Characterization of the adhesive plaque of the barnacle Balanus amphitrite: amyloid-like nanofibrils are a major component.
The nanoscale morphology and protein secondary structure of barnacle adhesive plaques were characterized using atomic force microscopy (AFM), far-UV circular dichroism (CD) spectroscopy, transmission Fourier transform infrared (FTIR) spectroscopy, and Thioflavin T (ThT) staining. Both primary cement (original cement laid down by the barnacle) and secondary cement (cement used for reattachment) from the barnacle Balanus amphitrite (= Amphibalanus amphitrite) were analyzed. Results showed that both cements consisted largely of nanofibrillar matrices having similar composition. Of particular significance, the combined results indicate that the nanofibrillar structures are consistent with amyloid, with globular protein components also identified in the cement. Potential properties, functions, and formation mechanisms of the amyloid-like nanofibrils within the adhesive interface are discussed. Our results highlight an emerging trend in structural biology showing that amyloid, historically associated with disease, also has functional roles.
Barlow
Daniel E
DE
U.S. Naval Research Laboratory, Code 6176, Washington, District of Columbia 20375-5342, USA. daniel.barlow@nrl.navy.mil
Dickinson
Gary H
GH
Orihuela
Beatriz
B
Kulp
John L
JL
Rittschof
Daniel
D
Wahl
Kathryn J
KJ
D000269:Adhesives / Q000737:chemistry / Q000378:metabolism; D000682:Amyloid / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D002942:Circular Dichroism; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared; D001468:Thoracica / Q000737:chemistry*
D000269:Adhesives; D000682:Amyloid