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Characterization of the biotin uptake system encoded by the biotin-inducible bioYMN operon of Corynebacterium glutamicum
Jens Schneider, Petra Peters-Wendisch, K Corinna Stansen, Susanne G?tker, Stanislav Maximow, Reinhard Kr?mer, Volker F Wendisch
BMC Microbiology , 2012, DOI: 10.1186/1471-2180-12-6
Abstract: By comparison of global gene expression patterns of cells grown with limiting or excess supply of biotin or with dethiobiotin as supplement replacing biotin revealed that expression of genes coding for enzymes of biotin ring assembly and for the putative uptake system was regulated according to biotin availability. RT-PCR and 5'-RACE experiments demonstrated that the genes bioY, bioM, and bioN are transcribed from one promoter as a single transcript. Biochemical analyses revealed that BioYMN catalyzes the effective uptake of biotin with a concentration of 60 nM biotin supporting a half-maximal transport rate. Maximal biotin uptake rates were at least five fold higher in biotin-limited cells as compared to cells grown with excess biotin. Overexpression of bioYMN led to an at least 50 fold higher biotin uptake rate as compared to the empty vector control. Overproduction of BioYMN alleviated biotin limitation and interfered with triggering L-glutamate production by biotin limitation.The operon bioYMN from C. glutamicum was shown to be induced by biotin limitation. Transport assays with radio-labeled biotin revealed that BioYMN functions as a biotin uptake system. Overexpression of bioYMN affected L-glutamate production triggered by biotin limitation.Biotin is a vitamin in humans (vitamin H or B7). Biotin deficiency is rarely observed in humans, e.g. after prolonged consumption of raw egg whites that contains biotin-binding avidin [1], as the normal microflora of the large intestine is considered to provide sufficient supply of biotin. If biotin is lacking, multiple carboxylase deficiencies arise [1] because biotin is a cofactor of the biotin-dependent carboxylases, which occur in all domains of life [2]. Many bacteria can synthesize biotin, but biotin auxotrophic bacteria such as Corynebacterium glutamicum require uptake of biotin from the habitat.Biotin synthesis can be subdivided into synthesis of pimelic acid followed by the biotin ring assembly [3]. Biotin ring ass
Post-Marketing Surveillance of Fixed Dose Combination of Methylcobalamin, Alpha Lipoic Acid, Folic Acid, Biotin, Benfotiamine & Vitamin B6-Nutripathy for the Management of Peripheral Neuropathy  [PDF]
Manish Maladkar, Chitra Tekchandani, Urja Dave
Journal of Diabetes Mellitus (JDM) , 2014, DOI: 10.4236/jdm.2014.42019
Abstract:

Background: Peripheral neuropathy is a commonly encountered troublesome condition which is often disabling & worsens when left untreated. Traditional neuropathic pain medications primarily provide symptomatic relief; however, the pathogenesis of nerve damage remains unresolved. Extensive literature survey reveals that patients with peripheral neuropathy experience significant benefits with the use of B-vitamins like methylcobalamin (B12), folic acid (B9), biotin (B7), benfotiamine (B1) and pyridoxine (B6). The other well documented antineuropathic agents include alpha lipoic acid, glutathione, omega fatty acids, myoinositol, certain trace elements, etc. Materials and Methods: A multicentre, prospective, open-label, non-comparative clinical study was carried out in 497 patients with peripheral neuropathy. A fixed dose combination of methylcobalamin, alpha lipoic acid (ALA), folic acid, biotin, benfotiamine & vitamin B6 capsule was orally administered once daily for 12 weeks. Results: Treatment led to significant reduction from baseline score in various neuropathy symptoms from the 4th week itself. After 12 weeks of treatment, the mean pain score declined by 78.0%, numbness by 92.1% and muscle weakness by 96.9%. Also, there was 96.0% & 99.2% reduction in tingling & burning sensation respectively. No serious adverse events were reported.Conclusion: The current study confirms that fixed dose combination of methylcobalamin, ALA, folic acid, biotin, benfotiamine & vitamin B6 is effective & well tolerated in the management of peripheral neuropathy.

