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A F Cacciapuoti

Publications and source records attributed to A F Cacciapuoti.

5 recordsLinked to original sources
PubMed1990

Microbiological and pharmacokinetic studies of acyl demycinosyltylosin and related tylosin derivatives.

A series of tylosins and acyl derivatives of 23-O-demycinosyltylosin (DMT) were initially tested for in vitro antibacterial activity and serum levels in squirrel monkeys (po) and mice (iv). Overall, the DMT compounds were more active in vitro than the tylosins. Two tetraacylated DMTs, Sch 37644 and Sch 38646, were selected from the initial studies for further evaluation and compared to erythromycin and A-56268 (6-O-methyl erythromycin). Sch 37644 and Sch 38646 were 2 to 8-fold less potent in vitro against Gram-positive bacteria than erythromycin and A-56268. In squirrel monkeys, Sch 37644 (AUC, 19.7 micrograms.hour ml) and A-56268 (21.6 micrograms.hour/ml) had similar serum levels following po administration of 20 mg/kg, while Sch 38646 (11.8 micrograms.hour/ml) and erythromycin (1.5 micrograms.hour/ml) had lower levels. In mice administered 200 mg/kg orally, Sch 37644 (AUC, 19.4 micrograms.hour/ml) and Sch 38646 (15.4 micrograms.hour/ml) had higher serum levels than erythromycin (5.7 micrograms.hour/ml). A-56268 was the most active po macrolide in mouse protection studies (PD50S) against Staphylococci and Streptococci, while Sch 37644 and Sch 38646 were similar to erythromycin.

Animals↗
PubMed1979

Phospholipid metabolism in Neisseria gonorrhoeae: phospholipid hydrolysis in nongrowing cells.

Hydrolysis of cell envelope phospholipids was demonstrated in cells of both autolytic and nonautolytic strains of Neisseria gonorrhoeae that were labeled during growth in the presence of [3H] acetate. The label incorporated into the cellular phospholipids was located exclusively in the fatty acid acyl side chains. Labeled cells were incubated for 2 hr in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid buffer, pH 8.5, containing various additions, and then examined for distribution of 3H in lipids. Ca++ selectively stimulated the deacylation of phosphatidylethanolamine (PE), whereas Mn++ stimulated the deacylation of phosphatidylglycerol (PG). Hydrolysis of phosphatidylethanolamine by phospholipase A was accompanied by the accumulation of lysophosphatidylethanolamine (LPE) and free fatty acids in the cells. Free fatty acids accumulated to a greater extent than lysophosphatidylethanolamine, suggesting that the latter was further hydrolyzed to glycerophosphorylethanolamine (GPE) and free fatty acids by a lysophospholipase. Methanol, ethanol, propanol, and isopropanol, added at concentrations which inhibited growth by 50%, stimulated phospholipase A, but not lysophospholipase activity. Differences in heat inactivation, metal ion requirements, and pH optima suggested that phospholipase A activities with phosphatidylethanolamine or phosphatidylglycerol as substrate and lysophospholipase may be separate enzymes.

Buffers↗
PubMed1978

Cell envelope of Neisseria gonorrhoeae: phospholipase activity and its relationship to autolysis.

The relationship between conditions which permit or inhibit cell lysis and those which promote phospholipid hydrolysis in Neisseria gonorrhoeae was investigated. Suspension of exponential-phase gonococci in buffer in the absence of divalent cations resulted in autolysis but not in phosphlipid hydrolysis. The addition of Ca2+ or Mg2+ to the buffer inhibited autolysis and markedly stimulated the hydrolysis of phosphatidylethanolamine. Incubation of cells in buffer at pH 6 inhibited both autolysis and phospholipid hydrolysis.

Bacteriolysis↗
PubMed1977

Characterization of the fatty acid-sensitive glucose 6-phosphate dehydrogenase from Pseudomonas cepacia.

The adenosone 5'-triphosphate-insensitive glucose 6-phosphate dehydrogenase from Pseudomonas cepacia has been found to be strongly inhibited by long-chain fatty acids and their acyl coenzyme A esters, suggesting that an important role of this isoenzyme might be to provide reduced nicotinamide adenine dinucleotide phosphate for reductive steps in fatty acid synthesis. The enzyme, which has been redesignated the fatty acid-sensitive glucose 6-phosphate dehydrogenase, has been purified to homogeneity using affinity chromatography with nicotinamide adenine dinulceotide phosphate-substituted Sepharose as a key step in the purification. The purified preparations were used to study the immunological properties and subunit composition of the enzyme and its relationship to the adenosine 5'-triphosphate-sensitive glucose 6-phosphate dehydrogenase present in extracts of P. cepacia. Although both enzymes were found to be composed of similar size subunits of about 60,000 daltons, immunological studies failed to demonstrate any antigenic similarity between them. Studies of the sedimentation behavior of the fatty acid-sensitive enzyme in sucrose gradients indicated that its apparent molecular weight is increased in the presence of glucose 6-phosphate and suggest that it may exist in an aggregated state in vivo. Palmitoyl coenzyme A, which strongly inhibited the enzyme, failed to influence its sedimentation behavior.

Acyl Coenzyme A↗