Infiltration of chitin by protein coacervates defines the squid beak mechanical gradient.
Nat Chem Biol
; 11(7): 488-95, 2015 Jul.
Article
em En
| MEDLINE
| ID: mdl-26053298
ABSTRACT
The beak of the jumbo squid Dosidicus gigas is a fascinating example of how seamlessly nature builds with mechanically mismatched materials. A 200-fold stiffness gradient begins in the hydrated chitin of the soft beak base and gradually increases to maximum stiffness in the dehydrated distal rostrum. Here, we combined RNA-Seq and proteomics to show that the beak contains two protein families. One family consists of chitin-binding proteins (DgCBPs) that physically join chitin chains, whereas the other family comprises highly modular histidine-rich proteins (DgHBPs). We propose that DgHBPs play multiple key roles during beak bioprocessing, first by forming concentrated coacervate solutions that diffuse into the DgCBP-chitin scaffold, and second by inducing crosslinking via an abundant GHG sequence motif. These processes generate spatially controlled desolvation, resulting in the impressive biomechanical gradient. Our findings provide novel molecular-scale strategies for designing functional gradient materials.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Decapodiformes
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Bico
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Água
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Proteínas
/
Quitina
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article