Linked Life Data

836844

Source:http://linkedlifedata.com/resource/pubmed/id/836844

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1977-4-15
pubmed:abstractText
Extraction with 0.1 M NaCl in 0.01 M Tris-HCl buffer, pH 8.0 releases from liver nuclei 30-40-S ribonucleoprotein particles containing newly synthesized RNA. Separation of the protein moiety of these particles by acid-urea gel electrophoresis depends on the concentration of beta-mercaptoethanol in the buffer used for the solubilization of the particles. At low concentration or with short time of solubilization, only a polypeptide chain with apparent molecular weight 38 000 penetrates into the gel and can be detected by electrophoresis. By introduction of two-dimensional polyacrylamine gel electrophoresis, we succeeded to separate the protein moiety of these particles into a core group of 4 major and 6 minor polypeptides with molecular weights ranging from 38 000 to 50 000 and a second group of 19 polypeptides ranging in molecular weight from 50 000 to 120 000. The composition of the protein moiety of these particles is dependent on the extent of purification. Polypeptides with molecular weight below 50 000 represent 55% of the total protein of particles purified only by centrifugation through a 15-30% sucrose gradient. If the particles were first purified by gel filtration through Bio-Gel A-50m followed by centrifugation in sucrose gradient, the low molecular weight proteins represent 80% of all the proteins of the particles. The purification removed selectively the minor high molecular weight polypeptides without resulting in any extensive release of the four major polypeptides with molecular weight below 50 000 which form a stable core particle. By repeated purification it is possible to strip the particles of the high molecular weight polypeptides even further. An increase in the NaCl concentration of the extraction buffer to 0.35 M will extract additional 30-40-S particles associated with a newly synthesized RNA from the cell nucleus. These particles contain the same polypeptides as particles extracted at lower salt concentration. Extraction with 0.1 M and 0.35 M NaCl at pH 8.0 removed from the nucleus approximately 55% of all RNA labeled in 30 min after intraperitoneal injection of [3H] orotic acid to the rats.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
474
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
524-35
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Dependence of the composition of the protein moiety of nuclear ribonucleoprotein particles on the extent of particle purification as studied by electrophoresis including a two-dimensional procedure.
pubmed:publicationType
Journal Article