Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.4.1.1 (pyruvate carboxylase)
 1,516 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activities of pyruvate and propionyl CoA carboxylase in chicken tissues during normal growth and biotin deficiency were investigated. In normal growing chickens, liver and kidney pyruvate carboxylase activity was high and varied with age. The activity in heart and brain was low and remained relatively constant throughout the experimental period. Propionyl CoA carboxylase activity in kidney and heart appeared to increase with age but remained unchanged in liver and brain. Biotin deficiency progressively decreased both pyruvate and propionyl CoA carboxylase activities in liver, kidney, heart and brain. Most marked effects were observed in liver and kidney.
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PMID:Activities of pyruvate and prionyl Coenzyme A carboxylase in chicken tissues during normal growth and biotin deficiency. 61 93

Varying degrees of biotin deficiency were induced by adding freeze-dried, raw egg white to the diet of broiler chicks. Aspects of liver metabolism were studied with reference to fatty liver and kidney syndrome. Mortality was low with 11.8 g egg white/kg diet, or less, but with 17.7 g/kg or more, mortality was very high. High mortality was observed with less than 0.33 microgram biotin/g liver. Associated with low concentrations of liver biotin were substantial increases in liver weight and lipid content in starved birds. The increased liver lipid content was not observed in birds fed ad libitum. The increased liver lipid content in biotin-deficient, starved birds was not reflected in the specific activities of hepatic lipogenic enzymes or hepatic lipogenesis in vivo measured by the incorporation of tritium from 3H-labelled water into liver lipid. Biotin deficiency affected the specific activities of the biotin-requiring enzymes, pyruvate carboxylase and acetyl CoA carboxylase, differently; the latter was unaffected whereas the former decreased concomitantly with liver biotin concentration.
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PMID:Biotin deficiency and liver metabolism in relation to fatty liver and kidney syndrome. 67 52

Biotin deficiency can be induced readily in monogastric animals and is accompanied by characteristic abnormalities. These include dermal lesions involving hyper- and parakeratosis and, in fur-bearing animals, alopecia and achromatricia. Biochemical changes include depressions in the activities of biotin-dependent enzymes and the metabolic pathways in which they are involved. However, it has been shown in chickens that the relative changes in the activities of these enzymes and the resultant manifestations of the deficiency can be markedly influenced by the dietary content of other nutrients such as protein or fat. Biochemical criteria are required for the diagnosis of subclinical deficiency and these are best-established for poultry. Blood pyruvate carboxylase activity is a good criterion in young birds. Biotin-responsive disorders have been identified in several species. The etiology of fatty liver and kidney syndrome in chickens is now largely understood and is an interesting example of how a combination of nutritional and environmental factors can result in sudden death in, until then, apparently healthy animals.
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PMID:Assessment of biotin deficiency in animals. 286 81

1. Chicks were fed on biotin-deficient low- and high-protein diets supplemented with increasing concentrations of biotin. 2. Biotin deficiency decreased hepatic activity of pyruvate carboxylase [EC 6.4.1.1] but activity of acetyl-CoA carboxylase [EC 6.4.1.2] was comparatively unaffected. 3. Increasing dietary protein increased the severity of biotin deficiency as assessed by skin lesions and decreased plasma biotin concentrations. 4. The severity of the skin lesions over all the treatments was most closely related to plasma biotin concentration.
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PMID:Aspects of metabolism related to the occurrence of skin lesions in biotin-deficient chicks. 731 13

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 weight loss in the mice receiving the biotin-deficient diet. In the livers of biotin-deficient mice, the specific activities of two biotin-dependent enzymes--pyruvate carboxylase and propionyl-CoA carboxylase--decreased by as much as 75% and 80%, respectively, and in spleen lymphocytes the specific activities of these two enzymes decreased by 63% and 75%, respectively. With respect to the effects of biotin deficiency on the immune system, we observed statistically significant changes in both the absolute number of spleen cells and in the proportions of spleen cells carrying different phenotypic markers: after 16 wk the percentage of cells expressing surface immunoglobulin (sIg) decreased from 47% (control and supplemented) to 27% (deficient) and CD3+ cells increased from 42% (control and supplemented) to 54% (deficient). The mitogen-induced proliferation of spleen cells from deficient mice was lower than that of spleen cells from the control mice. These findings suggest that biotin could have an important role in lymphocyte maturation and responsiveness to stimulation, and consequently in the capacity of the immune system to respond to an antigenic challenge.
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PMID:Biotin deficiency induces changes in subpopulations of spleen lymphocytes in mice. 949 86

