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Results for “PANTOTHENIC ACID”

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PubMed1982

Evidence for a single multifunctional polypeptide chain on gramicidin S synthetase 2 obtained from a wild strain and mutant strains of Bacillus brevis.

The structures of the gramicidin S synthetase 2 s (GS 2, heavy enzyme) from a wild strain and mutant strains of Bacillus brevis have been studied by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). The GS 2s used were obtained from a wild strain and group IV of mutant strains (BII-3, BI-3, BI-9) which lacked one specific amino acid activating activity. SDS polyacrylamide gel electrophoresis of GS 2 bound to a radioactive substrate showed that: first, in the case of the wild enzyme, the radioactivity of the substrate amino acid was detected only in the polypeptide with a molecular weight of about 280,000, regardless of the amino acid species used as substrate; secondly, in the case of the mutant enzyme, the radioactivity of the amino acid which could be activated by the enzyme was also associated with the protein band with a molecular weight of about 280,000. Regardless of the enzyme species tested, a pantothenic acid residue was also present in the protein band with a molecular weight of about 280,000. These results suggest that GS 2 is a multifunctional one polypeptide enzyme and the mutant-type GS 2s from BII-3 (proline-lacking), BI-3 (valine-lacking), and BI-9 (leucine-lacking) are also multifunctional enzymes having molecular weights identical to that of the wild-type enzyme.

Amino Acid Isomerases↗
PubMed1984

The Quebec Cooperative Study of Friedreich's Ataxia: 1974-1984--10 years of research.

In this paper the author reviews the progress accomplished in the understanding of Friedreich's disease since the start of the "Quebec Cooperative Study of Friedreich's Ataxia" in 1974. The last ten years have indeed seen important strides taken in the definition and nosography of the hereditary ataxias and the characterization of a number of new entities. Biochemically, the principal leads uncovered during the initial prospective survey, have been pursued to great detail. Unfortunately no clear-cut constant and severe enzyme block in the principal metabolic pathways has yet been identified, despite intensive studies. It is postulated that the defect may instead be a regulatory one and involve a decreased availability or utilization of one of the vitamin cofactors that are known experimentally, or clinically, to produce central nervous system damage with ataxia: Vitamin E, Biotin or Pantothenic Acid. Studies in that direction and in molecular genetics to localize the Friedreich's disease gene are being undertaken for the next phase of the Cooperative Study.

Amino Acids↗
PubMed2006

Mitochondrial function and toxicity: role of the B vitamin family on mitochondrial energy metabolism.

The B vitamins are water-soluble vitamins required as coenzymes for enzymes essential for cell function. This review focuses on their essential role in maintaining mitochondrial function and on how mitochondria are compromised by a deficiency of any B vitamin. Thiamin (B1) is essential for the oxidative decarboxylation of the multienzyme branched-chain ketoacid dehydrogenase complexes of the citric acid cycle. Riboflavin (B2) is required for the flavoenzymes of the respiratory chain, while NADH is synthesized from niacin (B3) and is required to supply protons for oxidative phosphorylation. Pantothenic acid (B5) is required for coenzyme A formation and is also essential for alpha-ketoglutarate and pyruvate dehydrogenase complexes as well as fatty acid oxidation. Biotin (B7) is the coenzyme of decarboxylases required for gluconeogenesis and fatty acid oxidation. Pyridoxal (B6), folate and cobalamin (B12) properties are reviewed elsewhere in this issue. The experimental animal and clinical evidence that vitamin B therapy alleviates B deficiency symptoms and prevents mitochondrial toxicity is also reviewed. The effectiveness of B vitamins as antioxidants preventing oxidative stress toxicity is also reviewed.

Animals↗
PubMed2001

Mass spectrometric studies of trimethylsilylpantothenic acid and related substances.

