Biomedical subjects

G Roscetti

Publications and source records attributed to G Roscetti.

23 records · Page 2Linked to original sources

PubMed1986

In vitro interaction of opioid peptides with phospholipids. III. The role of lipid.

The binding of tritiated Leu-enkephalin to phosphatidylserine and phosphatidylcholine vesicles, both unmodified and modified by the incorporation of free fatty acid, has been studied by steric exclusion chromatography, ultraviolet difference spectroscopy and fluorescence anisotropy. The results obtained tend to confirm that both ionic and hydrophobic interactions are important in the binding phenomena. On the other hand, it seems likely that steric factors play a very limited role in the recognition of the phospholipid by the opioid peptide. Finally, these results confirm the existence of three complexes of different size, as already demonstrated. But, unlike the previously presented results, they stress the importance of the larger of the three complexes formed through binding.

Chromatography, Gel↗

PubMed1985

Peripheral enkephalin hydrolysis in different animal species: a comparative study.

Using column and thin layer chromatography, plasma hydrolysis of leu-enkephalin has been studied in man and several laboratory animals. The hydrolysis kinetics determined in the various species examined are considerably different. In addition, also the enzyme forms evidentiated, their molecular weight distribution and relative ratios have been found to vary greatly in the animals under test. Our data suggest that the widely different hydrolysis kinetics reported by various authors are attributable to the differences between species, rather than to differences in the analytical techniques employed.

Aminopeptidases↗

PubMed1985

Mechanisms of leu-enkephalin hydrolysis in human plasma.

The present work describes the kinetics of enkephalin hydrolysis by plasma enzymes and the fragmentation pattern of both the parent peptide and of the first hydrolysis by-products. The degradation kinetics were followed by positive identification of the hydrolysis fragments by chromatographic methods, by amino acid analysis and by scintillation counting of tritium-labeled enkephalin. In addition, the results presented confirm the role of the low molecular weight plasma components in the control of the hydrolysis of the peripherally-released enkephalins.

Amino Acids↗

PubMed1984

A cell division-active protein from E. coli.

A purification procedure for a protein obtained from an pathogenic strain of E. coli is described. The protein-called CNF-is active in inhibiting the duplication of cultured mammalian cells. Since nuclei division is apparently normal, treatment of cultured cells with CNF leads to the formation of gigantic, polynucleated cells. The purified protein is chromatographically and electrophoretically homogeneous. A partial characterization of CNF protein is also given.

Amino Acids↗

PubMed1984

In vitro interaction of opioid peptides with phospholipids. Formation and characterization of complexes.

Interaction of Leu- and Met-enkephalin with phosphatidylserine has been studied by chromatographic and spectrophotometric techniques. The main results of our investigation may be summarized as follows: i) Both enkephalins bind to phosphatidylserine; ii) no difference between the two enkephalins is noticeable; and iii) with both peptides the binding phenomenon leads to the formation of two complexes with a definite stoichiometry which are sterically much smaller than the original vesicles. On the basis of the submitted data, a tentative model of the newly formed complexes is provided.

Acylation↗