[Private practice, a sector that attracts male nurses].

Private practice, a sector which attracts male nurses. Although the proportion of women and men within the nursing profession remains stable, the representation of male nurses in private practice has been increasing steadily since 2002 which raises certain questions. This article attempts to explain this phenomenon.

Crystal structures of methionine adenosyltransferase complexed with substrates and products reveal the methionine-ATP recognition and give insights into the catalytic mechanism.

Methionine adenosyltransferases (MATs) are a family of enzymes in charge of synthesising S-adenosylmethionine (SAM), the most important methyl donor present in living organisms. These enzymes use methionine and ATP as reaction substrates, which react in a S(N)2 fashion where the sulphur atom from methionine attacks C5' from ATP while triphosphate chain is cleaved. A MAT liver specific isoenzyme has been detected, which exists in two distinct oligomeric forms, a dimer (MAT III) and a tetramer (MAT I).

Inactivation of S-adenosyl-L-homocysteine hydrolase with novel 5'-thioadenosine derivatives. Antiviral effects.

Synthesis of 5'-S-vinyl-5'-thioadenosine 5, 5'-S-ethynyl-5'-thioadenosine 7 and 5'-S-cyano-5'-thioadenosine 9 is described. Incubation of AdoHcy hydrolase with 5, 7 and 9 resulted in time- and concentration-dependent inactivation of the enzyme and partial depletion of its NAD(+) content. From these results and characterisation of metabolites released during the inactivation process, hypothetical mechanisms are suggested.