The de novo protein with grafted biological function: transferring of interferon blast-transforming activity to albebetin

Abstract

The de novo protein albebetin has been designed recently to form a predetermined tertiary fold that has not yet been observed in natural proteins. An eight amino acid fragment (131-138) of human interferon alpha(2) carrying the blast-transforming activity of the protein was attached to the N-terminus of albebetin next to its initiatory methionine residue. The gene of chimeric protein was expressed in a wheat germ cell-free translation system and synthesized protein was tested for its compactness and stability. Its ability for receptor binding was also studied. We have shown that albebetin with attached octapeptide is practically as compact as natural proteins of corresponding molecular weight and possesses high stability toward the urea-induced unfolding. It binds murine thymocyte receptor at a high affinity and activates the thymocyte blast transformation efficiently at a concentration of 10(-11) M.

Cytotoxicity of albebetin oligomers depends on cross‐β‐sheet formation

“…Fibrillation process of albebetin, shown to be in a molten globule conformation under neutral pH [17][18][19][20], involves the formation of multiple amyloid species, among which at least two types of oligomers can be identified. The first ones are 10-15-mers assembled during the lag phase of incubation.…”

“…Albebetin was expressed in Escherichia coli and purified as described previously [18]. Its concentration was determined by using Bradford assay.…”

“…Albebetin was engineered as a protein with pre-determined 3D structure [17] and it was used as an inert carrier matrix for drug delivery [18][19][20]. It is a 73 amino acid residue protein composed of two sets of abb motives forming four stranded b-sheet covered by two a-helices and characterized by a mobile molten globule type conformation at neutral pH.…”

Structural Similarity between Defense Peptide from Wheat and Scorpion Neurotoxin Permits Rational Functional Design

“…It is interesting that after the first draft of the primary design of albebetin was proposed a similar fold was found in some natural proteins (14,15). It was further shown that this artificial protein can be used as a scaffold for engineering desired biological functions (16).…”

A False Paradise - Mixed Blessings in the Protein Universe: The Amyloid as a New Challenge in Drug Development

“…This was demonstrated on the de novo protein albebetin, which was designed as a molten globule carrier for biopharmaceutical applications. It is highly soluble and immunologically inert, but unfortunately appeared to be extremely amyloidogenic under physiological conditions [42,50,[77][78][79][80]. A large number of natively unfolded proteins were found to be amyloidogenic, including α-synuclein [81], mammalian prothymosin α [82], 71 amino acid fragment of gelsolin mutant [83] and others.…”