Disease relevance of Btd

• Hearing loss affects children with biotinidase deficiency, an inherited metabolic disorder in the recycling of biotin [1].
• The highest specific activities (Vs) for biotinidase were found in Lactobacillus casei (Shirota) and rat kidney [2].

High impact information on Btd

• A second set of biotin derivatives, 3a, 4a, and 5a, were synthesized which had structures that contain a biotin moiety, a biotinidase-blocking moiety, and an anionic nido-carborane moiety for radiohalogenation [3].
• As part of our continuing investigation of pretargeting, a new water-solubilized biotinidase-stabilized biotinylation reagent was prepared [4].
• Biotinidase reveals the morphogenetic sequence in cochlea and cochlear nucleus of mice [1].
• DL-ethionine increases the activity of liver biotinidase, an enzyme which hydrolyzes biotinylesters and biotinylpeptides [5].
• Enhancement of biotinidase activity in mouse serum by inhibitors of methylation [5].

Biological context of Btd

• In the present work we show that both isomers of DL-ethionine are equally good enhancers of the liver biotinidase, while, 3-ethylthiopropionate, the toxic metabolite of DL-ethionine, has no effect on the biotinidase activity of either liver or serum [5].
• It was concluded that excessive amounts of biotin affected the specific activity of biotinidase in pregnant mice, but did not disturb normal reproductive functions and embryonic development [6].

Associations of Btd with chemical compounds

• These findings suggest that biotinidase and possibly biotin plays an important role in hearing [7].
• Because SAH does not ethylate biomolecules, these changes in biotinidase activity, which can not be prevented by adenine, biotin or lecithin are most probably related to the inhibition of methylation [5].
• It was found that these inhibitors (EHNA and Ara-A, 2-deoxycoformycin and adenosine) increase the activity of serum biotinidase as was the case with ethionine [5].

Analytical, diagnostic and therapeutic context of Btd

• To better characterize the nature of the hearing loss in this disorder, location of the expression and presence of biotinidase within the brain was examined using Northern blot analysis, in vitro hybridization of a cDNA panel, and immunohistochemical staining [7].
• Enzyme kinetic parameters, such as K(m), V(max) (or V), k(cat)/K(m), and K(i) (by biotin or lipoic acid) for biotinidase and lipoamidase were determined in Lewis (LEW) rat and Lactobacillus casei (Shirota) using fluorimetric high-performance liquid chromatography (HPLC) [2].

References