Differential effect of biotin on carboxylase activity and mice skeletal muscle metabolism  [PDF]
Marco Antonio Parra Montes de Oca, Gabriel Gutiérrez-Ospina, Pablo Hofmann Salcedo, Alma Lilia Fuentes-Farías, Esperanza Meléndez-Herrera, Margarita Gómez-Chavarín, Armida Báez-Salda?a
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.47A2006
Abstract: In mammalian skeletal muscle there are four carboxylases involved in several biochemical processes like gluconeogenesis, tricarboxylic acid cycle anaplerosis, metabolism of fatty acids and metabolism of various amino acids. It has been shown that biotin deficiency reduces body weight at the expense of muscular mass. When necessary, the liver uses skeletal muscle protein to provide glucose and amino acids to organs in need of such compounds. In this paper we analyzed carboxylase specific activities in hind limb skeletal muscle of 3 weeks old BALB/c male mice, at 0, 1, 4, 7, and 14 days of a specific diet with different biotin concentrations. Biotin was used at 0.0, 1.8 or 98.2 mg per kg of food; and was referred to as biotin deficient, sufficient and supplemented, respectively. Water and food supply and consumption by the three groups of mice were the same. Therefore, the observed effects were directly related to biotin ingestion. The body weight of biotin supplemented mice was the same as the body weight of mice in the biotin sufficient group, while biotin deficiency caused body weight reduction after 7 days of biotin depletion. We found that the total protein concentration in the vastus lateralis muscle is associated with the biotin content in the diet. After 7 days, the muscle total protein content was lower in mice of the biotin deficient group while it was higher in the mice from the biotin supplemented group (P < 0.001). Of the four analyzed enzymes, only pyruvate carboxylase specific activity was reduced in both cases: by consuming the supplemented diet and by the lack of this vitamin. Our data show that PC and muscle metabolism are differentially altered by both, biotin excess and biotin deficiency. The mechanisms of these effects are currently under investigation.
Techniques of Performance Appraisal-A Review  [PDF]
Ashima Aggarwal,Gour Sundar Mitra Thakur
International Journal of Engineering and Advanced Technology , 2013,
Abstract: Performance appraisal system is used in the organizations to measure the effectiveness and efficiency of their employees. Performance Appraisal system is needed because every employee has a different attitude to handle the work. Performance Appraisal tends to improve the work performance, communication expectations, determining employee potential and aiding employee counseling. In this paper we present the review of some popular performance appraisal techniques along with their pros and cons. Ranking, Graphic Rating Scale, Critical Incident, Narrative Essays, Management By Objectives, Assessment Centers, BARS, 360 Degree and 720 Degree are some performance appraisal techniques.
Effects of a rumen protected B vitamin blend substituted for biotin upon milk production and component yield in lactating dairy cows  [PDF]
Essi Evans, David T. Mair
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.32014
Abstract:

Results from 4 switchback field trials involving 608 cows were combined to assess the effects of a protected B vitamin blend (BVB) vs 10 mg of unprotected biotin upon milk yield (kg), fat %, protein %, fat yield (kg) and protein yield (kg) in primiparous and multiparous cows. Trials consisted of 3 DHIA periods executed in the order control-test-control. Cows from 45 to 300 days in milk (DIM) at the start of the experiment that were available for all 3 periods were included in the analysis. No diet changes other than the substitution of 3 grams/cow/day of the BVB for 10 mg of biotin during the test period occurred. Results from the two control periods were compared to results obtained during the test period by individual cow using a paired T test. Results for all cows showed that the provision of the BVB resulted in increased (P < 0.05) milk, fat percentage (%), protein %, fat yield and protein yield. Analysis by age revealed that milk production and milk protein yield were only improved in mature cows. Milk production had a negative effect upon the magnitude of the increase in milk components. The change in milk yield was greatest in early lactation and declined with DIM. Protein % and fat % increased with DIM in mature cows, but not in first lactation cows. Differences in fat yields between test and control feeding periods did not change with DIM, but the improvement in protein yield in mature cows declined with DIM. These results indicate that the BVB provided economically important advantages throughout lactation beyond those witnessed with biotin, but expected results would vary with cow age and stage of lactation.

Determination of biotin content in beet molasses by Lactobacillus plantarum
Lon?ar Eva S.,Do?enovi? Irena S.,Markov Sini?a L.,Malba?a Radomir V.
Acta Periodica Technologica , 2005, DOI: 10.2298/apt0536215l
Abstract: D-biotin content in beet molasses was determined by microbiological method using Lactobacillus plantarum, based on the comparison of the growth of this microorganism in molasses solutions with those in standard solutions of biotin. Incubation of the microorganism was performed on original Vitamin Biotin Testbouillon and laboratory prepared liquid culture medias. The amount of "real" biotin in molasses is low. The results depend upon the sample and volume of molasses solutions. Biotin contents obtained on both liquid media are close.
