Linked Life Data

2431157

Source:http://linkedlifedata.com/resource/pubmed/id/2431157

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1987-1-22
pubmed:abstractText
The surface charge of Toxoplasma gondii tachyzoites was evaluated by means of binding of colloidal iron hydroxide particles at pH 1.8, cationized ferritin particles at pH 7.2 and ruthenium red to the cell surface, as visualized by electron microscopy and by direct measurements of the electrophoretic mobility (EPM) of the cells suspended in solutions of different ionic strength and pH. At pH 7.2, T. gondii has a negative surface charge with a mean EPM of--1.1272 +/- 0.0917 micron.s-1 X V-1 X cm. No significant difference was observed between the EPM of living cells at 25 degrees C and that of glutaraldehyde-fixed cells. At lower pH, there is a decrease in the negative surface charge, with an isoelectric point at pH 3.5. At higher pH (greater than 10), there is an increase in the surface charge reaching an EPM of--1.5675 +/- 0.0848 micron.s-1 X V-1 X cm at pH 7.2. These results indicate that the surface of T. gondii contains both negatively and positively charged dissociating groups. Binding of cationized ferritin particles and ruthenium red throughout the cell surface of glutaraldehyde-fixed cells was observed. However, when living parasites were incubated at 4 degrees C in the presence of cationized ferritin some cells showed a uniform distribution of the label, others showed a patch-distribution and still in others no label was seen, indicating a process of mobility and shedding of surface anionic sites. Colloidal iron hydroxyde particles did not bind to the surface of T. gondii. Incubation of the parasites in the presence of neuraminidase from Clostridium perfringens or Vibrio cholerae or in the presence of proteolytic enzymes (trypsin or protease) did not interfere with the surface charge.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-4782
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
773-81
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
The surface charge of Toxoplasma gondii: a cytochemical and electrophoretic study.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't