Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.3 (phospholipase C)
 18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To obtain high yields of extracellular enzymes and toxins for immunological analysis, type culture collection strains of Clostridium perfringens types A to D and 28 fresh isolates of C. perfringens type A from humans were grown in fermenters under controlled conditions in a pre-reduced proteose peptone medium. The type culture collection strains all showed different characteristics with respect to growth rates and pH optima for growth. Production of phospholipase C (alpha-toxin), haemolysin and lethal activity varied considerably between the different types. Growth and extracellular protein production in fermenters with pH control and static or stirred cultures were compared. Production of all extracellular proteins measured was markedly improved by cultivation in fermenters with pH control. Strain ATCC13124 produced five times more phospholipase C than any of 28 freshly isolated strains of C. perfringens type A, grown under identical conditions. Haemolytic and lethal activities of the ATCC strain were equal or superior to the activities of any of the freshly isolated strains. There were no differences in the bacterial yields and in the production of extracellular toxins between type A strains isolated from clinical cases of gas gangrene and abdominal wounds, and those isolated from faecal samples from healthy persons.
J Gen Microbiol 1976 Sep
PMID:Production of phospholipase C (alpha-toxin), haemolysins and lethal toxins by Clostridium perfringens types A to D. 1 Mar 44

The haemagglutinating ability of three strains of IBV was investigated. It was shown that whereas strain Beaudette had no detectable haemagglutinin, both Connecticut and Massachusetts agglutinated red cells of various species. The haemagglutinin of Connecticut was detectable after sucrose gradient purification whereas that of Massachusetts required both the purification step and incubation with the enzyme phospholipase C to reveal it. The agglutination could be inhibited by specific antisera. Some studies on the nature of the red cell receptor, and the possible presence of a receptor destroying enzyme, are reported.
J Gen Virol 1975 Sep
PMID:Haemagglutination by avian infectious bronchitis virus-a coronavirus. 17 Mar 78

Immunosorbents were derived from avid and non-avid sera raised in rabbits to multiple or single injections of chlamydiae passaged once or three times in HeLa cells after routine passage in eggs. Egg-derived suspensions of chlamydiae required pretreatment before application to immunosorbent columns; this was most conveniently done by fractionation on Sepharose 4B. Immunosorbents derived from avid serum had greater capacity than those from non-avid sera. However, organisms were desorbed in low yield from an avid immunosorbent, but in higher yields from non-avid immunosorbents. Even under the best conditions, the immunosorbents yielded suspensions of organisms still contaminated with egg antigens. Partially purified suspensions of chlamydiae were also treated with phospholipase C to yield suspensions of high purity.
J Gen Microbiol 1975 Jul
PMID:Studies on the purification of chlamydial agents grown in yolk sacs of embryonated eggs using disulphide-linked immunosorbents and enzymes. 23 96

Egg-grown chlamydiae (EGO) have a yolk sac antigen assoicated with their surface which is absent from cell monolayer-grown organisms (CGO). EGO infectivity was specifically neutralized by rabbit antiserum to normal yolk sac; CGO infectivity, before or after incubation with normal yolk sac material, was not neutralized. Treatment of EGO with Clostridium welchii culture filtrate, containing phospholipase C, abolished spontaneous infectivity for monolayers and neutralization by anti-yolk sac antiserum but did not affect centrifuge-assisted infectivity. The possible significance of host antigen on the chlamydial surface is considered.
J Gen Microbiol 1979 May
PMID:Host modification of chlamydiae: presence of an egg antigen on the surface of chlamydiae grown in the chick embryo. 38 99

The progress of secretion of alpha-toxin and total extracellular protein by Staphylococcus aureus (Wood 46), grown aerobically at 37 degrees C, in a 3% (s/v) tryptone soya broth medium supplemented with vitamins was followed. Exoprotein was secreted at a high rate by intact bacteria during the exponential phase (to 9 h) and into the post-exponential phase. After 18 h, when exoprotein accounted for 33% of the total protein in the culture, no further exoprotein was secreted although the bacterial density continued to increase at a low rate beyond this time. During the phase of active secretion, alpha-toxin represented a constant proportion of total exoprotein, the differential rate of synthesis of which increased by a factor of four after the end of exponential growth. Concomitant with the increase in the differential rate of exoprotein formation there was a fourfold increase in the intracellular concentration of RNA precursor material.
J Gen Microbiol 1977 Apr
PMID:The characteristics of extracellular protein secretion by Staphylococcus aureus (Wood 46) and their relationship to the regulation of alpha-toxin formation. 87 52

