scholarly journals Cyclopiazonic Acid Biosynthesis inAspergillussp.: Characterization of a Reductase-like R* Domain in Cyclopiazonate Synthetase That Forms and Releasescyclo-Acetoacetyl-l-tryptophan

Biochemistry ◽  
2009 ◽  
Vol 48 (36) ◽  
pp. 8746-8757 ◽  
Author(s):  
Xinyu Liu ◽  
Christopher T. Walsh
Keyword(s):  
Cyclopiazonic Acid ◽  
Acid Biosynthesis ◽  
R Domain

Identification and characterization of a locus putatively involved in colanic acid biosynthesis in Vibrio alginolyticus ZJ-51

Biofouling ◽  
2017 ◽  
Vol 34 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Xiaochun Huang ◽  
Chang Chen ◽  
Chunhua Ren ◽  
Yingying Li ◽  
Yiqin Deng ◽  
...  
Keyword(s):  
Vibrio Alginolyticus ◽  
Acid Biosynthesis ◽  
Colanic Acid ◽  
Identification And Characterization

scholarly journals Characterization of norepinephrine-evoked inward currents in interstitial cells isolated from the rabbit urethra

2002 ◽  
Vol 283 (3) ◽  
pp. C885-C894 ◽  
Author(s):  
G. P. Sergeant ◽  
K. D. Thornbury ◽  
N. G. McHale ◽  
M. A. Hollywood
Keyword(s):  
Reversal Potential ◽  
Cyclopiazonic Acid ◽  
Interstitial Cells ◽  
Equilibrium Potential ◽  
Inward Currents ◽  
Rabbit Urethra ◽  
Patch Technique ◽  
Dependent Mechanism ◽  
Stimulation Of

Freshly dispersed interstitial cells from the rabbit urethra were studied by using the perforated-patch technique. When cells were voltage clamped at −60 mV and exposed to 10 μM norepinephrine (NE) at 80-s intervals, either large single inward currents or a series of oscillatory inward currents of diminishing amplitude were evoked. These currents were blocked by either phentolamine (1 μM) or prazosin (1 μM), suggesting that the effects of NE were mediated via α1-adrenoceptors. NE-evoked currents were depressed by the blockers of Ca2+-activated Cl− currents, niflumic acid (10 μM), and 9-anthracenecarboxylic acid (9-AC, 1 mM). The reversal potential of the above currents changed in a predictable manner when the Cl− equilibrium potential was altered, again suggesting that they were due to activation of a Cl−conductance. NE-evoked currents were decreased by 10 μM cyclopiazonic acid, suggesting that they were dependent on store-released Ca2+. Inhibition of NE-evoked currents by the phospholipase C inhibitor 2-nitro-4-carboxyphenyl- N, N-diphenylcarbamate (100 μM) suggested that NE releases Ca2+ via an inositol 1,4,5-trisphosphate (IP3)-dependent mechanism. These results support the idea that stimulation of α1-adrenoceptors releases Ca2+ from an IP3-sensitive store, which in turn activates Ca2+-activated Cl− current in freshly dispersed interstitial cells of the rabbit urethra. This elevates slow wave frequency in these cells and may underlie the mechanism responsible for increased urethral tone during nerve stimulation.

scholarly journals Characterization of Ligand Binding to the Bifunctional Key Enzyme in the Sialic Acid Biosynthesis by NMR

2004 ◽  
Vol 279 (53) ◽  
pp. 55722-55727 ◽  
Author(s):  
Andrew J. Benie ◽  
Astrid Blume ◽  
Richard R. Schmidt ◽  
Werner Reutter ◽  
Stephan Hinderlich ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Ligand Binding ◽  
Acid Biosynthesis ◽  
Key Enzyme

scholarly journals Isolation and Characterization of FecA- and FeoB-Mediated Iron Acquisition Systems of the Spirochete Leptospira biflexa by Random Insertional Mutagenesis

2005 ◽  
Vol 187 (9) ◽  
pp. 3249-3254 ◽  
Author(s):  
Hélène Louvel ◽  
Isabelle Saint Girons ◽  
Mathieu Picardeau
Keyword(s):  
Insertional Mutagenesis ◽  
Iron Acquisition ◽  
Transposon Mutagenesis ◽  
Ecological Niches ◽  
Acid Biosynthesis ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Transposon Mutants

ABSTRACT The specific mechanisms by which Leptospira spp. acquire iron from their ecological niches are unknown. A major factor contributing to our ignorance of spirochetal biology is the lack of methods for genetic analysis of these organisms. In this study, we have developed a system for random transposon mutagenesis of Leptospira biflexa using a mariner transposon, Himar1. To demonstrate the validity of Himar1 in vivo transposon mutagenesis in L. biflexa, a screen of mutants for clones impaired in amino acid biosynthesis was first performed, enabling the identification of tryptophan and glutamate auxotrophs. To investigate iron transporters, 2,000 L. biflexa transposon mutants were screened onto media with and without hemin, thus allowing the identification of five hemin-requiring mutants, and the putative genes responsible for this phenotype were identified. Three mutants had distinct insertions in a gene encoding a protein which shares homology with the TonB-dependent receptor FecA, involved in ferric citrate transport. We also identified two mutants with a Himar1 insertion into a feoB-like gene, the product of which is required for ferrous iron uptake in many bacterial organisms. Interestingly, the growth inhibition exhibited by the fecA and feoB mutants was relieved by deferoxamine, suggesting the presence of a ferric hydroxamate transporter. These results confirm the importance of iron for the growth of Leptospira and its ability to use multiple iron sources.

Sign in / Sign up

Export Citation Format

Share Document