REAL

In situ detection of ALA-stimulated porphyrin metabolic products inEscherichia coli B by fluorescence line narrowing spectroscopy

Szocs, K. and Csik, Gabriella and Kaposi, András Dezső and Fidy, Judit (2001) In situ detection of ALA-stimulated porphyrin metabolic products inEscherichia coli B by fluorescence line narrowing spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH, 1541 (3). pp. 170-178. ISSN 0167-4889

[img] Text
1294849.PDF
Restricted to Registered users only

Download (406kB) | Request a copy

Abstract

In a recent work [Photochem. Photobiol. B: Biol. 50 (1999) 8] the successful photodynamic inactivation of Escherichia coli bacteria by visible light was reported based on delta -aminolevulinic acid (ALA)-induced endogenous porphyrin accumulation. In this work, the identification of these porphyrin derivatives in intact bacteria was performed by low-temperature conventional fluorescence and fluorescence line narrowing (FLN) techniques. Conventional fluorescence emission spectroscopy at cryogenic temperatures revealed the presence of the free-base porphyrins, identified earlier by high-performance liquid chromatography analysis of disintegrated bacterial cells after ALA induction; however, emission maxima characteristic for metal porphyrins were also observed. We demonstrated that the primary reason for this signal is that metal porphyrins are formed from free-base porphyrins by Mg2+ ions present in the culturing medium. Incorporation of Zn ions originating from the glassware could also be supposed. In the FLN experiment, the energy selection effect could be clearly demonstrated for (0,0) emissions of both the free-base and the metal porphyrins. The comparison of the conventional emission spectra and the bands revealed by the FLN experiment show that the dominant monomeric structural population is that of metal porphyrins. The intensity and the shape of the FLN lines indicate an aggregated population of the free-base porphyrins, beside a small monomeric population. (C) 2001 Elsevier Science B.V. All rights reserved.

Item Type: Article
Subjects: Q Science / természettudomány > QH Natural history / természetrajz > QH301 Biology / biológia > QH3011 Biochemistry / biokémia
Q Science / természettudomány > QH Natural history / természetrajz > QH301 Biology / biológia > QH3015 Molecular biology / molekuláris biológia
SWORD Depositor: MTMT SWORD
Depositing User: MTMT SWORD
Date Deposited: 09 Jul 2014 06:13
Last Modified: 09 Jul 2014 06:13
URI: http://real.mtak.hu/id/eprint/13607

Actions (login required)

View Item View Item