The metabolism of glucose is deranged in thiamin deficiency, but once any deficiency has been corrected there is no further effect of increased thiamin intake on the ability to metabolize glucose through either pyruvate dehydrogenase (EC 1.2.4.1) and the citric acid cycle, or the pentose phosphate pathway, in which transketolase (EC 2.2.1.1) is the thiamin-dependent step. It has been suggested that the Wernicke-Korsakoff syndrome is associated with a genetic variant of transketolase which requires a higher than normal concentration of thiamin diphosphate for activity. This finding would suggest that there may be a group of the population who have a higher than average requirement for thiamin, but the evidence is not convincing. There are no estimates of biotin requirements, but either coenzyme saturation of erythrocyte pyruvate carboxylase, or the excretion of 3-hydroxy-isovalerate (perhaps after a test dose of leucine) could be used to assess requirements in depletion-repletion studies. Biotin deficiency leads to impaired glucose tolerance, but it is unlikely that glucose tolerance could be used to assess optimum biotin status, since other more common factors affect glucose tolerance to a greater extent. Plasma triacylglycerol and nonesterified fatty acids are moderately elevated in pantothenic acid deficiency. However, this is unlikely to be useful in assessing pantothenate status, since again, other more common factors affect plasma lipids. To date there are no biochemical indices of adequate pantothenate nutrition, and no estimates of requirements.
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PMID:Optimum nutrition: thiamin, biotin and pantothenate. 1046 87

Biotin is a water soluble enzyme cofactor that belongs to the vitamin B complex. In humans, biotin is involved in important metabolic pathways such as gluconeogenesis, fatty acid synthesis, and amino acid catabolism by acting a as prosthetic group for pyruvate carboxylase, propionyl-CoA carboxylase, beta-methylcrotinyl-CoA carboxylase, and acetyl-CoA carboxylase. Carboxylases are synthesized as apo-carboxylases without biotin and the active form is produced by their covalent binding of biotin to the epsilon-amino group of a lysine residue of the apocarboxylases. This reaction is catalyzed by the holo-carboxylase synthetase. The last step in the degradation of carboxylases, the cleavage of the biotinyl moiety from the epsilon-amino group lysine residues, is catalyzed by biotinidase and results in the release of free biotin, which can be recycled. Biotin regulates the catabolic enzyme propionyl-CoA carboxylase at the posttranscriptional level whereas the holo-carboxylase synthetase is regulated at the transcriptional level. Aside from its role in the regulation of gene expression of carboxylases, biotin has been implicated in the induction of the receptor for the asialoglycoprotein, glycolytic enzymes and of egg yolk biotin binding proteins. Biotin deficiency in humans is extremely rare and is generally associated with prolonged parenteral nutrition, the consumption of large quantities of avidin, usually in the form of raw eggs, severe malnutrition and, inherited metabolic disorders. In humans, there are autosomal recessive disorders of biotin metabolism that result from the disruption of the activity of biotinidase or holo-carboxylase synthetase.
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PMID:[Importance of biotin metabolism]. 1084 44

