Chiral memory and self-replication study of porphyrin and bilirubin aggregates formed on polypeptide matrices

Abstract

Porphyrin heteroaggregates composed of meso-tetrakis(N-methylpyridinium-4-yl)porphinatocopper(II) and meso-tetrakis(4-sulfonatophenyl)porphyrin formed in the presence of a polyglutamic matrix possess chiral memory and an ability to self-replicate their supramolecular structures. By means of electronic circular dichroism spectroscopy, it has been shown that the self-replication process is not influenced by changes in pH or ionic strength. The average molecular weight of the polyglutamic matrix used for porphyrin aggregate preparation plays a crucial role with regard to the form of the resulting CD spectrum. In the second part of our study, a complex composed of polylysine and bilirubin as a model system for a structured homoaggregate formed on the chiral matrix has been tested for chiral memory phenomena. The results indicate that the bilirubin homoaggregate shows chiral memory.

Keywords:

• porphyrins
• chiral memory
• self-assembly
• self-replication
• bilirubin
• ECD

Acknowledgements

This work was supported by research grants from the Ministry of Education, Youth and Sports of the Czech Republic (MSM 6046137307, OC135) and from the Grant Agency of the Academy of Sciences of the Czech Republic (IAA 400550702).