The characteristic fragment of trimethylsilylated pantothenic acid (TMS-PA) at m/z 291 upon electron ionization was shown to originate from the molecular ion by a McLafferty rearrangement instead of by ejection of 1,1,3,3-tetramethyl-1,3-disilacyclobutane. The verification consisted of labelling experiments and high-resolution mass spectrometry of the fragment and studies on its isotopic distribution. The remaining fragmentation pathways of TMS-PA were clarified by B/E-linked scans and collision-induced dissociation.

Journal Article↗
PubMedDate not supplied

[Influence of adrenal cortex hormones on the process of acetylation].

Tests conducted with intact and adrenalectomized albino rats demonstrated that cortisone and desoxycorticosterone acetate used in doses of 25 and 5 mg/kg, respectively when introduced simultaneously for 7 days tend to significantly intensify the acetylating capacity of the organism. There was no correlation between the intensification of the paraaminobenzoate acetylation and coenzyme "A" content in the tissues and also the pantothenic acid utilization.

Acetylation↗
PubMed1986

Transport and metabolism of vitamins.

Although the biochemical roles of most vitamins in the body are reasonably well understood, our knowledge of how the body transports and metabolizes the vitamins is incomplete. This paper summarizes the information available on riboflavin, vitamin B-6, biotin, vitamin D, vitamin C, and pantothenic acid. As might be expected on the basis of the diverse chemistry and biology of these substrates, the body has quite unique mechanisms for handling each of them.

Animals↗
PubMed1978

Kinetic study on the reaction mechanism of pantothenase: existence of an acyl-enzyme intermediate and role of general acid catalysis.

A kinetic study was performed on the reaction mechanism of pantothenase (EC 3.5.1.22) catalyzed hydrolysis of the pantothenic acid. A nonlinear progress curve is derived if the reaction occurs at low buffer concentrations. The nonlinearity is due to partial reversibility of the reaction; an acylenzyme (pantoyl-enzyme) is formed during the reaction, and beta-alanine, the other end product, is able to react with the acyl-enzyme and return back to pantothenate. The dependence of the beta-alanine return reaction on buffer concentration and on pH suggests a general acid catalysis during the reaction. A reaction mechanism is suggested, in which the -NH3+ form of beta-alanine participates in the return reaction, and the deacylation of the acyl-enzyme is acid catalyzed.

Acylation↗
PubMed2005

Coenzyme A: back in action.

Coenzyme A (CoA) is a ubiquitous essential cofactor that plays a central role in the metabolism of carboxylic acids, including short- and long-chain fatty acids. In the last few years, all of the genes encoding the CoA biosynthetic enzymes have been identified and the structures of several proteins in the pathway have been determined. CoA is assembled in five steps from pantothenic acid and pathway intermediates are common to both prokaryotes and eukaryotes. In spite of the identical biochemistry, remarkable sequence differences among some of the prokaryotic and eukaryotic enzymes have been revealed by comparative genomics. Renewed interest in CoA has arisen from the realization that the biosynthetic pathway is a target for antibacterial drug discovery and from the unexpected association of a human neurodegenerative disorder with mutations in pantothenate kinase. The purpose of this review is to integrate previous knowledge with the most recent findings in the genetics, enzymology and regulation of CoA biosynthesis in bacteria, plants and mammals.

Animals↗
PubMed1984

Differential effects of cysteine on protein and coenzyme A synthesis in rat heart.

