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Biomedical subjects

A Sedo

Publications and source records attributed to A Sedo.

9 recordsLinked to original sources
PubMed1992

Two-step generation of spirocyclic dipeptides from linear peptide ethyl ester precursors.

Linear tri- and tetrapeptide precursors of 2,5-piperazinedione were prepared and their conversion to spirocyclic dipeptidase enzymes, the spirocyclic dipeptides (SpDp) were generated from the precursors by a two-step mechanism consisting in the proteolytic release of the C-terminal dipeptide ethyl ester and its subsequent spontaneous cyclization. After intraperitoneal administration of urokinase and Ac-Leu-Lys-Gly-Acp-OEt, a SpDp precursor targeted to endogenous plasmin, or the administration of the activated Hageman factor fragment and Ac-Leu-Arg-Ala-Acp-OEt, a SpDp precursor, targeted to endogenous kallikrein, the generated corresponding C-terminal dipeptide ethylester intermediates and SpDp, cyclo(Gly-Acp) and cyclo (Ala-Acp), respectively, were detected in the blood serum of C57B1 mice. Suppression of partial amnesia induced by sodium nitrite was observed in rats where it was subcutaneously administered with H-Leu-Ala-Acp-OEt, a peptide precursor of alaptide, the active SpDp, i.e. cyclo(1-amino-1-cyclopentanecarbonyl-L-alanyl).

Amino Acid Sequence↗
PubMed1991

Dipeptidyl peptidase IV, prolyl endopeptidase and cathepsin B activities in primary human lung tumors and lung parenchyma.

The activities of dipeptidyl peptidase IV (DPP-IV), prolyl endopeptidase (PE) and cathepsin B (CB) were investigated in primary human lung tumours and matched lung parenchyma, using continuous-rate fluorometric assays of the enzymes. Squamous-cell lung carcinomas showed significantly higher specific activities of all three enzymes studied. In lung adenocarcinomas only activities of PE and CB were increased significantly. In a limited number of primary human lung tumours of other histological types the activities of DPP-IV, PE and CB were also elevated. Mixing the matched homogenates of lung tumours and lung parenchyma gave additive activities for each enzyme studied. A significant correlation between tumour/lung ratios of specific activities of DPP-IV and CB was observed.

Adenocarcinoma↗
PubMed1991

Aminopeptidases and angiotensin I-converting enzyme activities in primary human lung tumors and lung parenchyma.

The activities of alanyl aminopeptidase (AAP), arginyl aminopeptidase (RAP), alpha-glutamyl aminopeptidase (EAP) and angiotensin I-converting enzyme (ACE) were investigated in primary human lung tumors of different histological types and in matched lung parenchyma. In contrast to the studied aminopeptidases whose activity differences between tumor and lung tissues were infrequently significant, the activity of ACE was decreased highly significantly in the majority of lung tumors.

Adenocarcinoma↗
PubMed1991

Dipeptidyl peptidase IV in the human lung and spinocellular lung cancer.

The isoelectric point and proportions of soluble and membrane bound dipeptidyl peptidase IV (DPP-IV) in human lung and spinocellular lung cancer tissue were tested. It was found that soluble DPP-IV is relatively less frequent in the cancer than in normal lung tissue. We demonstrated multiple molecular forms of DPP-IV in normal and cancer lung tissues, differing probably not only in the degree of sialylation. DPP-IV from lung cancer tissue consists of more basic molecular forms than that from normal lung tissue. These results suggest that the molecular properties of DPP-IV in normal and cancerous lung tissues may be different.

Carcinoma, Squamous Cell↗
PubMed1989

A kinetic fluorometric assay of dipeptidyl peptidase IV in viable human blood mononuclear cells.

A continuous-rate fluorometric assay of dipeptidyl peptidase IV (DP-IV) in viable human blood mononuclear cells using 7-(L-glycyl-L-prolylamido)-4-methylcoumarin as the substrate is described. The assay method is accurate, rapid, and highly sensitive for measuring the level of cell-surface bound DP-IV activity in suspension of blood mononuclear cells, as well as of other viable cells bearing this enzyme. We believe that the kinetic assay is suitable for studying the regulation of expression and the role of plasma membrane-bound DP-IV on the cellular level.

Cell Separation↗