Amyloid fibrils formation and amorphous aggregation in concanavalin A.
We here report an experimental study on the thermal aggregation process of concanavalin A, a protein belonging to the legume lectins family. The aggregation process and the involved conformational changes of the protein molecules were followed by means of fluorescence techniques, light scattering, circular dichroism, zeta potential measurements and atomic force microscopy. Our results show that the aggregation process of concanavalin A may evolve through two distinct pathways leading, respectively, to the formation of amyloids or amorphous aggregates. The relative extent of the two pathways is determined by pH, as amyloid aggregation is favored at high pH values ( approximately 9), while the formation of amorphous aggregates is favored at low pH ( approximately 5). At difference from amorphous aggregation, the formation of amyloid fibrils requires significant conformational changes on the protein, both at secondary and tertiary structural level. To our knowledge, this is the first observation of amyloid fibrils from concanavalin A.
Vetri
Valeria
V
Università di Palermo, Dipartimento di Scienze Fisiche ed Astronomiche, Via Archirafi 36, 90123 Palermo, Italy.
Canale
Claudio
C
Relini
Annalisa
A
Librizzi
Fabio
F
Militello
Valeria
V
Gliozzi
Alessandra
A
Leone
Maurizio
M
D000682:Amyloid / Q000096:biosynthesis / Q000737:chemistry*; D052160:Benzothiazoles; D003208:Concanavalin A / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D018625:Microscopy, Atomic Force; D020836:Protein Structure, Quaternary; D012542:Scattering, Radiation; D013844:Thiazoles
D000682:Amyloid; D052160:Benzothiazoles; D005456:Fluorescent Dyes; D013844:Thiazoles; D003208:Concanavalin A; C009462:thioflavin T