When solutions containing agonists are applied to the innervated face of an Electrophorus electroplaque, the membrane's conductance increases. The agonist-induced conductance is increased at more negative membrane potentials. The "instantaneous" current-voltage curve for agonist-induced currents is linear and shows a reversal potential near zero mV; chord conductances, calculated on the basis of this reversal potential, change epsilon-fold for every 62-mV change in potential when the conductance is small. Conductance depends non-linearly on small agonist concentrations; at all potentials, the dose-response curve has a Hill coefficient of 1.45 for decamethonium (Deca) and 1.90 for carbamylcholine (Carb). With agonist concentrations greater than 10(-4) M Carb or 10(-%) M Deca, the conductance rises to a peak 0.5-1.5 min after introduction of agonist, then declines with time; this effect resembles the "desensitization" reported for myoneural junctions. Elapid alpha-toxin, tubocurarine, and desensitization reduce the conductance without changing the effects of potential; the apparent dissociation constant for tubocurarine is 2 X 10(-7) M. By contrast, procaine effects a greater fractional inhibition of the conductance at high negative potentials.
J Gen Physiol 1975 Jun
PMID:Conductance increases produced by bath application of cholinergic agonists to Electrophorus electroplaques. 119 85

Hormonal modulation of neurotransmission emerged as a concept from the recognition that adrenocortical steroids exert profound effects at the level of receptors, G-proteins and effector units. G-proteins, a family of guanine nucleotide binding regulatory components that couple neurotransmitter receptors to various types of intracellular effector systems, appear to be a key target of glucocorticoid (GC) action in the CNS. It is thought that Gs/Gi mediates stimulation/inhibition of adenylate cyclase (AC system), which forms cyclic AMP as second messenger, while receptors stimulating phospholipase C do so through Go to produce two second messengers, inositol 1,4,5-triphosphate and diacylglycerol (PI system). Recent evidence suggests that GC increase Gs alpha-and decrease Gi alpha-protein subunit expression without affecting Go alpha. Activation of central pre- and postsynaptic 5-HT1A receptors which are linked to the Gi-AC complex, induces hypothermia and ACTH/cortisol release in rodents and humans. Compared with controls, patients with a major depressive disorder exhibit increased basal cortisol secretion associated with decreased hypothermic and ACTH/cortisol responses. The attenuated neuroendocrine and thermoregulatory response to 5-HT1A receptor activation may reflect a GC-dependent feedback inhibition of the hypothalamic-pituitary-adrenal (HPA) system and subsensitivity of the presynaptic 5-HT1A-Gi-AC complex function. Differential regulation of 5-HT1A and 5-HT2 function leading to a relative 5-HT2-Go-PI complex supersensitivity may maintain HPA hyperactivity during the course of depression. These findings corroborate recent reports that GC, via GC-GC receptor (GR) complex activated promotion of gene transcription, modify the expression 5-HT1A-coupled Gi (but not 5-HT2-coupled Go) resulting in altered sensitivity of 5-HT1A-mediated signal transduction and further support the hypothesis of a differential regulation of 5-HT1A and 5-HT2 receptor function and a GC-GR/5-HT1A-G-protein--effector system-related abnormality in depression.
J Neural Transm Gen Sect 1991
PMID:The 5-HT receptor--G-protein--effector system complex in depression. I. Effect of glucocorticoids. 164 69

The short-time depolarization effects on the integral conductance induced by S. aureus alpha-toxin (ST) in planar lipid bilayer membranes has been studied. Ion channels formed by ST were found to have several potential-induced nonconductance (closed) states. The transitions of ion channels between the states are only through one conductance state. The transition of ST-channels from closed to open state is induced by membrane depolarization. The amplitude current after a series of voltage pulses is a function of pulse number, and is effectively independent of the time interval between the neighbouring pulses. Therefore, a membrane which contains a pool of ion channels "remembers" its previous existence. A simple model can be used to explain this phenomenon.
Gen Physiol Biophys 1990 Dec
PMID:Memory is a property of an ion channels pool: ion channels formed by Staphylococcus aureus alpha-toxin. 170 76

The simple method is proposed for isolation and purification of staphylococcal alpha-toxin that permits one to obtain the homogeneous toxic protein with high activity. The time necessary for maximal toxin production at cultivation has been defined. The thermostability and interferonogenic characteristics of the obtained alpha-toxin were studied.
Mol Gen Mikrobiol Virusol 1991 Sep
PMID:[A simple method of purifying staphylococcal alpha-toxin and a study of its properties]. 174 73

The relative chromosomal locations of 20 virulence-associated genes in four clinical isolates of Pseudomonas aeruginosa were investigated by using transverse alternating-field electrophoresis. Each strain had a characteristic restriction pattern when digested with either SpeI or DraI and electrophoresed with 15-s pulses. All four strains had restriction fragments that hybridized with each of the gene probes used, although there were variations in fragment size. An SpeI physical map constructed by Ratnaningsih et al. (E. Ratnaningsih, S. Dharmsthiti, V. Krishnapillai, A. Morgan, M. Sinclair, and B. W. Holloway, J. Gen. Microbiol. 136:2351-2357, 1990) for one of these strains, PAO1, was used to identify the location of 11 previously unmapped genes. The physical locations of the remaining genes were found to be consistent with their genetically mapped loci. Whereas phospholipase C and alginate structural and regulatory genes were associated in three separate clusters in the early, middle, and late regions of the chromosome, no virulence cluster was identified. Our data suggest that the pathogenicity of P. aeruginosa results from the gradual acquisition of genes encoding various virulence determinants.
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PMID:Physical mapping of virulence-associated genes in Pseudomonas aeruginosa by transverse alternating-field electrophoresis. 191 8


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