ChemInform Abstract: A Chromogenic Substrate for the Continuous Assay of Mammalian Phosphoinositide-Specific Phospholipase C.

ChemInform ◽  
2010 ◽  
Vol 28 (39) ◽  
pp. no-no
Author(s):  
A. V. RUKAVISHNIKOV ◽  
M. RYAN ◽  
O. H. GRIFFITH ◽  
J. F. W. KEANA
Keyword(s):  
Phospholipase C ◽  
Chromogenic Substrate ◽  
Continuous Assay

A CHROMOGENIC SUBSTRATE FOR THE CONTINUOUS ASSAY OF MAMMALIAN PHOSPHOINOSITIDE-SPECIFIC PHOSPHOLIPASE C

1997 ◽  
Vol 7 (10) ◽  
pp. 1239-1242 ◽  
Author(s):  
Aleksey V Rukavishnikov ◽  
Margret Ryan ◽  
O.Hayes Griffith ◽  
John F.W Keana
Keyword(s):  
Phospholipase C ◽  
Chromogenic Substrate ◽  
Continuous Assay

A chromogenic substrate for phosphatidylinositol-specific phospholipase C: 4-nitrophenyl myo-inositol-1-phosphate

1991 ◽  
Vol 60 (2) ◽  
pp. 101-110 ◽  
Author(s):  
M.S. Shashidhar ◽  
Johannes J. Volwerk ◽  
O. Hayes Griffith ◽  
John F.W. Keana
Keyword(s):  
Phospholipase C ◽  
Chromogenic Substrate ◽  
Inositol 1

ChemInform Abstract: Synthesis of a New Fluorogenic Substrate for the Continuous Assay of Mammalian Phosphoinositide-Specific Phospholipase C.

ChemInform ◽  
2010 ◽  
Vol 30 (33) ◽  
pp. no-no
Author(s):  
Aleksey V. Rukavishnikov ◽  
Tatiana O. Zaikova ◽  
G. Bruce Birrell ◽  
John F. W. Keana ◽  
O. Hyes Griffith
Keyword(s):  
Phospholipase C ◽  
Fluorogenic Substrate ◽  
Continuous Assay

Synthesis of a new fluorogenic substrate for the continuous assay of mammalian phosphoinositide-specific phospholipase C

1999 ◽  
Vol 9 (8) ◽  
pp. 1133-1136 ◽  
Author(s):  
Aleksey V. Rukavishnikov ◽  
Tatiana O. Zaikova ◽  
G.Bruce Birrell ◽  
John F.W. Keana ◽  
O. Hayes Griffith
Keyword(s):  
Phospholipase C ◽  
Fluorogenic Substrate ◽  
Continuous Assay

scholarly journals Kinetic mechanism of Clostridium perfringens phospholipase C. Hydrolysis of a thiophosphate analogue of lysophosphatidylcholine

1991 ◽  
Vol 280 (2) ◽  
pp. 407-410 ◽  
Author(s):  
P R Young ◽  
W R Snyder ◽  
R F McMahon
Keyword(s):  
Phospholipase C ◽  
Clostridium Perfringens ◽  
Kinetic Mechanism ◽  
Compound I ◽  
Nitrobenzoic Acid ◽  
Competitive Mechanism ◽  
Simple Slope ◽  
Continuous Assay ◽  
Hydrolysis Of

The hydrolysis of S-[2-(hexadecanoyloxy)ethyl]thiophosphocholine (I), an analogue of lysophosphatidylcholine, by Clostridium perfringens phospholipase C, was followed at pH 7.5, 37 degrees C and I 1.0 (maintained with KCl), in a continuous assay, by monitoring the reduction of 5,5′-dithiobis-(2-nitrobenzoic acid) at 412 nm. Simple saturation kinetics are observed with linear mixed-type slope-intercept effects for the hydrolysis of compound (I) with variable [Ca2+] at fixed concentrations of compound (I) and a simple slope effect as [compound (I)] is varied at fixed concentrations of Ca2+. These data are consistent with a simple ordered rapid-equilibrium mechanism in which Ca2+ binds to the enzyme first followed by substrate. The observed kinetic constants at pH 7.5, 37 degrees C and I 1.0 are K1 = 12.0 mM (Ca2+ dissociation), K2 = 36 microM [compound (I) dissociation] and Vmax. = 552 microM.min-1.mg-1. Alkane diammonium salts inhibit the enzyme by a non-competitive mechanism that involves binding to free enzyme, E.Ca2+ and E.Ca2+.S. The use of the simple micellarized substrate under these conditions allows the determination of kinetic and inhibition constants without complications arising from enzyme-micelle interactions.

