Novel Precursors of Fluorescent Dyes. 1. Interaction of the Dyes with Model Phospholipid in Monolayers

Abstract

Photoactivated ("caged") fluorescent dyes are modern tools for structure and function studies of cell membranes and subcellular organelles. Recently synthesized precursors of rhodamine fluorescent dyes (abbreviations PFD813 and PFD814) important for microscopic probing of biological objects have been studied in solution. In order to characterize the behavior at interfaces, monolayers of PFD813 and PFD814 on water have been formed and investigated. The interactions of these precursors with the biomembrane component dimyristoylphosphatidylethanolamine in monolayers at the air-water interface and after transfer to glass plates have been studied by measuring monolayer parameters and spectroscopic properties before and after photo-chemical formation of the fluorescent rhodamine dyes Rho813 and Rho814, respectively.

Conjugates of a Photoactivated Rhodamine with Biopolymers for Cell Staining

“…Some data of similar PFDs (structure, physical-chemical properties, and interactions with lipids in model membranes) was published in the recent papers [ 9 , 18 , 20 ]. In the previous study, the method of cell staining by the most promising precursor PFD of fluorescent dye Rho813 was developed and described in detail [ 19 , 23 ].…”

“…Cells were cultivated and handled in the Institute of Bioorganic Chemistry, Russian Academy of Sciences: human breast carcinoma HBL-100, human keratinocytes HaCaT, human epithelial carcinomas A431 and canine kidney epithelial cells MDCK. Primary cell cultures of human lymphocytes were isolated by standard procedure [ 18 – 21 ]. Cell trackers: MitoTracker Green FM and Hoechst 33342, were purchased from Invitrogen and Sigma-Aldrich, respectively.…”

“…Varying the power of the illuminating light and its location, one can easily vary the number and spatial arrangement of the newly formed fluorescent “probes,” then track their movement, and determine the shape and positioning of cellular and subcellular objects labeled by such dyes. The recent studies [ 17 , 18 ] demonstrate also the possibility of using fluorescent dyes for obtaining 2D and 3D structures of the cells and intracellular objects. Due to their high photostability and excellent photophysical properties, rhodamine dyes can be especially useful as laser dyes, fluorescent standards, and trackers of macromolecular movement, in addition to the abovementioned application as cell fluorescent probes [ 4 – 8 , 10 – 13 ].…”

Bidirectional Photomodulation of Surface Tension in Langmuir Films

“…As a consequence, a surface pressure drop is observed under these conditions (Figure ). Based on our experimental data, we cannot exclude that some of the amphiphilic molecules are expelled from the monolayer at high pressures, thus also decreasing the surface pressure …”