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Biomedical subjects

S Capitani

Publications and source records attributed to S Capitani.

At least 181 records · Page 10Linked to original sources
PubMed1981

Effect of phospholipid vesicles on endogenous RNA polymerase activity of isolated rat liver nuclei.

Negatively charged phosphatidylserine vesicles increase RNA polymerase activity of isolated rat liver nuclei, whereas inhibition is obtained with sphingomyelin, phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol vesicles. The effect of phosphatidylserine on template activity is dose-dependent and similar to that reported for acidic polymers like heparin. These data indicate that the nature of the polar head is mainly responsible for the different effects and suggest that the phospholipids may be involved in mediating gene expression.

Animals↗
PubMed1979

Effect of phosphatidylcholine vesicles on the activity of DNA polymerase-alpha.

Phosphatidylcholine vesicles stimulate the activity of the DNA polymerase-alpha from calf thymus. This effect is dependent upon the way of addition to the Mg ions, and the extent of the 3H-dTTP incorporation is closely related to the concentration of the vesicles. A role of phospholipids on the activity of the DNA-related enzymes is suggested.

Animals↗
PubMed1978

H2B nucleohistone-phospholipid interactions. Thermal denaturation and ultrastructural analysis.

Sphingomyelin, phosphatidylserine, bovine lecithin and phosphatidylethanolamine modify the thermal stabilization of H2B-DNA complexes, by inducing stabilization at 0.3 and 0.6 H2B : DNA weight ratios and destabilify the arrangement of nucleohistone is confirmed by ultrastructural analysis which indicates a competitive action of these molecules during the nucleoprotein assembly. A possible regulatory role of phospholipids on native chromatin is proposed.

Chromatin↗
PubMed1977

Chromatin phospholipids in normal and chronic lymphocytic leukemia lymphocytes.

Certain phospholipids are associated with the nonhistone chromosomal proteins extracted from normal B- and chronic lymphocytic leukemia lymphocytes. The ratio of phospholipids to nonhistone chromosomal proteins was constant with the different methods used for isolating nuclei and extracting the chromatin, although the various methods allowed a different recovery of total lipids from chromatin. Three phospholipids were extractable from the nonhistone protein fraction, but their respective ratios varied in chronic lymphocytic leukemia compared to normal B-lymphocytes. The most significant variation concerns the reduction of sphingomyelin content in leukemic lymphocytes, since this prospholipid in vitro affects both DNA stability and transcription.

B-Lymphocytes↗
PubMed1976

Lipid-F1 nucleohistone interactions.

High concentrations of phospholipids determine destabilization of F1 histone-DNA complex at the weight ratios, histone:DNA, 0.8:1 and 1:1, but low concentrations cause only negligible destabilization. Cholesterol at high weight ratios has little effect on nucleohistone stability. Only linolenic acid of the fatty acids used reproduces similar changes in the thermal stability of F1 histone-DNA complex as phospholipids. The type of interaction of phospholipids with the F1 histone-DNA complex is analyzed, and the involvement of phospholipids in DNA replication in vivo is discussed.

Binding Sites↗
PubMed1976

Chromosomal proteins in human B and T lymphocytes.

Histones and non-histone chromosomal proteins were characterized in B and T human lymphocytes by means of polyacrylamide disc gel electrophoresis. It was found that while histones do not present appreciable differences in the two examined populations, non-histone chromosomal proteins exhibit distinct electrophoretic profiles. Low molecular weight proteins predominate in B lymphocytes whereas high and intermediate proteins are largely represented in T lymphocytes. The latter proteins may be related to the capability of these resting cells to proliferate under appropriate antigenic stimuli.

B-Lymphocytes↗