Tailocins are recurrent contaminants in ex vivo amyloid extraction
- 1Scripps Research
Abstract
Amyloid fibrils extracted from patient tissue are enriched by physicochemical fractionation methods and enzymatic tissue digestion with collagenase, resulting in a mixture of sedimented complexes. Reprocessing of an ex vivo lysozyme amyloid dataset revealed non-amyloid tubular assemblies, which we reconstructed to 3.5 angstrom. Sequence-agnostic model building with CryoAtom and fold search with FoldSeek identified a phage tail tube fold. Testing the crude Clostridium histolyticum collagenase used for tissue digestion, negative-stain TEM and LC-MS/MS showed proteins of an F-type tailocin, allowing us to assign the helical reconstruction to a major tail tube protein (TTP) of C. histolyticum. We also observed tailocin contamination in cardiac light-chain amyloid extracts, following the same collagenase treatment. Overall, we identify tailocins as recurrent reagent-borne contaminants in collagenase-treated ex vivo amyloid preparations and propose strategies to detect and avoid such artefacts in single-particle cryo-EM by optimizing the experimental design and data annotation towards a database of common contaminants.
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BibTeX
@misc{schaefer2026tailocins,
title = {{Tailocins are recurrent contaminants in ex vivo amyloid extraction}},
author = {J.-H. Schaefer and R. T. O'Neill and Z. Gao and D. A. Grotjahn and E. T. Powers and G. C. Lander and J. W. Kelly},
howpublished = {bioRxiv},
year = {2026},
month = jun,
doi = {10.64898/2026.06.17.733002},
url = {https://www.biorxiv.org/content/10.64898/2026.06.17.733002v2},
note = {CC BY},
}
RIS
TY - UNPB
TI - Tailocins are recurrent contaminants in ex vivo amyloid extraction
AU - J.-H. Schaefer
AU - R. T. O'Neill
AU - Z. Gao
AU - D. A. Grotjahn
AU - E. T. Powers
AU - G. C. Lander
AU - J. W. Kelly
PY - 2026
DA - 2026/06/17
PB - bioRxiv
DO - 10.64898/2026.06.17.733002
UR - https://www.biorxiv.org/content/10.64898/2026.06.17.733002v2
AB - Amyloid fibrils extracted from patient tissue are enriched by physicochemical fractionation methods and enzymatic tissue digestion with collagenase, resulting in a mixture of sedimented complexes. Reprocessing of an ex vivo lysozyme amyloid dataset revealed non-amyloid tubular assemblies, which we reconstructed to 3.5 angstrom. Sequence-agnostic model building with CryoAtom and fold search with FoldSeek identified a phage tail tube fold. Testing the crude Clostridium histolyticum collagenase used for tissue digestion, negative-stain TEM and LC-MS/MS showed proteins of an F-type tailocin, allowing us to assign the helical reconstruction to a major tail tube protein (TTP) of C. histolyticum. We also observed tailocin contamination in cardiac light-chain amyloid extracts, following the same collagenase treatment. Overall, we identify tailocins as recurrent reagent-borne contaminants in collagenase-treated ex vivo amyloid preparations and propose strategies to detect and avoid such artefacts in single-particle cryo-EM by optimizing the experimental design and data annotation towards a database of common contaminants.
ER -