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)

Biotinidase activities found in porcine brains (n = 3) were as follows: cerebrum, 4.4 +/- 0.2 pmol/min per milligram of protein; cerebellum, 7.6 +/- 0.3 pmol/min per milligram of protein; medulla, 2.9 +/- 0.3 pmol/min per milligram of protein. These values are relatively high compared with the activities in rat or guinea pig brains. Subcellular distribution of biotinidase was found mainly in the soluble cytoplasmic fraction (S3), i.e., in the supernatant of 0.32 M sucrose S2 solution after ultracentrifugation at 105,000g for 90 min. This is in contrast to the guinea pig livers, in which the subcellular distribution of biotinidase is mainly found in the microsomal fraction. After a seven-step purification (22,200-fold enrichment), porcine brain biotinidase is identified as a single polypeptide by the sodium dodecyl sulfate-polyacrylamide gel electrophoresis system, and its molecular weight is determined as 68,000 Da. The isoelectric point of the enzyme was 4.3. Sialidase treatment strongly suggests the presence of sialyl residues in this enzyme. Amino acid analysis indicates relatively high hydrophilicity and high content of glycine and serine. The enzyme activity is inhibited by organic mercurials, but not by diisopropylfluorophosphate. Abundant soluble biotinidase in brain cytoplasm may play an important role which has not been discovered yet.
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PMID:Biotinidase in the porcine cerebrum. 232 94

Guinea pig biotinidase and lipoamidase were mostly located in the liver microsomal fraction. Approx. 80% of the total activities of both enzymes were associated with the membranes subfractions of liver. The subunit molecular masses of these enzymes as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of microsomal biotinidase and lipoamidase were 70 and 60 kDa, respectively. Sephadex G-200 gel-permeation chromatography in the presence of 0.1% Nonidet P-40 indicated that the native-state molecular masses of microsomal biotinidase and lipoamidase were 68 and 120 kDa, respectively. The isoelectric points of microsomal biotinidase and lipoamidase were 6.3 and 5.7, respectively. Linear sucrose density centrifugation analysis indicated that both enzymes exist in the rough endoplasmic reticulum. Comparison of amino acid analyses indicated a higher content of leucine and lower content of serine in lipoamidase than in biotinidase. Microsomal biotinidase and lipoamidase were classified as being thiol-type and serine-type amidases, respectively.
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PMID:Biotinidase and lipoamidase in guinea pig livers. 273 Sep 18

Biotin-binding immunoglobulin (BBI) was recently identified in human serum and has been suggested to have a significant association with allergic and autoimmune disorders. Attempts were made to evaluate the clinical significance of BBI in autoimmune thyroid disorders. Prevalence of BBI was significantly higher in Graves' disease (47%) than in Hashimoto's disease (8%) and healthy controls (10%). The BBI consisted of heterogeneous subtypes with respect to binding of several immunoglobulin classes. Sera in Graves' disease showed predominantly IgG-binding BBI, whereas healthy subjects had IgM-binding BBI. Thyroid stimulating hormone receptor antibody (TRAb) level was significantly higher in the BBI non-detected group than in the detected group. There was no significant relationship between BBI prevalence and thyroid hormone concentrations, anti-thyroglobulin antibody (TGAb) or anti-thyroid microsomal antibody (McAb) titers. In addition, biotin levels in peripheral blood and red blood cells and biotinidase activity did not differ in the BBI detected and non-detected groups. The present results suggest that BBI is associated with autoimmune dysfunction in Graves' disease.
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PMID:Clinical evaluation of biotin-binding immunoglobulin in patients with Graves' disease. 791 19

Lipoamidase (not yet given an EC number) activity was measured in various rat tissues using two different substrates, one natural, lipoyllysine (epsilon-N-(D,L-lipoyl)L-lysine) and one artificial, lipoyl-p-aminobenzoic acid (N-D,L-lipoyl-p-aminobenzoic acid). Biotinidase, EC 3.5.1.12, was measured in the same tissue with the artificial substrate, biotinyl-p-aminobenzoic acid (N-D-biotinyl-p-aminobenzoic acid). Lipoamidase measured as lipoyl-p-aminobenzoic acid hydrolase activity had two pH optima, at pH 6.0 and pH 9.5, in liver homogenate, but only one pH optimum at pH 6.0 in rat plasma. Lipoamidase measured as lipoyllysine hydrolase activity had a pH optimum at pH 5.5 both in liver homogenate and plasma. Similarly, biotinidase shows a single pH optimum at pH 6.0 in liver homogenate and plasma. The properties of lipoyllysine hydrolase and biotinidase were similar with respect to thermostability, pH stability and inhibition pattern, and their properties differed from those of lipoyl-p-aminobenzoic acid hydrolase. Lipoyllysine hydrolase and biotinidase activities were highest in kidney, liver and blood plasma, whereas lipoyl-p-aminobenzoic acid hydrolase activities were highest in liver, brain and kidney. Lipoyllysine hydrolase and biotinidase activities were found mainly in the liver microsomal fraction, and lipoyl-p-aminobenzoic acid hydrolase was recovered from the microsomal fraction and to a small extent from the mitochondrial fraction. These results indicate that liver lipoyl-p-aminobenzoic acid hydrolase is an enzyme protein which differs from lipoyllysine hydrolase, and the data also indicate that liver lipoyllysine hydrolase and biotinidase are the same enzyme protein.
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PMID:Lipoamidase and biotinidase activities in the rat: tissue distribution and intracellular localization. 798 29

Biotinidases from various species ranging from fungi and insects to human have specific amino acids, and regions that are evolutionarily conserved. These specific amino acids and regions are further supported by their homology to a variety of amidases and nitrilases and by the location of missense mutations that cause biotinidase deficiency in humans. Glu-Lys-Cys residues from three of these regions are considered the catalytic triad involved in the catalysis of the amide linkage. The last one-third of the biotinidase sequence is lacking in nitrilases-amidases, which do not bind biocytin or biotin, therefore, it is likely that the biocytin-biotin-binding site of biotinidase is within this portion of the molecule. Although there are many missense mutations at the far C-terminus of the enzyme, the function of this region is still unclear. Biotinidase may have different functions in different cells or in different subcellular compartments. Using computer programs that predict the subcellular localization of proteins based on their N-terminal signal peptides, microsomal localization resulting in secretion was predicted for biotinidase from all species, whereas there is little consistent support for mitochondrial or nuclear localization of the enzymes. Additional immunohistochemical studies of various human tissues at different stages of development are necessary to resolve the ambiguity of subcellular localization of biotinidase.
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PMID:Evolutionary conservation of biotinidase: implications for the enzyme's structure and subcellular localization. 1615 Jun 25