scholarly journals Lactobacillus casei 64H Contains a Phosphoenolpyruvate-Dependent Phosphotransferase System for Uptake of Galactose, as Confirmed by Analysis of ptsH and Differentgal Mutants

1999 ◽  
Vol 181 (1) ◽  
pp. 225-230 ◽  
Author(s):  
Katja Bettenbrock ◽  
Ulrike Siebers ◽  
Petra Ehrenreich ◽  
Carl-Alfred Alpert
Keyword(s):  
Thin Layer ◽  
Positive Selection ◽  
Lactobacillus Casei ◽  
Phosphotransferase System ◽  
Galactose Metabolism ◽  
Induction Kinetics ◽  
Leloir Pathway ◽  
Reduced Rate ◽  
Layer Chromatography

ABSTRACT Galactose metabolism in Lactobacillus casei 64H was analyzed by genetic and biochemical methods. Mutants with defects inptsH, galK, or the tagatose 6-phosphate pathway were isolated either by positive selection using 2-deoxyglucose or 2-deoxygalactose or by an enrichment procedure with streptozotocin.ptsH mutations abolish growth on lactose, cellobiose,N-acetylglucosamine, mannose, fructose, mannitol, glucitol, and ribitol, while growth on galactose continues at a reduced rate. Growth on galactose is also reduced, but not abolished, ingalK mutants. A mutation in galK in combination with a mutation in the tagatose 6-phosphate pathway results in sensitivity to galactose and lactose, while a galK mutation in combination with a mutation in ptsH completely abolishes galactose metabolism. Transport assays, in vitro phosphorylation assays, and thin-layer chromatography of intermediates of galactose metabolism also indicate the functioning of a permease/Leloir pathway and a phosphoenolpyruvate-dependent phosphotransferase system (PTS)/tagatose 6-phosphate pathway. The galactose-PTS is induced by growth on either galactose or lactose, but the induction kinetics for the two substrates are different.

Phytochemical, Analytical and Medicinal Studies of Holoptelea integrifolia Roxb. Planch - A Review

2019 ◽  
Vol 5 (4) ◽  
pp. 270-277 ◽  
Author(s):  
Vijay Kumar ◽  
Simranjeet Singh ◽  
Ragini Bhadouria ◽  
Ravindra Singh ◽  
Om Prakash
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Biologically Active ◽  
Toxicological Studies ◽  
Wide Range ◽  
Layer Chromatography

Holoptelea integrifolia Roxb. Planch (HI) has been used to treat various ailments including obesity, osteoarthritis, arthritis, inflammation, anemia, diabetes etc. To review the major phytochemicals and medicinal properties of HI, exhaustive bibliographic research was designed by means of various scientific search engines and databases. Only 12 phytochemicals have been reported including biologically active compounds like betulin, betulinic acid, epifriedlin, octacosanol, Friedlin, Holoptelin-A and Holoptelin-B. Analytical methods including the Thin Layer Chromatography (TLC), High-Performance Thin Layer Chromatography (HPTLC), High-Performance Liquid Chromatography (HPLC) and Liquid Chromatography With Mass Spectral (LC-MS) analysis have been used to analyze the HI. From medicinal potency point of view, these phytochemicals have a wide range of pharmacological activities such as antioxidant, antibacterial, anti-inflammatory, and anti-tumor. In the current review, it has been noticed that the mechanism of action of HI with biomolecules has not been fully explored. Pharmacology and toxicological studies are very few. This seems a huge literature gap to be fulfilled through the detailed in-vivo and in-vitro studies.

scholarly journals Towards Enhanced Galactose Utilization by Lactococcus lactis

2010 ◽  
Vol 76 (21) ◽  
pp. 7048-7060 ◽  
Author(s):  
Ana R. Neves ◽  
Wietske A. Pool ◽  
Ana Solopova ◽  
Jan Kok ◽  
Helena Santos ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Poor Quality ◽  
Genetically Engineered ◽  
Phosphotransferase System ◽  
Galactose Metabolism ◽  
Gene Encoding ◽  
Leloir Pathway ◽  
Lactose Fermentation ◽  
Consumption Rates ◽  
Galactose Utilization

ABSTRACT Accumulation of galactose in dairy products due to partial lactose fermentation by lactic acid bacteria yields poor-quality products and precludes their consumption by individuals suffering from galactosemia. This study aimed at extending our knowledge of galactose metabolism in Lactococcus lactis, with the final goal of tailoring strains for enhanced galactose consumption. We used directed genetically engineered strains to examine galactose utilization in strain NZ9000 via the chromosomal Leloir pathway (gal genes) or the plasmid-encoded tagatose 6-phosphate (Tag6P) pathway (lac genes). Galactokinase (GalK), but not galactose permease (GalP), is essential for growth on galactose. This finding led to the discovery of an alternative route, comprising a galactose phosphotransferase system (PTS) and a phosphatase, for galactose dissimilation in NZ9000. Introduction of the Tag6P pathway in a galPMK mutant restored the ability to metabolize galactose but did not sustain growth on this sugar. The latter strain was used to prove that lacFE, encoding the lactose PTS, is necessary for galactose metabolism, thus implicating this transporter in galactose uptake. Both PTS transporters have a low affinity for galactose, while GalP displays a high affinity for the sugar. Furthermore, the GalP/Leloir route supported the highest galactose consumption rate. To further increase this rate, we overexpressed galPMKT, but this led to a substantial accumulation of α-galactose 1-phosphate and α-glucose 1-phosphate, pointing to a bottleneck at the level of α-phosphoglucomutase. Overexpression of a gene encoding α-phosphoglucomutase alone or in combination with gal genes yielded strains with galactose consumption rates enhanced up to 50% relative to that of NZ9000. Approaches to further improve galactose metabolism are discussed.

STEROID EXCRETION AND BIOSYNTHESIS, WITH SPECIAL REFERENCE TO ANDROST-16-ENES, IN A WOMAN WITH A VIRILISING ADRENOCORTICAL CARCINOMA

1969 ◽  
Vol 60 (2) ◽  
pp. 265-275 ◽  
Author(s):  
D. B. Gower ◽  
Margaret I. Stern
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Adrenocortical Carcinoma ◽  
Gas Liquid Chromatography ◽  
Adrenal Carcinoma ◽  
Peripheral Plasma ◽  
Steroid Excretion ◽  
Layer Chromatography ◽  
Free Steroid

ABSTRACT The level of 3α-hydroxy-5α-androst-16-ene (Δ16-androstenol) excreted as glucuronide in the urine of a woman with virilising adrenal carcinoma was measured by gas-liquid chromatography (GLC) of the free steroid and its chloromethyl dimethyl silyl (CMDS) ether and found to be 1.46 mg/day. On the basis of thin-layer chromatography (TLC) and GLC of free steroid and derivatives, Δ16-androstenol has also been tentatively identified in the urinary sulphate fraction and in peripheral plasma. The values were approx. 0.6 mg/d and 2.8 μg/100 ml respectively. After operation, the amount of urinary Δ16-androstenol (as glucuronide) fell to a low level; none was detected in plasma or in urine (as sulphate). Levels of other steroids in the urine and plasma were consistent with the clinical diagnosis of virilising adrenal carcinoma. After operation, the excretion of most of these steroids had reverted to values which were normal or lower. In vitro, the cancerous adrenal tissue metabolised 4-14C-pregnenolone to 3β-hydroxy-androsta-5,16-diene (0.2 %) and 4-14C-progesterone to a small quantity (< 0.03 %) of androsta-4,16-dien-3-one. No androst-16-enes were formed from radioactive dehydroepiandrosterone (DHA) or testosterone. The formation of other labelled metabolites confirmed studies by earlier workers.

