Structure and characterization of a novel chicken biotin-binding protein A (BBP-A)

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Hytonen VP, Maatta JAE, Niskanen EA, Huuskonen J, Helttunen KJ, Halling KK, Nordlund HR, Rissanen K, Johnson MS, Salminen TA, Kulomaa MS, Laitinen OH, Airenne TT
Förläggare: BIOMED CENTRAL LTD
Publiceringsår: 2007
Tidskrift: BMC STRUCTURAL BIOLOGY
Tidskriftsakronym: BMC STRUCT BIOL
Volym: 7
Antal sidor: 20
ISSN: 1471-2237


Abstrakt

Background: The chicken genome contains a BBP-A gene showing similar characteristics to avidin family genes. In a previous study we reported that the BBP-A gene may encode a biotin-binding protein due to the high sequence similarity with chicken avidin, especially at regions encoding residues known to be located at the ligand-binding site of avidin.Results: Here, we expand the repertoire of known macromolecular biotin binders by reporting a novel biotin-binding protein A (BBP-A) from chicken. The BBP-A recombinant protein was expressed using two different expression systems and purified with affinity chromatography, biochemically characterized and two X-ray structures were solved - in complex with D-biotin (BTN) and in complex with D-biotin D-sulfoxide (BSO). The BBP-A protein binds free biotin with high, "streptavidin-like" affinity (K-d similar to 10(-13) M), which is about 50 times lower than that of chicken avidin. Surprisingly, the affinity of BBP-A for BSO is even higher than the affinity for BTN. Furthermore, the solved structures of the BBP-A - BTN and BBP-A - BSO complexes, which share the fold with the members of the avidin and lipocalin protein families, are extremely similar to each other.Conclusion: BBP-A is an avidin-like protein having a beta-barrel fold and high affinity towards BTN. However, BBP-A differs from the other known members of the avidin protein family in thermal stability and immunological properties. BBP-A also has a unique ligand-binding property, the ability to bind BTN and BSO at comparable affinities. BBP-A may have use as a novel material in, e. g. modern bio(nano) technological applications.

Senast uppdaterad 2019-12-11 vid 05:21

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