Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.5.1.12 (biotinidase)
392 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The possible excretion of biocytin or biotinyl-peptides was investigated in urines of children with congenital biotinidase deficiency. Treatment of urine samples of affected children with normal plasma (as source of biotinidase) liberated additional free biotin (L. plantarum assay), indicating the presence of biotinyl-compounds. Using thin-layer chromatography the occurrence of biocytin was demonstrated in all urine samples of the affected children. In contrast, no biocytin could be detected in urines of healthy subjects.
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PMID:Detection of biocytin in urine of children with congenital biotinidase deficiency. 643 10

The previously reported method for the estimation of biotinidase (EC 3.5.1.12) is an endpoint colorimetric assay based on the hydrolysis of biotinyl-4-aminobenzoate, followed by diazotization, and is not suitable for our studies of biotinidase. A fluorimetric rate assay of biotinidase which uses a newly synthesized derivative biotinyl-6-aminoquinoline is described here.
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PMID:A sensitive fluorimetric rate assay for biotinidase using a new derivative of biotin, biotinyl-6-aminoquinoline. 654 38

A new, sensitive radioassay for the determination of biotinidase activity was developed which measures the release of [14C-carboxyl]-p-aminobenzoate from N-biotinyl-[14C-carboxyl]-p-aminobenzoate. Biotinidase activity in serum from normal individuals is comparable to that determined by the colorimetric assay, but the radioassay is approximately 100 times more sensitive. Biotinidase deficiency was confirmed in the serum of patients who were previously shown to have reduced activities by the colorimetric assay. Although biotinidase activity was not detectable in extracts of normal peripheral blood leukocytes and fibroblasts using the colorimetric assay, activities could be measured by the radioassay. Using this method we demonstrated deficient biotinidase activity in extracts of leukocytes and fibroblasts from affected patients.
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PMID:A sensitive radioassay for biotinidase activity: deficient activity in tissues of serum biotinidase-deficient individuals. 666 19

We describe a method for neonatal screening for biotinidase (EC 3.5.1.12) deficiency. Biotinidase activity is assessed colorimetrically from dried samples of whole blood spotted on the same filter papers as used in the neonatal screening for phenylketonuria. After the reaction, samples from normal infants are characteristically purple, whereas those from affected individuals are straw-colored. To confirm the deficiency, the enzyme is quantitatively assayed in additional blood spots or serum. A pilot study has been initiated with samples obtained by the Commonwealth of Virginia for phenylketonuria testing.
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PMID:A screening method for biotinidase deficiency in newborns. 669 Jan 18

Biotinidase deficiency is the usual biochemical defect in biotin-responsive late-onset multiple carboxylase deficiency. We reviewed the clinical features of six patients with the enzyme deficiency and compared them with features described in the literature in children with late-onset MCD. In all of the reported probands, MCD was diagnosed because they had metabolic ketoacidosis and organic aciduria in addition to various neurologic and cutaneous symptoms, such as seizures, ataxia, skin rash, and alopecia. Although in several of our patients biotinidase deficiency was also diagnosed because they manifested a similar spectrum of findings, others never had ketoacidosis or organic aciduria. Thus the initial features of biotinidase deficiency usually include neurologic or cutaneous symptoms, whereas organic aciduria and MCD are delayed, secondary manifestations of the disease. These findings suggest that biotinidase deficiency should be considered in any infant or child with any of these neurologic or cutaneous findings, with or without ketoacidosis or organic aciduria. If the diagnosis cannot be excluded, such individuals should be given a therapeutic trial of pharmacologic doses of biotin.
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PMID:Phenotypic variation in biotinidase deficiency. 687 14

Late-onset multiple carboxylase deficiency is characterized clinically by skin rash, alopecia, seizures and ataxia and occasionally by candidiasis and developmental delay. Biochemically, these individuals exhibit findings consistent with a combined deficiency of the biotin-dependent carboxylases. We have found that the activity of the enzyme biotinidase is also deficient in the sera of five affected children (0 to 3% of mean control activity, 5.80 +/- 0.89 nmol X min-1 X ml-1 serum), and believe that it represents the primary biochemical defect in this disease. Biotinidase catalyzes the removal of biotin from the epsilon-amino group of lysine, through which biotin is covalently bound to the four known human carboxylases, thereby regenerating biotin for reutilization. The deficient activity in our patients was not due to an inhibitor, particularly biotin. It is also not a consequence of feedback control in affected individuals under treatment with pharmacologic doses of biotin. The biotinidase activities of the parents of those children who were available for study were intermediate between deficient and normal values (46% to 65% of mean normal activity). Children lacking biotinidase activity are unable to recycle biotin, and are thus entirely dependent upon exogenous biotin to prevent deficiency. Our findings indicate that the primary biochemical defect in late-onset multiple carboxylase deficiency is in biotinidase activity which is inherited as an autosomal recessive trait.
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PMID:Biotinidase deficiency: the enzymatic defect in late-onset multiple carboxylase deficiency. 688 21

