Abstract: Two circularly permuted avidin monomers arc designed. The circularly permuted monomers are fused and the resulting fusion peptides (dcAvd) form a pseudo-tetrameric dual-chain avidin, which is biologically active in biotin binding and shows similar structural characteristics as wild-type avidin. The dcAvd makes the development of dual-affinity avidins possible by allowing the adjustment of the ligand binding properties in the half of the binding sites differently than in the rest of the sites. The present invention provides further a single-chain avidin (scAvd) where two dcAvd-molecules are fused together via a linker to form a single polypeptide with four binding sites for biotin or other ligand.

Abstract: An isolated protein which is structurally and functionally similar to avidin but with improved properties, such as better affinity towards biotin conjugate, useful immunological properties or faster biotin dissociation rate, compared to avidin and streptavidin.

Abstract: Two circularly permuted avidin monomers are designed. The circularly permuted monomers (cpAvd5?4 and cpAvd6?5) are fused and the resulting fusion peptides (dcAvd) form a pseudo-tetrameric dual-chain avidin, which is biologically active in biotin binding and shows similar structural characteristics as wild-type avidin. The dcAvd makes the development of dual-affinity avidins possible by allowing the adjustment of the ligand binding properties in the half of the binding sites differently than in the rest of the sites. The present invention provides further a single-chain avidin (scAvd) where two dcAvd-molecules are fused together via a linker to form a single polypeptide with four binding sites for biotin.

Abstract: The present invention relates to new chimeric mutants of avidin protein with improved properties, e.g. thermostability, better stability against proteolysis, better charge properties (for example lower pl) compared to native avidin and avidin-related proteins, AVRs. The chimeric avidin mutants comprise mutants where a region or regions in avidin are substituted by a corresponding region or regions from an AVR protein.