Search results for "biotiini"

Uuden bakteeriperäisen avidiinin sukulaisproteiinin tuottaminen, puhdistus sekä sen ominaisuuksien määrittäminen

2007

Bifunktionaalisten reagenssien synteesi, ominaisuudet ja sovellukset

2006

Engineering of charge, biotin-binding and oligomerization of avidin : new tools for avidin-biotin technology

2002

Avidin is a tetrameric glycoprotein found in chicken egg white. Due to its remarkably high affinity for biotin, avidin has widely been used in biological and biotechnical applications in life sciences. Avidin is also a highly stable protein, maintaining its functional tetrameric structure at high temperatures, extremes of pH, and in the presence of strong denaturants. In the present study we wanted to find out whether different properties of avidin can be modified with protein engineering using rational design. We used the 3D-structure of avidin together with sequence information from various avidin-like proteins to plan these changes. Besides shedding more light on the protein chemical bas…

Strongavidiini - biotiinia sitova merisiilestä peräisin oleva avidiinin kaltainen proteiini

2009

Biotiinia eli vitamiinia H suurimmalla luonnossa tavatulla ei-kovalenttisella affiniteetilla sitovaa avidiinia ja sen bakteeriperäistä sukulaisproteiinia streptavidiini käytetään laajasti erilaisissa avidiini-biotiini teknologian sovellutuksissa. Alun perin avidiini löydettiin kananmunan valkuaisesta ja sen rakenne on myöhemmin selvitetty tarkasti. Avidiinilla ja streptavidiinilla on monia hyödyllisiä ominaisuuksia. Avidiinin ja streptavidiinin on havaittu biotiiniin sitouduttuaan olevan erittäin stabiileja proteiineja, jotka kestävät hyvin mm. proteolyyttisiä entsyymejä ja ne omaavat voimakkaan lämmönkestävyyden. Yksi avidiini koostuu neljästä samanlaisesta monomeeristä, joista jokainen py…

Avidin engineering : modification of function, oligomerization, stability and structure topology

2003

Avidiini on neljästä samanlaisesta alayksiköstä muodostunut tetrameerinen glykoproteiini, jota esiintyy luontaisesti, pieninä pitoisuuksina, kanan munanvalkuaisessa. Eräs avidiinin merkittävimmistä ominaisuuksista on sen kyky sitoa vitamiini biotiinia. Avidiinin ja biotiinin välinen vuorovaikutus on voimakkain tunnettu luonnossa esiintyvä ei-kovalenttinen sidos proteiinin ja sen ligandin välillä. Tätä ominaisuutta on hyödynnetty jo pitkään lukuisissa bio- ja lääketieteellisissä sovelluksissa, jotka yhdessä muodostavat niin kutsutun (strept)avidiini-biotiini -teknologian. Avidin is a basic and rather stable tetrameric glycoprotein found in chicken egg-white. It has an enormous affinity towar…

Chicken genome analysis reveals novel genes encoding biotin-binding proteins related to avidin family

2005

Background A chicken egg contains several biotin-binding proteins (BBPs), whose complete DNA and amino acid sequences are not known. In order to identify and characterise these genes and proteins we studied chicken cDNAs and genes available in the NCBI database and chicken genome database using the reported N-terminal amino acid sequences of chicken egg-yolk BBPs as search strings. Results Two separate hits showing significant homology for these N-terminal sequences were discovered. For one of these hits, the chromosomal location in the immediate proximity of the avidin gene family was found. Both of these hits encode proteins having high sequence similarity with avidin suggesting that chic…

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

2007

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 comp…