ABSTRACT
A 48-year-old female patient was found to have a paraumbilical vein saccular aneurysm, which is a rare consequence of portal hypertension. She presented with right upper quadrant pain and had a known diagnosis of alcoholic liver disease. This had progressed since her last admission. We discuss the multimodality images obtained, diagnosis and complications associated with this pathology.
ABSTRACT
The unsaturated side chain of l-propargylglycine (Pra) was used to study parahydrogen-induced polarization (PHIP) in synthetic oligopeptides. For the first time PHIP-induced NMR signal enhancement was demonstrated using model peptides bearing various functional side chains.
Subject(s)
Alkynes/chemistry , Glycine/analogs & derivatives , Oligopeptides/chemical synthesis , Amino Acid Sequence , Catalysis , Glycine/chemistry , Hydrogen/chemistry , Hydrogenation , Magnetic Resonance Spectroscopy , Oligopeptides/chemistry , Sulfhydryl Compounds/chemistrySubject(s)
Nickel/metabolism , Organometallic Compounds/metabolism , Superoxide Dismutase/metabolism , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Conformation , Nickel/chemistry , Organometallic Compounds/chemistry , Reactive Oxygen Species/metabolism , Stereoisomerism , Superoxide Dismutase/chemistryABSTRACT
During recent years several peptide-based Ni superoxide dismutase (NiSOD) models have been developed. These NiSOD models show an important structural difference compared to the native NiSOD enzyme, which could cause a completely different mechanism of superoxide dismutation. In the native enzyme the peptide bond between Leu4 and Pro5 is cis-configured, while the NiSOD models exhibit a trans-configured peptide bond between these two residues. To shed light on how the configuration of this single peptide bond influences the activity of the NiSOD model peptides, a new cis-prolyl bond surrogate was developed. As surrogate we chose a leucine/alanine-based disubstituted 1,2,3-triazole, which was incorporated into the NiSOD model peptide replacing residues Leu4 and Pro5. The yielded 1,5-disubstituted triazole nickel peptide exhibited high SOD activity, which was approximately the same activity as its parent trans-configured analogue. Hence, the conformation of the prolyl peptide bond apparently has of minor importance for the catalytic activity of the metallopeptides as postulated in literature. Furthermore, it is shown that the triazole metallopeptide is forming a stable cyanide adduct as a substrate analogue model complex.
