[D-Ala2,Leu5]Enkephalin was readily metabolized by membranes (40,000 g pellet) prepared from heads of the housefly, Musca domestica, with Gly3-Phe4 being the major site of cleavage. This hydrolysis was only partially inhibited (40%) by 10 microM phosphoramidon, an inhibitor of endopeptidase-24.11, but was almost totally abolished in the presence of a mixture of 10 microM phosphoramidon and 10 m...

We applied one of the highly sensitive proteomic approaches, i.e. Multidimensional Protein Identification Technology (MudPIT), to determine protein alterations, qualitatively and quantitatively in plasma samples collected before, during, after spaceflights from same astronauts. These were prepared blood drawn acid-citrate dextrose (ACD) tubes. Samples four recruited astronauts available for ana...

Isoaspartyl dipeptidase (IadA) is an enzyme that catalyzes the hydrolysis of an isoaspartyl dipeptide-like moiety, which can be inappropriately formed in proteins, between the β-carboxyl group side chain of Asp and the amino group of the following amino acid. Here, we have determined the structures of an isoaspartyl dipeptidase (CpsIadA) from Colwellia psychrerythraea, both ligand-free and that...

The most sensitive nonradiometric routine assay for angiotensin-converting enzyme (ACE) activity uses fluorometry to detect His-Leu released from Hip-His-Leu. Our results indicate that, in contrast to human serum, rat serum and plasma contain large and variable amounts of dipeptidase activity that lead to a subestimation of the ACE activity measured in 0.1 M potassium phosphate buffer, pH 8.3, ...

GSH metabolism in yeast is carried out by the gamma-glutamyl cycle as well as by the DUG complex. One of the last steps in the gamma-glutamyl cycle is the cleavage of Cys-Gly by a peptidase to the constitutent amino acids. Saccharomyces cerevisiae extracts carry Cys-Gly dipeptidase activity, but the corresponding gene has not yet been identified. We describe the isolation and characterization o...

Recombinant plant-type asparaginases from the cyanobacteria Synechocystis sp. PCC (Pasteur culture collection) 6803 and Anabaena sp. PCC 7120, from Escherichia coli and from the plant Arabidopsis thaliana were expressed in E. coli with either an N-terminal or a C-terminal His tag, and purified. Although each of the four enzymes is encoded by a single gene, their mature forms consist of two prot...