Published data on the probable involvement of avidin and avidin-related protein-2 (AVR2) in sustaining sperm viability in sperm storage tubules in 38-wk-old turkeys, and the high affinity of avidin or its analogs to biotin suggest that supplementary biotin may increase oviductal avidin and AVR2 expression, thereby attenuating the adverse effect of aging on hen reproductive performance. Broiler ...

When the tissues of chicks maintained on a diet containing unheated egg white were found to be deficient in biotin in spite of the abundance of this vitamin in the diet (l), it was concluded that the injury caused by the egg white is not due to any direct toxin but rather is produced indirectly by the action of the egg white in making the biotin of the diet unavailable to the animal. To support...

PURPOSE Pretargeted radioimmunotherapy (PRIT) using streptavidin (SAv)-biotin technology can deliver higher therapeutic doses of radioactivity to tumors than conventional RIT. However, "endogenous" biotin can interfere with the effectiveness of this approach by blocking binding of radiolabeled biotin to SAv. We engineered a series of SAv FPs that downmodulate the affinity of SAv for biotin, whi...

Although the physical, chemical and kinetic properties as well as the biological function of pyruvate carboxylase have been studied in detail (for review see Utter et al., 1975), no reports have been published so far on the primary structure of this enzyme. This may be due in part to the large size of the molecule since the vertebrate enzyme appears to be a tetramer consisting of four apparentl...

Biotin (vitamin B7), an essential micronutrient for normal cellular functions, is obtained from both dietary sources as well as gut microbiota. Absorption of biotin in both the small and large intestine is via a carrier-mediated process that involves the sodium-dependent multivitamin transporter (SMVT). Although different physiological and molecular aspects of intestinal biotin uptake have been...

The demonstration of the marked biological activity of oxybiotin (l-4), the oxygen analogue of biotin, has focused attention upon the mode of action of this compound. It became of particular interest to determine whether oxybiotin possesses intrinsic activity or whether its biological potency is due to its conversion into biotin. The evidence in the literature is conflicting on this point. Hofm...

Biotin deficiency is known to affect immune function in both humans and experimental animals. In this study, we determined the effect of biotin deficiency on 4-wk-old Balb/cAnN mice during 20 wk of experimentation. The growth rate of mice slowed significantly during the first 6 wk of consumption of a diet designed to induce biotin deficiency; thereafter, from weeks 7 to 20 there was progressive...

To determine the effects of excess biotin administration on growth and water-soluble vitamin metabolism, weaning rats were fed on a 20% casein diet containing 0.00002% biotin, or same diet with 0.04, 0.08, 0.10, 0.20, 0.50, 0.80 or 1.0% added biotin for 28 days. More than 0.08% biotin administration decreased the food intake and body weight gain compared with the levels in control rats. An accu...

Peripheral blood mononuclear cells (PBMC) accumulate biotin by a Na-dependent energy-requiring transporter. This transporter might be the so-called Na-dependent multivitamin transporter, but kinetic observations suggest the existence of a second, more specific, biotin transporter. PBMC respond to proliferation by increased uptake of biotin; the increase is probably mediated by an increased numb...