We analyzed 11 H. pylori isolates from humans using the artificial chromogenic substrate paranitrophenylphosphorylcholine to detect phospholipase C (PLC) activity. The range of PLC in sonicates was 8.8-92.3 (Mean 56.9 +/- 6.5) nmol of substrate hydrolysed min-1 mg-1 protein; the amount of activity was not associated with urease or cytotoxin levels. Addition of sorbitol or glycerol enhanced PLC activity of H. pylori sonicate and purified PLC from C. perfringens (PLC1) but not purified PLC from B. cereus (PLC3). H. pylori sonicates had little acid phosphatase and no detectable alkaline phosphatase activity, and H. pylori PLC showed markedly different biochemical characteristics from either phosphatase. In total, these studies indicate that activity measured in H. pylori sonicate by PLC assay is due to PLC and not phosphatase activity. The temperature optimum for PLC activity of H. pylori sonicate was 56 degrees C and for PLC 1 was 65 degrees C. For H. pylori PLC and PLC1, optimal activity occurred at pH 8. Despite multiple similarities between H. pylori PLC and PLC1, known PLC inhibitors show different interactions with each enzyme. Although PLC activity is present in many subcellular constituents of H. pylori, including culture supernatants and water extracts, highest specific activity is associated with a membrane-enriched fraction.
Pharmacology, Toxicology and Pharmaceutical Science
1
10%
Biochemistry, Genetics and Molecular Biology
1
10%
Agricultural and Biological Sciences
1
10%
Computer Science
1
10%
Other
0
0%
Unknown
4
40%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 09 December 2003.
All research outputs
#12,425,541
of 34,517,289 outputs
Outputs from Zentralblatt für Bakteriologie international journal of medical microbiology
#76
of 225 outputs
Outputs of similar age
#11,451
of 29,026 outputs
Outputs of similar age from Zentralblatt für Bakteriologie international journal of medical microbiology
#6
of 10 outputs
Altmetric has tracked 34,517,289 research outputs across all sources so far. This one is in the 37th percentile – i.e., 37% of other outputs scored the same or lower than it.
So far Altmetric has tracked 225 research outputs from this source. They receive a mean Attention Score of 4.5. This one is in the 4th percentile – i.e., 4% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 29,026 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 7th percentile – i.e., 7% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 10 others from the same source and published within six weeks on either side of this one. This one has scored higher than 4 of them.
