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Biomedical subjects

P Gay

Publications and source records attributed to P Gay.

At least 55 records · Page 3Linked to original sources
PubMed1977

Fructose transport in Bacillus subtilis.

The transport of fructose in Bacillus subtilis was studied in various mutant strains lacking the following activities: ATP-dependent fructokinase (fruC), the fructose 1-phosphate kinase (fruB) the phosphofructokinase (pfk), the enzyme I of the phosphoenolpyruvate phosphotransferase system (the thermosensitive mutation ptsI1), and a transport activity (fruA). Combinations of these mutations indicated that the transport of fructose in Bacillus subtilis is tightly coupled to its phosphorylation either in fructose 1-phosphate, identified in vivo and in vitro or in fructose 6-phosphate identified by indirect lines of evidence. These steps of fructose metabolism were shown to depend on the activity of the enzyme I of the phosphoenolpyruvate phosphotransferase systems. The fruA mutations affect the transport of fructose when the bacteria are submitted to catabolite repression. The mutations were localized on the chromosome of Bacillus subtilis in a cluster including the fruB gene. When grown in a medium supplemented by a mixture of potassium glutamate and succinate the fruA mutants are able to carry on the two vectorial metabolisms generating fructose 6-phosphate as well as fructose 1-phosphate. A negative search of strictly negative transport mutants in fruA strains indicated that more than two structural genes are involved in the transport of fructose.

Bacillus subtilis↗
PubMed1976

Phosphorylation of intracellular fructose in Bacillus subtilis mediated by phosphoenolpyruvate-1-fructose phosphotransferase.

Intracellular fructose provided by the sorbitol pathway in Bacillus subtilis can be phosphorylated by the phosphenolpyruvate-1-fructose phosphotransferase which is known to mediate a vectorial metabolism. The fate of this intracellular fructose was studied using mutants lacking either the fructose 1-phosphate pathway or the fructose 6-phosphate pathway. It was shown that the phosphoenolpyruvate-dependent phosphorylation needs a prior exit of the sugar into the medium, this exit being probably catalysed by a transport system. A low affinitiy intracellular phosphenolpyruvate phosphotransferase system was found, which seems to be devoid of a physiological role.

Bacillus subtilis↗
PubMed1975

A fundal cyst of the gallbladder: An unusual abdominal mass.

A female, aged 80 years, presenting with a large abdominal mass causing distension and right-sided hydronephrosis, is presented. The mass proved to be a unilocular cyst attached to the fundus of a thick-walled gallbladder. Histological examination demonstrated invasive adenocarcinoma in the gallbladder. The cyst was lined by gallbladder type epithelium which showed the appearances of carcinoma-in-situ. The aetiology of this cystic lesion is discussed. It seems most likely that it is an acquired lesion caused by occlusion of the communication into a fundal diverticulum. This lesion is unusual, but should be considered in the differential diagnosis of obscure intraabdominal masses.

Adenocarcinoma↗
PubMed1975

Existence of two alternative pathways for fructose and sorbitol metabolism in Bacillus subtilis Marburg.

Strains of Bacillus subtilis mutated for fructose phosphotransferase system (fruA), fructose-1-phosphate kinase (fruB), fructokinase (frucC) have been tested for their catabolism of sorbitol and fructose. It is shown that the previously known pathways of sorbitol and fructose degradation in B. subtilis, e.g.: (see article) may metabolize intracellular fructose produced either by sorbitol oxidation or by fructose-1-phosphate dephosphorylation. The intracellular fructore degradation via fructose-1-phosphate kinase has been found to require the fructose phosphotransferase system which ensures a vectorial transport of fructose.

Bacillus subtilis↗
PubMed1975

Identification of the structural gene of the PEP-phosphotransferase enzyme I in Bacillus subtilis Marburg.

A thermosensitive mutation pt8I1 in the gene coding for the Enzyme I of the PEP-phosphotransferase system pathway has been isolated. The mutant enzyme was shown to be sensitive to high temperature, but this effect is dependent on the ionic strength. The ptsI1 mutation was shown to belong to the previously described ctr locus. Following Lin (1970) it is proposed to retain the symbole ptsI for this locus.

Bacillus subtilis↗