Biotinidase (BTD)
The protein contains 543 amino acids for an estimated molecular weight of 61133 Da.
Catalytic release of biotin from biocytin, the product of biotin-dependent carboxylases degradation. (updated: April 14, 2009)
Protein identification was indicated in the following studies:
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
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Cellular Component
Extracellular exosome
Extracellular region
Extracellular space
Mitochondrial matrix
The reference OMIM entry for this protein is 253260
Biotinidase deficiency multiple carboxylase deficiency, late-onset
Multiple carboxylase deficiency, juvenile-onset
Btd deficiency
A number sign (#) is used with this entry because biotinidase deficiency, a form of multiple carboxylase deficiency, is caused by homozygous or compound heterozygous mutation in the BTD gene (609019) on chromosome 3p25.
DESCRIPTION
Multiple carboxylase deficiency (MCD) is an autosomal recessive metabolic disorder characterized primarily by cutaneous and neurologic abnormalities. Symptoms result from the patient's inability to reutilize biotin, a necessary nutrient. Sweetman (1981) recognized that multiple carboxylase deficiency could be classified into early (see 253270) and late forms. The early form showed higher urinary excretion of 3-hydroxyisovaleric acid and 3-hydroxypropionic acid than the late form and was associated with normal plasma biotin concentrations. Sweetman (1981) proposed a defect in holocarboxylase synthetase and intestinal biotin absorption, respectively. Some patients with biotinidase deficiency present in infancy (Baumgartner et al., 1985; Kalayci et al., 1994), and some individuals with this deficiency are asymptomatic (Wolf et al., 1997).CLINICAL FEATURES
Gompertz et al. (1971) reported a patient with biotin-responsive beta-methylcrotonylglycinuria who had a deficiency of 3-methylcrotonyl-CoA carboxylase (Gompertz et al., 1973). On restudy of this patient, Sweetman et al. (1977) found that the patient was severely ketoacidotic, responded both clinically and biochemically to biotin, and excreted tiglylglycine, a metabolite of isoleucine that is excreted by patients with propionic acidemia due to propionyl-CoA carboxylase deficiency (606054). The deficiency of 2 mitochondrial carboxylases, both containing biotin, suggested that the fundamental defect was either in the transport of biotin or in the holocarboxylase synthetase that attaches biotin covalently to both carboxylases. Charles et al. (1979) reported a presumed case of biotinidase deficiency in a 10-month-old boy who presented with dermatitis, alopecia, severe hypotonia, and developmental regression. Urinary organic acid analysis showed high levels of 3-hydroxyisovaleric acid, beta-methylcrotonylglycine, and 3-hydroxypropionic acid. Activities of propionyl CoA-carboxylase, beta-methylcrotonyl CoA-carboxylase, and pyruvate carboxylase in cultured fibroblasts were normal. Treatment with oral biotin resulted in a dramatic clinical improvement, and the authors postulated a defect in biotin absorption or transport. Lehnert et al. (1979) described a 10-week-old girl with hypotonia, recurrent seizures, and 3-methylcrotonylglycine and 3-hydroxyisovaleric acid in the urine. She also had small, but pathologic amounts of urinary propionic acid and methylcitric acid, suggesting a defect in the metabolism of biotin. Clinically and metabolically, the child responded to biotin. Bartlett et al. (1980) reported a child with a combined deficiency of propionyl-CoA carboxylase, 3-methlycrotonyl-CoA carboxylase, and pyruvate carboxylase. Cultured fibroblasts responded to administration of biotin. The primary defect was thought to involve either biotin metabolism or its intracellular transport. Sander et al. (1980) reported a family with biotin-responsive MCD. Affected children presented with a skin rash, infections, acute intermittent ataxia, and lactic acidosis. Postmortem examination of 1 patient showed atrophy of the superior vermis of the cerebellum, similar to that seen in chronic alcoholism. Wolf et al. (1983) reported 3 children with late-onset mul ... More on the omim web site
Feb. 22, 2019: Protein entry updated
Automatic update: comparative model was added.
Feb. 22, 2019: Protein entry updated
Automatic update: model status changed
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).
Oct. 19, 2018: Protein entry updated
Automatic update: OMIM entry 253260 was added.