Amyloid fibril formation in vitro from halophilic metal binding protein: its high solubility and reversibility minimized formation of amorphous protein aggregations.

ABSTRACT: Halophilic proteins are characterized by high net negative charges and relatively small fraction of hydrophobic amino acids, rendering them aggregation resistant. These properties are also shared by histidine-rich metal binding protein (HP) from moderate halophile, Chromohalobacter salexigens, used in this study. Here, we examined how halophilic proteins form amyloid fibrils in vitro. His-tagged HP, incubated at pH 2.0 and 58°C, readily formed amyloid fibrils, as observed by thioflavin fluorescence, CD spectra, and transmission or atomic force microscopies. Under these low-pH harsh conditions, however, His-HP was promptly hydrolyzed to smaller peptides most likely responsible for rapid formation of amyloid fibril. Three major acid-hydrolyzed peptides were isolated from fibrils and turned o

SUBMITTER: Tokunaga Y 

PROVIDER: S-EPMC3831673 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature