scholarly journals Sterol Side Chain Reductase 2 Is a Key Enzyme in the Biosynthesis of Cholesterol, the Common Precursor of Toxic Steroidal Glycoalkaloids in Potato

2014 ◽  
Vol 26 (9) ◽  
pp. 3763-3774 ◽  
Author(s):  
S. Sawai ◽  
K. Ohyama ◽  
S. Yasumoto ◽  
H. Seki ◽  
T. Sakuma ◽  
...  
Keyword(s):  
Side Chain ◽  
Common Precursor ◽  
Key Enzyme ◽  
The Common

scholarly journals cDNA sequence of human β-preprotachykinin, the common precursor to substance P and neurokinin A

FEBS Letters ◽  
1986 ◽  
Vol 208 (1) ◽  
pp. 67-72 ◽  
Author(s):  
A.J. Harmar ◽  
A. Armstrong ◽  
J.C. Pascall ◽  
K. Chapman ◽  
R. Rosie ◽  
...  
Keyword(s):  
Substance P ◽  
Cdna Sequence ◽  
Neurokinin A ◽  
Common Precursor ◽  
The Common

Reply to D. C. Mirhady: Torture and rhetoric in Athens

1996 ◽  
Vol 116 ◽  
pp. 132-134 ◽  
Author(s):  
Gerhard Thür
Keyword(s):  
Recent Article ◽  
Procedural Law ◽  
Strong Point ◽  
Common Precursor ◽  
Oral Testimony ◽  
Specialist Knowledge ◽  
The Common

The strong point of D. Mirhady's work (hereafter ‘M.’) lies in his interpretation of the rhetorical handbooks (technai). I agree in general with Part III, though admitting my lack of specialist knowledge in this field. To a large extent Part III confirms my observations on procedural law published in 1977 (Beweisführung, quoted supra n. 4). I approve of the opinion that, despite the use of written rather than oral testimony, the formulas, by which the evidence was used, did not change (M. after n. 62, see my recent article in: Die athenische Demokratie, ed. W. Eder [Stuttgart 1995], p. 329 f.). M. states an appealing hypothesis, that the introduction of written testimony did not so much change the procedure as provide the cause for a new handbook on rhetoric to be written, which he suggests was the common precursor to Aristotle and Anaximenes.

scholarly journals d-Sedoheptulose-7-phosphate is a common precursor for the heptoses of septacidin and hygromycin B

2018 ◽  
Vol 115 (11) ◽  
pp. 2818-2823 ◽  
Author(s):  
Wei Tang ◽  
Zhengyan Guo ◽  
Zhenju Cao ◽  
Min Wang ◽  
Pengwei Li ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Carbon Chain ◽  
Side Chain ◽  
Hygromycin B ◽  
Nucleoside Antibiotics ◽  
Common Precursor ◽  
Encoding Genes ◽  
Poultry Farming

Seven-carbon-chain–containing sugars exist in several groups of important bacterial natural products. Septacidin represents a group of l-heptopyranoses containing nucleoside antibiotics with antitumor, antifungal, and pain-relief activities. Hygromycin B, an aminoglycoside anthelmintic agent used in swine and poultry farming, represents a group of d-heptopyranoses–containing antibiotics. To date, very little is known about the biosynthesis of these compounds. Here we sequenced the genome of the septacidin producer and identified the septacidin gene cluster by heterologous expression. After determining the boundaries of the septacidin gene cluster, we studied septacidin biosynthesis by in vivo and in vitro experiments and discovered that SepB, SepL, and SepC can convert d-sedoheptulose-7-phosphate (S-7-P) to ADP-l-glycero-β-d-manno-heptose, exemplifying the involvement of ADP-sugar in microbial natural product biosynthesis. Interestingly, septacidin, a secondary metabolite from a gram-positive bacterium, shares the same ADP-heptose biosynthesis pathway with the gram-negative bacterium LPS. In addition, two acyltransferase-encoding genes sepD and sepH, were proposed to be involved in septacidin side-chain formation according to the intermediates accumulated in their mutants. In hygromycin B biosynthesis, an isomerase HygP can recognize S-7-P and convert it to ADP-d-glycero-β-d-altro-heptose together with GmhA and HldE, two enzymes from the Escherichia coli LPS heptose biosynthetic pathway, suggesting that the d-heptopyranose moiety of hygromycin B is also derived from S-7-P. Unlike the other S-7-P isomerases, HygP catalyzes consecutive isomerizations and controls the stereochemistry of both C2 and C3 positions.

Enhancement of pheomelanogenesis by L-dopa in the mouse melanocyte cell line, TM10, in vitro

1987 ◽  
Vol 87 (4) ◽  
pp. 507-512
Author(s):  
C. Sato ◽  
S. Ito ◽  
T. Takeuchi
Keyword(s):  
Cell Line ◽  
Growth Medium ◽  
Yellow Pigment ◽  
Black Pigment ◽  
Established Cell Line ◽  
Treatment Results ◽  
Common Precursor ◽  
Established Cell ◽  
The Common

Cells of TM10, an established cell line, are melanocytes that contain equal amounts of eumelanin (black pigment) and pheomelanin (yellow pigment). The content of pheomelanin drastically increased when the cells were cultured in growth medium containing 0.2mM-L-dopa (L-dihydroxyphenylalanine), which is the common precursor for both eumelanogenesis and pheomelanogenesis. After this treatment, the amount of pheomelanin was 3.7-fold greater than that of control in TM10, whereas the amount of eumelanin changed very little. In contrast, 5-S-cysteinyl-dopa, which is the specific precursor for pheomelanogenesis downstream of L-dopa, did not cause preferential increase in pheomelanogenesis. Ultrastructural observations also confirmed these results; in 0.2mM-L-dopa, an increase in the number of pheomelanosomes was observed in the cytoplasm of TM10 cells. Our results also suggest that the L-dopa treatment results in a decrease in tyrosinase activity per melanosome.

scholarly journals Plakinamine P, A Steroidal Alkaloid with Bactericidal Activity against Mycobacterium tuberculosis

Marine Drugs ◽  
2019 ◽  
Vol 17 (12) ◽  
pp. 707 ◽  
Author(s):  
Carolina Rodrigues Felix ◽  
Jill C. Roberts ◽  
Priscilla L. Winder ◽  
Rashmi Gupta ◽  
M. Cristina Diaz ◽  
...  
Keyword(s):  
Axial Position ◽  
Side Chain ◽  
Moderate Activity ◽  
Steroidal Alkaloid ◽  
Magnetic Resonance Data ◽  
Resonance Data ◽  
Low Toxicity ◽  
The Common ◽  
Future Work ◽  
Discovery Pipeline

Tuberculosis is the leading cause of death due to infectious disease worldwide. There is an urgent need for more effective compounds against this pathogen to control the disease. Investigation of the anti-mycobacterial activity of a deep-water sponge of the genus Plakina revealed the presence of a new steroidal alkaloid of the plakinamine class, which we have given the common name plakinamine P. Its structure is most similar to plakinamine L, which also has an acyclic side chain. Careful dissection of the nuclear magnetic resonance data, collected in multiple solvents, suggests that the dimethyl amino group at the 3 position is in an equatorial rather than axial position unlike previously reported plakinamines. Plakinamine P was bactericidal against M. tuberculosis, and exhibited moderate activity against other mycobacterial pathogens, such as M. abscessus and M. avium. Furthermore, it had low toxicity against J774 macrophages, yielding a selectivity index (SI, or IC50/MIC) of 8.4. In conclusion, this work provides a promising scaffold to the tuberculosis drug discovery pipeline. Future work to determine the molecular target of this compound may reveal a pathway essential for M. tuberculosis survival during infection.

scholarly journals Evidence for N-linked glycosylation in Toxoplasma gondii

1993 ◽  
Vol 291 (3) ◽  
pp. 713-721 ◽  
Author(s):  
M Odenthal-Schnittler ◽  
S Tomavo ◽  
D Becker ◽  
J F Dubremetz ◽  
R T Schwarz
Keyword(s):  
Toxoplasma Gondii ◽  
Gel Filtration ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Surface Glycoprotein ◽  
Common Precursor ◽  
The Common ◽  
Oligosaccharide Structures

In this paper we report experiments demonstrating the presence of N-linked oligosaccharide structures in Toxoplasma gondii tachyzoites, providing the first direct biochemical evidence that this sporozoan parasite is capable of synthesizing N-linked glycans. The tachyzoite surface glycoprotein gp23 was metabolically labelled with [3H]glucosamine and [3H]mannose. Gel-filtration chromatography on Bio-Gel P4 columns produced four radiolabelled N-linked glycopeptides which were sensitive to peptidase-N-glycanase F, but resistant to endoglycosidases H and F. Using chemical analysis and exoglycosidase digestions followed by Dionex-high-pH anion-exchange chromatography and size fractionation on Bio-Gel P4 we show that gp23 has N-linked glycans in the hybrid- or complex-type structure composed of N-acetylgalactosamine, N-acetylglucosamine and mannose and devoid of sialic acid and fucose residues. In addition, the sensitivity of glycopeptides from glycoprotein extracts to endoglycosidases H and F revealed the in vivo synthesis of oligomannose-type structures by T. gondii tachyzoites. We have extended these findings by demonstrating the ability of T. gondii microsomes to synthesize in vitro a glucosylated lipid-bound high-mannose structure (Glc3Man9GlcNAc2) that is assumed to be identical with the common precursor for N-glycosylation in eukaryotes.

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