Spectroscopic Identification of Peptide Chemistry in the Caulobacter crescentus Holdfast.
Biochemistry
; 59(37): 3508-3516, 2020 09 22.
Article
em En
| MEDLINE
| ID: mdl-32844640
ABSTRACT
The bacterium Caulobacter crescentus is known to attach irreversibly to underwater surfaces by utilizing an adhesive structure called the holdfast, which exhibits the greatest known adhesive strength of any organism. The very small size of the holdfast (â¼400 nm wide and â¼40 nm high) has made direct chemical analysis difficult, and its structure remains poorly understood. In this study, we employ spectroscopic techniques, including attenuated total reflection infrared spectroscopy (ATR-IR) and X-ray photoelectron spectroscopy, to probe holdfast chemistry. The data indicate the presence of a peptide signal within the holdfast polymer. By comparing the ATR-IR spectrum of the holdfast to peptidoglycan spectra from other bacterial species, we demonstrate the similarity of the holdfast chemistry to that of peptidoglycan, suggesting peptide cross-linking may play a role in holdfast architecture. To probe the molecular groups at the interface, surface-sensitive sum frequency generation spectroscopy was used to show that aromatic and hydroxyl groups related to this protein content at the adhesive interface could be playing a crucial role in adhesion. On the basis of these results, we propose a model of the holdfast architecture with similarities to the peptide cross-linking observed in the peptidoglycan polymer of the bacterial cell wall. These results not only provide information about the development of adhesives that could be based on holdfast chemical architecture but also reveal a potentially yet unexplored biosynthetic pathway in holdfast synthesis that has not yet been revealed by genetic approaches, thereby opening up a potentially new avenue of research in holdfast synthesis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Proteínas de Bactérias
/
Aderência Bacteriana
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Peptidoglicano
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Proteínas de Transporte
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Caulobacter crescentus
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Adesinas Bacterianas
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
Biochemistry
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos