiBERTy to predict the identity of masked residues, use the fill_masks function. Masked residues should be indicated with underscores. The output is a list of filled sequences, corresponding to the input masked sequences.

from antiberty import AntiBERTyRunner

antiberty = AntiBERTyRunner()

sequences = [
    "____VQSGPEVKKPGTSVKVSCKASGFTFMSSAVQWVRQARGQRLEWIGWIVIGSGN_NYAQKFQERVTITRDM__STAYMELSSLRSEDTAVYYCAAPYCSSISCNDGFD____GTMVTVS",
    "DVVMTQTPFSLPV__GDQASISCRSSQSLVHSNGNTY_HWYLQKPGQSPKLLIYKVSNRFSGVPDRFSG_GSGTDFTLKISRVEAEDLGVYFCSQSTHVPYTFGG__KLEIK",
]
filled_sequences = antiberty.fill_masks(sequences)

Pseudo log-likelihood

To use AntiBERTy to calculate the pseudo log-likelihood of a sequence, use the pseudo_log_likelihood function. The pseudo log-likelihood of a sequence is calculated as the average of per-residue masked log-likelihoods. The output is a list of pseudo log-likelihoods, corresponding to the input sequences.

from antiberty import AntiBERTyRunner

antiberty = AntiBERTyRunner()

sequences = [
    "EVQLVQSGPEVKKPGTSVKVSCKASGFTFMSSAVQWVRQARGQRLEWIGWIVIGSGNTNYAQKFQERVTITRDMSTSTAYMELSSLRSEDTAVYYCAAPYCSSISCNDGFDIWGQGTMVTVS",
    "DVVMTQSSTPFSLPVSLGDQASISCRSSQSLVHSNGNTYLHWYLQKPGQSPKLLIYKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFCSQSTHVPYTFGGGTKLEIK",
]

pll = antiberty.pseudo_log_likelihood(sequences, batch_size=16)

Citing this work

@article{ruffolo2021deciphering,
    title = {Deciphering antibody affinity maturation with language models and weakly supervised learning},
    author = {Ruffolo, Jeffrey A and Gray, Jeffrey J and Sulam, Jeremias},
    journal = {arXiv preprint arXiv:2112.07782},
    year= {2021}
}