THE ACTION OF DIBUTYRYL CYCLIC 3′,5′-ADENOSINE MONOPHOSPHATE ON THE MOUSE THYROID GLAND IN VITRO

1970 ◽  
Vol 47 (3) ◽  
pp. 333-338 ◽  
Author(s):  
PAT KENDALL-TAYLOR ◽  
D. S. MUNRO
Keyword(s):  
Thyroid Gland ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Adenosine Monophosphate ◽  
Thyroid Stimulating Hormone ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Layer Chromatography ◽  
Mouse Thyroid

SUMMARY The effects of dibutyryl cyclic 3′,5′-adenosine monophosphate (DBc-AMP) on the mouse thyroid gland have been investigated in the in-vitro assay of Brown & Munro (1967). The distribution of 131I-labelled compounds in the glands and the supporting medium have been analysed by thin-layer chromatography and the changes induced by cyclic 3′,5′-adenosine monophosphate (c-AMP), DBc-AMP or thyroid-stimulating hormone (TSH) compared. The release of 131I was increased when the glands were incubated with DBc-AMP, c-AMP or TSH. The potency of DBc-AMP was approximately 50 times that of c-AMP on a basis of molarity. Like TSH, DBc-AMP increased the proportion of iodothyronines in the system as a whole, whereas c-AMP had little effect. The possible explanations for this are discussed.

Enantiomeric Diglycerides as Stereospecific Probes in Triglyceride Synthesis In Vitro

1972 ◽  
Vol 50 (8) ◽  
pp. 881-887 ◽  
Author(s):  
P. J. A. O'Doherty ◽  
A. Kuksis ◽  
D. Buchnea
Keyword(s):  
Fatty Acids ◽  
Thin Layer ◽  
Positional Distribution ◽  
Argentation Thin Layer Chromatography ◽  
Glycerol Molecule ◽  
Direct Acylation ◽  
Triglyceride Biosynthesis ◽  
Layer Chromatography ◽  
Single Enzyme

The stereospecificity of diglyceride acyltransferase (EC 2.3.1.20) was studied in the microsomes of rat intestine and liver using enantiomeric diglycerides as acceptors of labeled fatty acids. The diglyceride mixtures were prepared by combining equal amounts of synthetic 1,2- and 2,3-diglycerides of different degrees of unsaturation. The labeled triglycerides formed were resolved by argentation thin-layer chromatography, whereupon the products from each enantiomeric diglyceride moved to a different spot on the thin-layer plate.It was shown that both 1,2- and 2,3-diglycerides were utilized for direct acylation to triglycerides by both tissues. The diglyceride acyltransferase, if a single enzyme, showed a definite preference for the acylation of the 1,2-diglycerides. The intestine esterified more of the 2,3-isomer than did the liver. The yields of triglyceride depended upon the nature of the fatty acids involved, and their positional distribution on the glycerol molecule. The new method of stereospecific assessment of triglyceride biosynthesis in vitro is applicable to preparations of other subcellular fractions and to other suitable combinations of fatty acid and diglyceride precursors.

Metabolism by Schistosoma mansoni of a new schistosomicide: 2-[(1-methylpropyl)amino]-1-octanethiosulphuric acid

Parasitology ◽  
1995 ◽  
Vol 111 (2) ◽  
pp. 177-185 ◽  
Author(s):  
M. L. O. Penido ◽  
D. L. Nelson ◽  
L. Q. Vieira ◽  
D. G. Watson ◽  
J. R. Kusel
Keyword(s):  
Oral Dose ◽  
Thin Layer ◽  
Schistosoma Mansoni ◽  
Mass Spectroscopy ◽  
Female Adult ◽  
Male And Female ◽  
New Class ◽  
Organic Extracts ◽  
Layer Chromatography

SUMMARYIn order to investigate the mode of action of a new class of schistosomicides, the N-alkylaminoalkanethiosulphuric acids, the ‘outer 35S] 2-[(1-methylpropyl)amino]-1-octanethiosulphuric acid was synthesized. Labelling studies of adult Schistosoma mansoni were performed in infected mice and in in vitro incubations. After a single oral dose of the drug to infected mice, 5 metabolites were detected by thin-layer chromatography in organic extracts of male and female adult schistosomes. In vitro studies showed that the same compounds were present in organic extracts obtained from adult male and female worms. One of these metabolites was identified by mass spectroscopy as being the dimeric disulphide derivative of the parent labelled thiosulphuric acid.

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