Zebavidin - An Avidin-Like Protein from Zebrafish

Abstract

The avidin protein family members are well known for their high affinity towards D-biotin and high structural stability. These properties make avidins valuable tools for a wide range of biotechnology applications. We have identified a new member of the avidin family in the zebrafish (Danio rerio) genome, hereafter called zebavidin. The protein is highly expressed in the gonads of both male and female zebrafish and in the gills of male fish, but our data suggest that zebavidin is not crucial for the developing embryo. Biophysical and structural characterisation of zebavidin revealed distinct properties not found in any previously characterised avidins. Gel filtration chromatography and native mass spectrometry suggest that the protein forms dimers in the absence of biotin at low ionic strength, but assembles into tetramers upon binding biotin. Ligand binding was analysed using radioactive and fluorescently labelled biotin and isothermal titration calorimetry. Moreover, the crystal structure of zebavidin in complex with biotin was solved at 2.4 Å resolution and unveiled unique ligand binding and subunit interface architectures; the atomic-level details support our physicochemical observations.

The principles and applications of avidin-based nanoparticles in drug delivery and diagnosis

“…Other recombinant or naturally occurring avidin include Tamavidin 2 ( Pleurotus cornucopiae )[40], Shwanavidin ( Shewanella denitrificans )[41], Switchavidin (chicken avidin mutant)[42], Zebavidin (Zebrafish)[43]. …”

Hoefavidin: A dimeric bacterial avidin with a C-terminal binding tail

“…The peptides mainly interact with Trp 81 of the biotin-binding site, with the Phe side chain of hoef-pep(L9F) occupying slightly higher contact surface area than the Leu residue of the wild-type peptide. Nordlund et al, 2005;Taskinen et al, 2013). The exact role they play in the host organism is still obscure.…”

Crystal structure of afifavidin reveals common features of molecular assemblage in the bacterial dimeric avidins

“…Technologies based on the avidin–biotin system have been developed and utilized for decades by exploiting its extremely high affinity (Kd ~ 10 −15 m ) . There are many proteins belonging to the avidin family, originating from various organisms, ranging from bacteria to fungi, birds, reptiles and fish . Most of these proteins, notably hen's egg‐white avidin and bacterial streptavidin, consist of a homo‐tetrameric quaternary structure, wherein each monomer comprises an 8‐stranded β‐barrel that bears a biotin‐binding site .…”