The chicken avidin gene family consists of avidin and seven separate avidin-related genes (AVRs) 1-7. Avidin protein is a widely used biochemical tool, whereas the other family members have only recently been produced as recombinant proteins and characterized. In our previous study, AVR4 was found to be the most stable biotin binding protein thus far characterized (T(m) = 106.4 degrees C). In t...

The electroanalytical determination of avidin in solution, in a carbon paste, and in a transgenic maize extract was performed in acidic medium at a carbon paste electrode (CPE). The oxidative voltammetric signal resulting from the presence of tyrosine and tryptophan in avidin was observed using square-wave voltammetry. The process could be used to determine avidin concentrations up to 3 fM (100...

Using atomic force microscopy (AFM) we performed dynamic force measurements of the adhesive forces in two model systems: avidin-biotin and streptavidin-biotin. In our experiments we used glutaraldehyde for immobilization of (strept)avidin on the tip and biotin on the sample surface. Such interface layers are more rigid than those usually reported in the literature for AFM studies, when (strept)...

Avidin and avidin-like proteins are widely used in numerous techniques since the avidin-biotin interaction is known to be very robust and reliable. Within this study, we investigated this bond at the molecular level under harsh conditions ranging from very low to very high pH values. We compared avidin with streptavidin and a recently developed avidin-based mutant, chimeric avidin. To gain insi...

RNA was extracted from oviduct, shell gland, and liver of chicks treated with diethylstilbestrol and a combination of diethylstilbestrol and progesterone. Preparations containing 500 or 2500 mug of RNA were put in the oviductal lumen of diethylstilbestrol-treated chicks for 24 hr, and the avidin content of the oviduct was determined by measurement of [(14)C]biotin binding. The results of the pr...

Avidin-biotin interaction is one of the strongest non-covalent interactions in the nature. Avidin and its analogues have therefore been extensively utilized as probes and affinity matrices for a wide variety of applications in biochemical assays, diagnosis, affinity purification, and drug delivery. Recently, there has been a growing interest in exploring this non-covalent interaction in nanosca...

Biotinylation of erythrocytes (E) followed by avidin cross-linking at specific sites has been suggested as a novel means of drug delivery. Upon avidin cross-linking, biotinylated E become complement-activating and highly susceptible to complement lysis, thus bringing about release of entrapped drug. We set out to examine the mechanisms of this biotin-avidin-induced lytic susceptibility, focusin...

scAvd (single-chain avidin, where two dcAvd are joined in a single polypeptide chain), having four biotin-binding domains, was constructed by fusion of topologically modified avidin units. scAvd showed similar biotin binding and thermal stability properties as chicken avidin. The DNA construct encoding scAvd contains four circularly permuted avidin domains, plus short linkers connecting the fou...

The Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), is the most destructive insect pest of potato, Solanum tuberosum (L.), in North America. Avidin sequesters available biotin, thereby causing abnormal growth and development of insects. We expressed avidin in two potato lines: MSE149-5Y, a susceptible potato line, and ND5873-15, a line with S. chacoense-deri...