title: Enhancers of the non-peroxidative metal porphyrin chemiluminescence reaction.
abstract: Metal porphyrins catalyse luminol chemiluminescence at pH13 without added peroxide. The effects of 22 different surface active compounds on this reaction were studied using six metal porphyrins and one metal porphyrin conjugate. The most active catalyst was Mn-meso-tetra(4-sulphonatophenyl)porphine. Tween-20 enhanced the activity of this catalyst best at a Tween-20 to luminol ratio of 74:1. However, lauryl sulphate enhanced best at an optimum lauryl sulphate to luminol ratio of over 1000:1 and both detergents enhanced the reaction when present below their critical micelle concentrations. Negatively charged aliphatic compounds such as fatty acids enhanced the reaction but positive-charged aliphatic compounds inhibited it. Small differences in enhancer structure resulted in differing enhancement. For example, linoleic acid enhanced Mn-meso-tetraphenyl porphine more than 10-fold, yet linolenic acid inhibited this catalyst. Conjugation of a metal porphyrin to antibody did not influence its enhancement by detergents. The results indicate that the enhancement mechanism does not require formation of pure detergent micelles but that direct association between enhancer and catalyst may be important.
authors.affiliation: Pharmaceutical Research Division, Takeda Chemical Industries, Ltd, Osaka, Japan.
authors.forename: M A
authors.initials: MA
authors.lastname: Motsenbocker
authors.forename: K
authors.initials: K
authors.lastname: Oda
authors.forename: Y
authors.initials: Y
authors.lastname: Ichimori
mesh_terms: D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008163:Luminescent Measurements; D008165:Luminol; D008665:Metalloporphyrins / Q000032:analysis*; D013501:Surface-Active Agents
chemical_list: D007202:Indicators and Reagents; D008665:Metalloporphyrins; D013501:Surface-Active Agents; D008165:Luminol