Biotin deficiency in experimental animals causes low body weight as well as several phenomena suggestive of an altered immune system. We reported previously that chronic biotin deficiency in mice decreases body weight and alters the number and proportion of lymphocyte subpopulations in the spleen. To further characterize the effects of biotin deficiency, we studied in detail the maturation of thymocytes and the status of biotin in the thymus, as well as the body length of biotin-deficient mice. Male Balb/cAnN mice were fed for up to 20 wk either standard control diet, a biotin-deficient diet, or a biotin-sufficient diet. At different times, nose-rump length, weight of the thymus, spleen and liver, total number of cells in the spleen and thymus, pyruvate carboxylase (PC) and propionyl CoA carboxylase (PCC) activity in thymus cells, and the proportion of distinct thymocyte subsets were determined. These variables did not differ between mice fed the control and biotin-sufficient diets. In contrast, biotin-deficient mice differed from biotin-sufficient mice in all of the analyzed variables. PC and PCC specific activities of thymocytes of mice fed the biotin-depleting diet decreased during the first 4 wk by 84.5%. The maturation of thymocytes in biotin-deficient mice was arrested at the double-negative stage. Our results suggest that biotin deficiency in mice causes an accelerated involution of the thymus and decreases nose-rump length, but these effects do not correlate in magnitude or in temporality with the sharp decrease in the activity of the biotin-dependent carboxylases. As such, the possibility that the aforementioned effects are not related directly to the prosthetic function of biotin should be considered.
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PMID:Biotin deficiency blocks thymocyte maturation, accelerates thymus involution, and decreases nose-rump length in mice. 1528 85

In evaluating potential indicators of biotin status, we quantitated the expression of biotin-related genes in leukocytes from human blood of normal subjects before and after inducing marginal biotin deficiency. Biotin deficiency was induced experimentally by feeding an egg-white diet for 28 d. Gene expression was quantitated for the following biotin-related proteins: methylcrotonyl-CoA carboxylase chains A (MCCA) and B (MCCB); propionyl-CoA carboxylase chains A (PCCA) and B (PCCB); pyruvate carboxylase (PC); acetyl-CoA carboxylase isoforms A (ACCA) and B (ACCB); holocarboxylase synthetase (HCS); biotinidase; and 2 potential biotin transporters: sodium-dependent multivitamin transporter (SMVT) and solute carrier family 19 member 3 (SLC19A3). For 7 subjects who successfully completed the study, the abundance of the specific mRNAs was determined by quantitative real-time RT-PCR at d 0 and 28. At d 28, SLC19A3 expression had decreased to 33% of d 0 (P < 0.02 by two-tailed, paired t test). Expression of MCCA, PCCA, PC, ACCA, ACCB, HCS, biotinidase, and SMVT decreased to approximately 80% of d 0 (P < 0.05). Expression of the MCCB and PCCB chains that do not carry the biotin-binding motif did not change significantly; we speculate that expression of the biotin-binding chains of biotin-dependent carboxylases is more responsive to biotin status changes. These data provide evidence that expression of SLC19A3 is a relatively sensitive indicator of marginal biotin deficiency.
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PMID:Biotin deficiency reduces expression of SLC19A3, a potential biotin transporter, in leukocytes from human blood. 1562 30

Marginal maternal biotin deficiency reduces hepatic activity of biotin-dependent carboxylases and causes high rates of fetal birth defects in mice. We tested the hypothesis that the decreased carboxylase activity observed in deficient dams and their offspring is mediated by decreased abundance of biotinylated carboxylases, decreased expression of their mRNAs, or both. During gestation, CD-1 mice were fed a diet that induced biotin deficiency or a biotin-sufficient diet. On gestational d 17, gravid uteri were removed, and each live fetus was examined grossly for defects. The expected high incidence of cleft palate (83%) in offspring was observed. In maternal and fetal liver, acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase, and beta-methylcrotonyl-CoA carboxylase abundances were determined by Western blotting; the content of mRNAs for most of these enzymes and holocarboxylase synthetase was determined by real-time RT-PCR. Biotin deficiency significantly reduced the abundance of the carboxylases in maternal and fetal liver; neither the content of mRNAs for the carboxylases nor holocarboxylase synthetase changed. This study provides evidence that the decrease in carboxylase activities is attributable to a decrease in the abundance of biotinylated carboxylases; further, this effect is more severe in fetuses than dams.
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PMID:Marginal maternal biotin deficiency in CD-1 mice reduces fetal mass of biotin-dependent carboxylases. 1586 67


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