Evaluation and Interlaboratory Validation of a Selective Agar for Phosphatidylinositol-Specific Phospholipase C Activity Using a Chromogenic Substrate To Detect Listeria monocytogenes from Foods†

2003 ◽  
Vol 66 (3) ◽  
pp. 441-445 ◽  
Author(s):  
KAREN C. JINNEMAN ◽  
JAN M. HUNT ◽  
CHERYL A. EKLUND ◽  
JANE S. WERNBERG ◽  
PATRICIA N. SADO ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Phospholipase C ◽  
Environmental Samples ◽  
Direct Detection ◽  
Reference Method ◽  
Bacillus Species ◽  
Chromogenic Substrate ◽  
Listeria Species ◽  
Listeria Ivanovii ◽  
Interlaboratory Validation

Phosphatidylinositol-specific phospholipase C (PI-PLC) activity is a potential virulence factor and is exhibited only by the Listeria species Listeria monocytogenes and Listeria ivanovii. A chromogenic substrate for the direct detection of PI-PLC activity is available in a new medium (BCM L. monocytogenes plating agar). The use of a chromogenic substrate offers a mechanism with which to directly screen for L. monocytogenes and L. ivanovii other than the esculin used in Oxford (OXF) and Palcam (PAL) agars, which screen for all Listeria species. The specificity levels of BCM plating agar and of BCM confirmation and rhamnose agars were evaluated with 107 Listeria and 10 Bacillus species isolates. In addition, BCM L. monocytogenes plating agar was compared with standard Listeria selective agars (OXF and PAL agars) with regard to the recovery of L. monocytogenes from 2,000 food and environmental samples obtained from eight participating laboratories. A Listeria species was isolated from at least one of the agars in 209 analyses, and L. monocytogenes was isolated in 135 of these analyses. In 27 of the analyses in which L. monocytogenes was isolated, one or more of the selective differential agars used failed to isolate L. monocytogenes, and therefore the results of these analyses were discrepant. Relative to a reference method involving the use of all three agars (OXF, PAL, and BCM agars), the OXF-BCM, PAL-BCM, and OXF-PAL combinations had sensitivities of 99.3, 99.2, and 90.2%, respectively. In statistical analyses of the different combinations of agars, the OXF-BCM and BCM-PAL combinations were found to be superior to the OXF-PAL combination for the detection of L. monocytogenes.

Synthesis of Fluorogenic Substrates for Continuous Assay of Phosphatidylinositol-Specific Phospholipase C

2001 ◽  
Vol 12 (2) ◽  
pp. 307-313 ◽  
Author(s):  
Tatiana O. Zaikova ◽  
Aleksey V. Rukavishnikov ◽  
G. Bruce Birrell ◽  
O. Hayes Griffith ◽  
John F. W. Keana
Keyword(s):  
Phospholipase C ◽  
Fluorogenic Substrates ◽  
Continuous Assay

Inositol lipids and TRPC channel activation

2007 ◽  
Vol 74 ◽  
pp. 37-45 ◽  
Author(s):  
James W. Putney
Keyword(s):  
Plasma Membrane ◽  
Phospholipase C ◽  
Transient Receptor Potential ◽  
Calcium Signalling ◽  
Receptor Potential ◽  
Breakdown Product ◽  
Channel Activation ◽  
Inositol Lipids ◽  
Transient Receptor ◽  
Secondary Mechanism

The original hypothesis put forth by Bob Michell in his seminal 1975 review held that inositol lipid breakdown was involved in the activation of plasma membrane calcium channels or ‘gates’. Subsequently, it was demonstrated that while the interposition of inositol lipid breakdown upstream of calcium signalling was correct, it was predominantly the release of Ca2+ that was activated, through the formation of Ins(1,4,5)P3. Ca2+ entry across the plasma membrane involved a secondary mechanism signalled in an unknown manner by depletion of intracellular Ca2+ stores. In recent years, however, additional non-store-operated mechanisms for Ca2+ entry have emerged. In many instances, these pathways involve homologues of the Drosophila trp (transient receptor potential) gene. In mammalian systems there are seven members of the TRP superfamily, designated TRPC1–TRPC7, which appear to be reasonably close structural and functional homologues of Drosophila TRP. Although these channels can sometimes function as store-operated channels, in the majority of instances they function as channels more directly linked to phospholipase C activity. Three members of this family, TRPC3, 6 and 7, are activated by the phosphoinositide breakdown product, diacylglycerol. Two others, TRPC4 and 5, are also activated as a consequence of phospholipase C activity, although the precise substrate or product molecules involved are still unclear. Thus the TRPCs represent a family of ion channels that are directly activated by inositol lipid breakdown, confirming Bob Michell's original prediction 30 years ago.

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