The effect of cysteine availability on protein and coenzyme A (CoA) synthesis in perfused rat heart was incompletely evaluated in earlier experiments because rapid conversion of cysteine to cystine occurred when the perfusion buffer was oxygenated. This conversion was minimized by addition of an excess of reducing agents such as dithiothreitol or mercaptodextran or by provision of bathocuproine disulfonate, a copper chelator. Dithiothreitol was not a suitable protective agent because it reduced ATP and creatine phosphate contents. Perfusion of hearts with [35S]cystine or [35S]cysteine in the presence of mercaptodextran resulted in a 22-fold or 5-fold increase, respectively, in incorporation of [35S] into protein and a 5-fold or 8-fold increase, respectively, in incorporation into CoA compared with hearts supplied [35S]cystine or [35S]cysteine without the reducing agent. When compared with hearts perfused at an aortic pressure of 90 mmHg with bicarbonate buffer that contained 15 mM glucose, 25 mU insulin/ml, 0.4 mM [14C]phenylalanine, no cysteine and plasma levels of other amino acids, provision of 0.09 or 0.2 mM cysteine alone or in the presence of mercaptodextran, or bathocuproine disulfonate enhanced rates of protein synthesis 16-35%. When 0.2 mM cysteine was added to bicarbonate buffer containing 7 microM pantothenic acid, supplementation with mercaptodextran or bathocuproine disulfonate was required to raise CoA content. These results indicated that an exogenous supply of cysteine was needed to maintain maximal rates of protein and CoA synthesis in the perfused rat heart. Protective compounds were required to obtain the cysteine effect on CoA but not on protein synthesis.

Animals↗
PubMed1979

Nutrient requirements of rat embryos undergoing organogenesis in vitro.

Rat embryos at the head-fold stage were cultured in rotating bottles for 2 days in rat serum extensively dialysed against glucose-free BSS, and to which various energy sources and nutrients were added. Optimum growth and differentiation, virtually indentical with that obtained in while serum and to that seen during the corresponding period in vivo, were obtained with the addition of glucose and certain vitamins: pantothenic acid and riboflavin had a general beneficial effect on development, i-inositol suppressed neural tube defects, and folic acid significantly improved growth of the embryos.

Animals↗
PubMed1971

Multivalent repression and genetic depression of isoleucine-valine biosynthetic enzymes in Serratia marcescens.

The regulation of the formation of isoleucine-valine biosynthetic enzymes was examined to elucidate the mechanism of isoleucine-valine accumulation by alpha-aminobutyric acid-resistant (abu-r) mutants of Serratia marcescens. In the isoleucine-valine auxotroph, l-threonine dehydratase, acetohydroxy acid synthetase, and transaminase B were repressed when isoleucine, valine, and leucine were simultaneously added to minimal medium. These enzymes were derepressed at the limitation of any single branched-chain amino acid. Pantothenate, which stimulated growth of this auxotroph, had no effect on the enzyme levels. It became evident from these results that in S. marcescens isoleucine-valine biosynthetic enzymes are subject to multivalent repression by three branched-chain amino acids. The abu-r mutants had high enzyme levels in minimal medium, with or without three branched-chain amino acids. Therefore, in abu-r mutants, isoleucine-valine biosynthetic enzymes are genetically derepressed. This derepression was considered to be the primary cause for valine accumulation and increased isoleucine accumulation.

Cell-Free System↗
PubMed1976

Biosynthesis of sphingomyelin in rat liver endoplasmic reticulum.

Rat liver microsomal sphingomyelin synthetase (CDPcholine: N-acylspingosine choline phosphotransferase (EC 2.7.8.3)) has been shown to be markedly stimulated by ATP and pantothenic acid derivatives such as CoA, pantethine, pantetheine and 4'-phosphopantetheine.

Animals↗
PubMed1976

[Acetylation reaction in mice in the normal state and in tumors].

Studies of peculiarities of acetylation with the use of sulfadimidine showed the distribution of female white non-bred mice into two groups - with high and low activity. In C3H/He mice a relatively high activity of sulfadimidine acetylation was observed, while in C57BL/He mice a low activity of acetylation was noted. The growth of transplanted melanoma B-16 in C57BL/He mice and sarcoma 37 and sarcoma 180 in non-bred mice resulted in an increased activity of sulfadimidine acetylation. The use of w-sodium methylpantothenate (an antagonist of pantothenic acid) failed to show an increased activity of sulfadimidine acetylation and inhibited the tumor growth.

Acetylation↗
PubMed2005

Characterization of a new pantothenate kinase isoform from Helicobacter pylori.

