Showing papers on "Protoporphyrins published in 2009"
TL;DR: It is concluded that the protein site that hosts these sensitizers accommodates different analogs at positions that differ slightly from each other, manifested in the ease of access of iodide from the external aqueous phase, and in the proximity of the photosensitizers to the tryptophan.
Abstract: In previous studies, we demonstrated that elongation of side chains of several sensitizers endowed them with higher affinity for artificial and natural membranes and caused their deeper localization in membranes. In the present study, we employed eight hematoporphyrin and protoporphyrin analogs and four groups containing three chlorin analogs each, all synthesized with variable numbers of methylenes in their alkyl carboxylic chains. We show that these tetrapyrroles’ affinity for bovine serum albumin (BSA) and their localization in the binding site are also modulated by chain lengths. The binding constants of the hematoporphyrins and protoporphyrins to BSA increased as the number of methylenes was increased. The binding of the chlorins depended on the substitution at the meso position opposite to the chains. The quenching of the sensitizers’ florescence by external iodide ions decreased as the side chains became longer, indicating to deeper insertion of the molecules into the BSA binding pocket. To corroborate this conclusion, we studied the efficiency of photodamage caused to tryptophan in BSA upon illumination of the bound sensitizers. The efficiency was found to depend on the side-chain lengths of the photosensitizer. We conclude that the protein site that hosts these sensitizers accommodates different analogs at positions that differ slightly from each other. These differences are manifested in the ease of access of iodide from the external aqueous phase, and in the proximity of the photosensitizers to the tryptophan. In the course of this study, we developed the kinetic equations that have to be employed when the sensitizer itself is being destroyed.
12 citations
TL;DR: To the Editor: In the recent report by Vera et al1 with an associated editorial commentary by N.G. Abraham, cobalt protoporphyrin (CoPP) is used as an inducer of heme oxygenase-1 to CoPP.
Abstract: To the Editor:
In the recent report by Vera et al1 with an associated editorial commentary by N.G. Abraham,2 cobalt protoporphyrin (CoPP) is used as an inducer of heme oxygenase-1 to …
3 citations
TL;DR: In these studies, CO(III) protoporphyrin IX chloride obtained from Frontier Laboratories was used as a raw material for the studies on soluble guanylyl cyclase and the antihypertensive actions of heme oxygenase-1 induction in the kidney.
Abstract: We would like to thank Dr. Danziger1 for his interest in our work and his thoughtful commentary about the role of soluble guanylyl cyclase (sGC) in mediating the antihypertensive actions of heme oxygenase-1 (HO-1) induction in the kidney. In our studies, we used CO(III) protoporphyrin IX chloride obtained from Frontier …