Université de Neuchâtel

Determination of Intracellular Prolyl/Glycyl Proteases in Intact Living Human Cells and Protoporphyrin IX Production as a Reporter System

Berger, Yann ; Chapuis Bernasconi, Catherine ; Schmitt, Frédéric ; Neier, Reinhard ; Juillerat-Jeanneret, Lucienne

In: Chemistry & Biology, 2005, vol. 12, no. 8, p. 867-872

The determination of enzyme activity or inhibition in intact living cells is a problem in the development of inhibitors for intracellular proteases. The production of fluorescent protoporphyrin IX (PpIX) from the nonfluorescent (N)-Gly/Pro-5-aminolevulinic acid (ALA) substrates was used to evaluate the prolyl/glycyl-specific dipeptidylpeptidase IV (DPPIV)-like and prolyloligopeptidase (POP)-like...

Université de Neuchâtel

Evaluation of dipeptide-derivatives of 5-aminolevulinic acid as precursors for photosensitizers in photodynamic therapy

Berger, Yann ; Ingrassia, Laurent ; Neier, Reinhard ; Juillerat-Jeanneret, Lucienne

In: Bioorganic & Medicinal Chemistry, 2003, vol. 11, no. 7, p. 1343-1351

N-terminal-blocked and N-terminal-free pseudotripeptide Gly-Gly and Gly-Pro derivatives of 5-aminolevulinic acid (ALA) esters were synthesized as potential specific substrates for cellular peptidases and precursors for the production of the photosensitizer protoporphyrin IX (PpIX). These precursors were evaluated using human cell lines of either carcinoma or endothelial origin. N-blocked or...

Université de Neuchâtel

Synthèse de dérivés de l'acide d-aminolévulinique, capable de cibler des cellules spécifiques, en vue de leur utilisation en thérapie photodynamique

Berger, Yann ; Neier, Reinhard (Dir.)

Thèse de doctorat : Université de Neuchâtel : 2002 ; 1665.

When 5-aminolevulinic acid (ALA) is administered topically, intravenously or intraperitoneally to tumor-bearing animals or humans, tumour selective production of protoporphyrin IX (PpIX) is frequently observed. Several biophysical, biochemical and physiological factors explain this tumour selectivity, among which the most important ones seem to be: ·A relatively high concentration of the...