Overexpression of biotin synthase and biotin ligase is required for efficient generation of sulfur-35 labeled biotin in E. coli
Teegan A Delli-Bovi, Maroya D Spalding, Sean T Prigge
BMC Biotechnology , 2010, DOI: 10.1186/1472-6750-10-73
Abstract: In this study, we produced [35S]-biotin from Na35SO4 and desthiobiotin with a specific activity of 30.7 Ci/mmol, two orders of magnitude higher than previously published methods. The biotinylation domain (PfBCCP-79) from the Plasmodium falciparum acetyl-CoA carboxylase (ACC) was expressed in E. coli as a biotinylation substrate. We found that overexpression of the E. coli biotin synthase, BioB, and biotin ligase, BirA, increased PfBCCP-79 biotinylation 160-fold over basal levels. Biotinylated PfBCCP-79 was purified by affinity chromatography, and free biotin was liberated using acid hydrolysis. We verified that we had produced radiolabeled biologically active [D]-biotin that specifically labels biotinylated proteins through reuptake in E. coli.The strategy described in our report provides a simple and effective method for the production of [35S]-biotin in E. coli based on affinity chromatography.Biotin, or vitamin H, was first identified as a yeast growth factor over 100 years ago[1] and was subsequently isolated from egg yolk[2] and liver[3]. It is an essential cofactor for a small family of enzymes that catalyze carboxylation and decarboxylation reactions, in which biotin serves as a covalent attachment site for CO2[4]. The number of biotinylated proteins varies from one to five in different organisms[5]. Biotin-dependent enzymes include acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase, methylcrotonyl-CoA carboxylase, geranoyl-CoA carboxylase, oxaloacetate decarboxylase, methylmalonyl-CoA decarboxylase, transcarboxylase and urea amidolyase[6]. These enzymes participate in central metabolic processes such as gluconeogenesis, lipogenesis, amino acid metabolism and energy transduction. The most widespread biotin-dependent enzyme is acetyl-CoA carboxylase (ACC)[7], which catalyzes the ATP-dependent transfer of a carboxyl group from carbonate to acetyl-CoA to form malonyl-CoA, in the first committed step of fatty acid biosynthesis[8].ACC is the o
檔案鑒定理論與方法初探 A Preliminary Study of Appraisal Theories and Techniques
Li-kuei Hsueh
Journal of Educational Media & Library Sciences , 1996,
Abstract: 無 This paper mainly discusses appraisal theories and techniques of archives in different countries. Appraisal theories focus on four countries, i.e. United Kingdom, United States, Germany and Norway. In addition, appraisal techniques applied in four countries are discussed, i.e. United Kingdom, United States, China and Russia.
Neurological Manifestations Of Vitamin B12 (Coblamin) Deficiency with a Re-appraisal of its Etiology
Divate p,Patanwala R,Pal V,Pradhan A
Annals of Indian Academy of Neurology , 2003,
Abstract: We undertook a study 25 patients, all clinically suspected to have vitamin B12 deficiency; they were investigated hematologically, biochemically, & by gastric biopsy and MRI. Most of the patients were more than 40 years of age, were either vegetarian or non-vegetarian; 21 patients were belonging to the middle-income group. The total number of males in the study was 22 and there were three females. The clinical features of vitamin B12 deficiency are described. Clinical evidence of pyramidal tract involvement was found in six patients (24%). MRI confirmed cord involvement in 12 of the 17 patients (70.5%): follow up MRI of two patients showed marked reductions in signals after one year of treatment. These patients showed improvement after receiving injectable vitamin b12. Nerve conduction studies (N.C.V) showed evidence of neuropathy in fifteen of eighteen (83%) patients. Gastric biopsy was abnormal in all except one in the 20 patients in whom it was conducted. Anti intrinsic factor blocking antibodies (AIFBA) were elevated in 11/24 (45.8%) and anti parietal cell antibodies (APCAB) were elevated in 19/24 patients (79%). The possible etiological factors responsible for vitamin B12 deficiency are age and pernicious anemia. As concluded in this study, diet was not found to be a contributory factor in the causation of cobalamin deficiency. We conclude that pernicious anemia is probably an important etiological factor as a cause of vitamin B12 deficiency in Indians. The male predominance is intriguing.
Ultrastructural and biochemical detection of biotin and biotinylated polypeptides in Schistosoma mansoni
Brazilian Journal of Medical and Biological Research , 1997, DOI: 10.1590/S0100-879X1997000700003
Abstract: biotinylation is proposed for the identification of surface proteins in schistosoma mansoni using the streptavidin-hrp conjugate for the detection of labeled polypeptides. however, control samples also showed several endogenous biotinylated polypeptides. in an attempt to determine the possibility of nonspecific binding between the streptavidin-hrp conjugate and polypeptides from s. mansoni, the conjugate was blocked with biotinamidecaproate-n-hydroxysuccinimide ester (bcapnhs) before biotin-streptavidin blotting. no bands were detected on the nitrocellulose sheet, demonstrating the specific recognition of biotin by the streptavidin present in the conjugate. whole cercariae and cercarial bodies and tails showed several endogenous biotinylated polypeptides. the biotin concentration was 13 μg/190,000 cercariae. adult worms presented less endogenous biotinylated polypeptides than cercariae. these results may be due to changes in the environment from aerobic to anaerobic conditions when cercarial bodies (schistosomula) are transformed into adult worms and a decrease in co2 production may occur. cercariae, cercarial bodies and adult male worms were examined by transmission electron microscopy employing an avidin-colloidal gold conjugate for the detection of endogenous biotin. gold particles were distributed mainly on the muscle fibers, but dispersed granules were observed in the tegument, mitochondria and cytosol. the discovery of endogenous biotin in s. mansoni should be investigated in order to clarify the function of this vitamin in the parasite
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