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C Basilio

Publications and source records attributed to C Basilio.

9 recordsLinked to original sources
PubMed1990

Ethanol sulfation by the pulmonary ethanol metabolizing system (PET).

Rat lung slices incubated in a Krebs Ringer bicarbonate buffer metabolized ethanol by sulfocunjugation at a rate of about 500 mumoles/g x hr when the ethanol concentration was 11 mM. Tissue slices from dog and rabbit lung also were able to metabolize this alcohol showing similar time curves and rates. In all cases ethanol metabolism showed a dependence on the concentration of ethanol which is typical of allosteric enzymes. The calculated Hill coefficient was between 1.69 and 2.07 in the three species studied. Sulfoconjugation of ethanol by rat lung slices showed a Km for ethanol of 26.59 mM and a Vmax of 11,357 mumoles/g x hr. The Km for ethanol determined with dog lung slices was 20.93 mM and Vmax was 8,052 mumoles/g x hr. In the case of rabbit lung, Km for ethanol was 20.15 mM whereas Vmax was 17,379 mumoles/g x hr. Preliminary evidence would seem to indicate that the human lung is also able to metabolize ethanol by conjugation with sulfate. These results suggest that the lung is endowed with a remarkable potential to metabolize ethanol by sulfoconjugation. In vivo, however, sulfoconjugation may be limited by substrate availability.

Animals↗
PubMed1988

Proteolysis of mitochondrial-coded and nuclear-coded proteins found in yeast mitochondria.

The rate of degradation of radioactive labeled mitochondrial proteins synthesized both in vitro and in vivo by isolated yeast mitochondria and growing yeast cells respectively, has been studied. It was found that the in vitro-synthesized mitochondrial proteins are rapidly degraded by an energy-dependent proteolytic system. Under the same experimental conditions the in vivo-synthesized mitochondrial proteins are slowly degraded to a limited extent by a protease which is slightly inhibited by ATP. During this period, the mitochondria are coupled and metabolically active. It is proposed that mitochondria possess an energy-dependent proteolytic system that recognizes as substrates either "abnormal" proteins or unassembled protein subunits encoded in the mitochondrial genome. An apparently different system, which is independent of energy, seems to be responsible for the slow and limited degradation of "normal" mitochondrial proteins.

Adenosine Triphosphatases↗
PubMed1985

Effect of ethionine on the in vitro synthesis and degradation of mitochondrial translation products in yeast.

The effect of ethionine, an amino acid analog of methionine, has been studied in Saccharomyces cerevisiae in relation to cell growth, oxygen consumption, in vitro protein synthesis of mitochondrial translation products (MTPs) and the degradation of those mitoribosomally made proteins by an ATP-dependent process present within the organelle. Ethionine was found to increase the generation time of those cells already committed to cell division and to abolish the initiation of new cell cycles. Oxygen consumption of cultures grown in the presence of the analog was drastically reduced. Ethionine was also found to impair the incorporation of methionine and leucine into mitochondrial translation products, however the synthesis of proteins was not totally blocked and, apparently, mitochondria utilized ethionine as a precursor amino acid. MTPs synthesized by isolated mitochondria in the presence of ethionine were rapidly degraded inside the organelle at a faster rate compared with the normal proteins synthesized under identical conditions in the mitochondria. It is also shown that these in vitro synthesized proteins are degraded by an ATP-stimulated proteolytic system, as has been previously established.

Adenosine Triphosphate↗
PubMed1984

Further characterization of the pulmonary ethanol metabolizing system (PET).

A postmitochondrial preparation of rat lung homogenate was able to metabolize ethanol (205.8 mumoles/g X hr) only in the presence of uridine diphosphate glucuroniate, with a Km for ethanol of about 14 mM. Lung slices from the same animals incubated in a Krebs ringer bicarbonate buffer showed a biphasic time-curve for ethanol metabolism. The amount of metabolized ethanol first increased and then decreased. The metabolic product of this system (PET-I) was sensitive to the action of betaglucuronidase. Lung slices from some animals, however, showed a monophasic time-curve for ethanol metabolism. The metabolic product of this system (PET-II) was insensitive to the action of beta-glucuronidase but sensitive to that of sulfatase. These results confirm our previous suggestion that the lung of the rat is able to metabolize ethanol by a conjugation process catalyzed by a glucuronyl-transferase. In addition, the evidence obtained in this work also suggests that in some animals PET is represented by a sulfotransferase.

Animals↗
PubMedDate not supplied

Enzymatic lysis of sulfated glycosaminoglycans reduces the electrophoretic mobility of vascular endothelial cells.

The main purpose of this work was to identify the macromolecules carrying the surface charge of endothelial cells. This was done by measuring changes in cell electrophoretic mobility caused by enzymatic removal of glycocalyx components. Endothelial cells were removed from the bovine pulmonary artery using nonenzymatic procedures, plated, and identified by immunocytochemical methods and electron microscopy. Cultured cells were suspended in saline and placed in the lumen of a capillary in a Rank Brothers electrophoresis instrument. Voltage was applied between the ends of the capillary, and the velocity acquired by the cells was measured with a microscope. Preincubating the cells in protein-free saline for 1 h reduced the mobility by 25%. This reflects the loss of proteoheparan sulfate from the cell surface. Cell mobility was totally suppressed by exposing the entire cell surface to chondroitin sulfate lyase, but it was only slightly diminished when the enzyme was applied only to the cell side facing the culture medium. A partial decrease in mobility was obtained after enzymatic removal of either heparin, heparan sulfate, or collagen. The results indicate that sulfated glycosaminoglycans are the main carriers of the surface change in vascular endothelial cells. The asymmetrical effect of chondroitinase on the two sides of the cell indicates a distribution polarization for glycosaminoglycans in endothelial cells.

Animals↗