Biotinidase (EC 3.5.1.12) catalyzes the hydrolysis of biocytin, the product of biotin-dependent carboxylase degradation, to biotin and lysine. Biotinidase deficiency is an inherited metabolic disorder of biotin recycling that is characterized by neurological and cutaneous abnormalities, and can be successfully treated with biotin supplementation. Sequences of tryptic peptides of the purified human serum enzyme were used to design oligonucleotide primers for polymerase chain reaction amplification from human hepatic total RNA to generate putative biotinidase cDNA fragments. Sequence analysis of a cDNA isolated from a human liver library by plaque hybridization with the largest cDNA probe revealed an open reading frame of 1629 bases encoding a protein of 543 amino acid residues, including 41 amino acids of a potential signal peptide. Comparison of the open reading frame with the known biotinidase tryptic peptides and recognition of the expressed protein encoded by this cDNA by monoclonal antibodies prepared against purified biotinidase demonstrated the identity of this cDNA. Southern analyses suggested that biotinidase is a single copy gene and revealed that human cDNA probes hybridized to genomic DNA from mammals, but not from chicken or yeast. Northern analysis indicated the presence of biotinidase mRNA in human heart, brain, placenta, liver, lung, skeletal muscle, kidney, and pancreas.
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PMID:Human serum biotinidase. cDNA cloning, sequence, and characterization. 750 6

Biotinidase deficiency is an autosomal recessive inherited disorder that is characterized by neurological and cutaneous symptoms. Biotinidase-deficient children cannot recycle endogenous biotin, an essential water-soluble B vitamin. Biotin is covalently attached to epsilon-amino groups of lysyl residues of four carboxylases. These carboxylases are subsequently degraded to biocytin (biotin-epsilon-lysine). Biotinidase cleaves biocytin to biotin and lysine, thereby completing the biotin cycle. The symptoms of biotinidase deficiency can be resolved or prevented by treatment with biotin. Therefore, it is important that biotinidase deficiency is diagnosed early so that permanent neurological damage can be prevented. Many states and countries currently perform newborn screening for biotinidase deficiency. We have recently isolated and characterized the cDNA for normal human biotinidase and localized the gene to chromosome 3p25 (ref. 9). We have now identified the first mutation that causes profound biotinidase deficiency. It occurs in a distinct region of the gene that encodes the putative signal peptide. Fifty percent of symptomatic children studied have a 7-bp deletion coupled with a 3-bp insertion in at least one of their alleles of the biotinidase gene. This mutation appears to be a common cause of biotinidase deficiency in symptomatic children.
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PMID:Mutational hotspot in the human biotinidase gene causes profound biotinidase deficiency. 864 Feb 18

In an attempt to identify a possible defect of mitochondrial metabolism in Rett syndrome we studied 9 girls with typical Rett syndrome using a clinical protocol designed to identify disorders of oxidative metabolism. One girl, (RO) had marked lactic acidemia. Biochemical studies on samples from these patients included leukocyte pyruvate carboxylase assay, serum biotinidase and skin fibroblast pyruvate production, pyruvate dehydrogenase, citrate synthetase and 2-oxoglutarate dehydrogenase assay. Muscle electron transport activities were studied on samples from 4 typical Rett patients including RO. Mitochondrial DNA (mtDNA) mutational analysis for the np3243 MELAS mutation, the np8993 NARP mutation, the np8344 MERFF mutation and the 4977 kb common deletion found in Kearns-Sayre syndrome and aged tissues were tested for in 1 of the muscle samples and 2 blood samples from typical Rett patients. Western blotting of electron transport complex III was performed on mitochondrial samples obtained from autopsy brain tissue in 2 Rett patients and compared to pediatric control brain samples. No abnormalities were found in blood biotinidase or pyruvate carboxylase. Western blotting of 2 Rett brain mitochondrial samples for complex III appear normal. Pyruvate consumption in medium from 8 Rett fibroblast lines grown with and without dichloroacetate (DCA) showed a normal fall in pyruvate suggesting normal pyruvate dehydrogenase activity in these cells, however the fibroblasts from patient RO had a high pyruvate production in culture. Pyruvate dehydrogenase, 2-oxo-glutarate dehydrogenase and citrate synthetase activities in 8 Rett fibroblast lines were normal.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oxidative metabolism in Rett syndrome: 2. Biochemical and molecular studies. 756 65

Ten patients with biotin-dependent, chronic progressive encephalopathies were studied retrospectively. In four patients, the underlying disease was either total or partial deficiency of biotinidase. In one patient, the disease was caused by a lack of holocarboxylase synthetase activity. Four patients presented with Leigh encephalopathy. However, a biochemical defect could not always be confirmed. All patients required the administration of large doses of biotin to maintain normal neurologic function.
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PMID:The clinical spectrum of biotin-treatable encephalopathies in Saudi Arabia. 772 84


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