Formation of amyloid-like fibrils by ovalbumin and related proteins under conditions relevant to food processing.
Protein aggregation is important in food processing, and this work investigated the aggregation of food proteins as a source of amyloid fibrils for use in bionanotechnology. Both purified and crude mixtures of albumin proteins were denatured by heat, which caused aggregation to occur. Protein denaturation was measured by using circular dichroism spectrometry and by following thioflavin T fluorescence, which is widely used as a diagnostic test for amyloid formation. There was a good correlation between the increase in thioflavin T fluorescence and loss of helical structure as the temperature was increased. Formation of thioflavin T fluorescence was dependent on temperature, but less dependent on salt and protein concentration. X-ray fiber diffraction patterns of denatured bovine serum albumin suggested that the protein had a similar cross-beta structure to that of amyloid fibrils. These results are consistent with the aggregates seen during food processing, being amyloid-like in nature.
Pearce
F Grant
FG
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8020, New Zealand. grant.pearce@ canterbury.ac.nz
Mackintosh
Sarah H
SH
Gerrard
Juliet A
JA
D000682:Amyloid / Q000737:chemistry*; D052160:Benzothiazoles; D002942:Circular Dichroism; D005511:Food Handling; D010047:Ovalbumin / Q000737:chemistry*; D011489:Protein Denaturation; D011506:Proteins / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry; D014961:X-Ray Diffraction
D000682:Amyloid; D052160:Benzothiazoles; D011506:Proteins; D013844:Thiazoles; C009462:thioflavin T; D012710:Serum Albumin, Bovine; D010047:Ovalbumin