Oligo- and polypeptide conjugates of cationic porphyrins: binding, cellular uptake, and cellular localization

Abstract

Recently we have characterized the DNA and nucleoprotein (NP) binding of bis(4-Nmethylpyridyl)-15,20-di(4-carboxyphenyl)porphyrin (BMPCP) and meso-tri(4-Nmethylpyridyl)-mono(4-carboxyphenyl)porphyrin (TMPCP) and their tetra-peptide conjugates (BMPCP-4P 2 and TMPCP-4P, respectively). In this work we investigated the interaction of TMPCP conjugated to the tetra-peptide branches of branched chain polymeric polypeptide with poly-L-lysine backbone (AK) with DNA or NP using spectroscopic methods.Analysis of absorption spectra revealed the external binding, but no intercalation of TMPCP-AK to DNA. There was no evidence for the interaction between TMPCP-AK and encapsidated DNA. Furthermore, we examined the cellular uptake of BMPCP and TMPCP and their tetra-or polypeptide conjugates by flow cytometry and analyzed how charge, size and structure of the compounds affect their incorporation. In comparison, liposomal association constants of these derivatives were determined. BMPCP-4P 2 accumulated the most, and porphyrins with two positive charges (BMPCP and BMPCP-4P 2 ) showed better accumulation than the tri-cationic TMPCP or TMPCP-4P.Cellular uptake of polycationic TMPCP-AK was significantly lower than that of the free or tetra-peptide conjugated derivatives. The sub-cellular localization of all the five compounds was investigated in co-localization studies by confocal microscopy with special attention to their nuclear localization. Neither free nor conjugated BMPCP or TMPCP were co-localized with nuclear marker. Instead, these derivatives showed co-localization with lysosomal and mitochondrial fluorescent probes. TMPCP-AK conjugate had different localization pattern appearing mainly in mitochondria and cytoplasmic vesicles.Our results may contribute to the further design of DNA targeting porphyrin based constructs.

Evaluation of Amino-Functional Polyester Dendrimers Based on Bis-MPA as Nonviral Vectors for siRNA Delivery

“…Similar mitochondrial localization for the polyester dendrimers, without the rhodamine label, cannot be entirely concluded in this study. However, it is in accordance with the previous reasoning on the discrepancy between the MTT and LDH assays, and numerous cationic species have been shown to selectively localize in mitochondria [ 54 , 55 , 56 , 57 , 58 ]. As for most nanoparticles, the probable cell entrance of the Bis-MPA dendrimers is by endocytosis.…”

Sequence modification of heptapeptide selected by phage display as homing device for HT-29 colon cancer cells to improve the anti-tumour activity of drug delivery systems

“…Intracellular localization studies were conducted with a Zeiss 710 confocal microscope (Carl Zeiss Microscopy, Jena, Germany), as described in [22]. Briefly, Dau-peptide conjugates were added to a final concentration of 50 µM in RPMI medium to the cells and incubated for…”

“…The release of the active metabolite from the parent (3) and the most active (13,19,22) conjugates was investigated in rat liver lysosomal homogenate. Very fast decomposition was observed in all cases that did not depend on the sequence of the homing peptide ( Fig.…”

(-)-Epigallocatechin-3-gallate encapsulated realgar nanoparticles exhibit enhanced anticancer therapeutic efficacy against acute promyelocytic leukemia

“…Antiproliferative activity and uptake of RNPs into HL-60 cells were evaluated to determine whether the antiproliferative effect of nano-realgar on HL-60 cells was related to release characteristics of realgar from EGCG-RNPs (Orosz et al., 2017).…”