Pantothenate kinase (PanK) catalyzes the first step in the biosynthesis of the essential and ubiquitous cofactor coenzyme A (CoA) in all organisms. Two well characterized isoforms of the enzyme are known: a prokaryotic PanK that predominates in eubacteria and a eukaryotic isoform that has primarily been characterized from mammalian and plant sources. Curiously, the genomes of certain pathogenic bacteria, including Helicobacter pylori and Pseudomonas aeruginosa, do not contain a PanK similar to either isoform, although these organisms possess all the other biosynthetic machinery required for CoA production. In this study we cloned, overexpressed and characterized an enzyme from Bacillus subtilis and its homologue from H. pylori and show that they catalyze the ATP-dependent phosphorylation of pantothenate. These enzymes do not share sequence homology with any known PanK, and unlike the bacterial and eukaryotic PanK isoforms their activity is not regulated by either CoA or acetyl-CoA. They also do not accept the pantothenic acid antimetabolite N-pentylpantothenamide as a substrate or are inhibited by it. Taken together, these results point to the identification of a third distinct isoform of PanK that accounts for the only known activity of the enzyme in pathogens such as H. pylori and P. aeruginosa.

Acetyl Coenzyme A↗
PubMed1991

[Hyperlipidemia: physiopathology and our experience in the ambulatory care of 3 groups of patients undergoing blood lipid normalization treatment].

The authors tested the efficacy of three different lipid-lowering drugs in subjects with more or less severe alterations of the lipoprotein pattern. All subjects were submitted to blood tests prior to and at the end of treatment with special attention to the trend of the lipid pattern, assaying cholesterol, HDL, LDL, triglyceride, total lipid blood levels and lipid electrophoresis. The drugs employed were: pantothenic acid, sulodexide, and DEAE-dextran.

Adult↗
PubMed1987

Biotin transport through the blood-brain barrier.

The unidirectional influx of biotin across cerebral capillaries, the anatomical locus of the blood-brain barrier, was measured with an in situ rat brain perfusion technique employing [3H]biotin. Biotin was transported across the blood-brain barrier by a saturable system with a one-half saturation concentration of approximately 100 microM. The permeability-surface area products were 10(-4) s-1 with a biotin concentration of 0.02 microM in the perfusate. Probenecid, pantothenic acid, and nonanoic acid but not biocytin or biotin methylester (all 250 microM) inhibited biotin transfer through the blood-brain barrier. The isolated rabbit choroid plexus was unable to concentrate [3H]biotin from medium containing 1 nM [3H]biotin. These observations provide evidence that: biotin is transported through the blood-brain barrier by a saturable transport system that depends on a free carboxylic acid group, and the choroid plexus is probably not involved in the transfer of biotin between blood and cerebrospinal fluid.

Animals↗
PubMed1996

Effect of vitamins on the aerobic degradation of 2-chlorophenol, 4-chlorophenol, and 4-chlorobiphenyl.

The effect of vitamins on the aerobic degradation and dechlorination of 2-chlorophenol and 4-chlorophenol by Pseudomonas pickettii, strain LD1, and 4-chlorobiphenyl by Pseudomonas sp. strain CPE1 was determined. These microorganisms are capable of using the target compounds as the sole carbon and energy source, but do not need vitamins to metabolize them. The addition to the culture medium of a vitamin solution containing biotin, folic acid, pyridoxine hydrochloride, riboflavin, thiamine hydrochloride, niacin, pantothenic acid, cyanocobalamin, p-aminobenzoic acid, and thioctic acid (total final concentration: < or = 600 ppb) resulted in a 7%-16% increase in the amount of target compounds degraded over the incubation period required for the concentration of the compound in the cultures to drop to approximately zero. A corresponding increase in the amount of chloride ion produced was also detected during the same period, indicating active (and often stoichiometric) dechlorination of the target compounds.

Aerobiosis↗