Spectroscopic and Molecular Docking Study of the Interaction between Neutral Re(I) Tetrazolate Complexes and Bovine Serum Albumin

Abstract

Re(I) complexes have potential in biomedical sciences as imaging agents, diagnostics and therapeutics. Thus, it is crucial to understand how Re(I) complexes interact with carrier proteins, like serum albumins. Here, two neutral Re(I) complexes were used (fac‐[Re(CO)3(1,10‐phenanthroline)L], in which L is either 4‐cyanophenyltetrazolate (1) or 4‐methoxycarbonylphenyltetrazole ester (2), to study the interactions with bovine serum albumin (BSA). Spectroscopic measurements, calculations of thermodynamic and Förster resonance energy transfer parameters, as well as molecular modelling, were performed to study differential binding between BSA and complex 1 and 2. Induced‐fit docking combined with quantum‐polarised ligand docking were employed in what is believed to be a first for a Re(I) complex as a ligand for BSA. Our findings provide a basis for other molecular interaction studies and suggest that subtle functional group alterations at the terminal region of the Re(I) complex have a significant impact on the ability of this class of compounds to interact with BSA.

Synthesis and cellular uptake of neutral rhenium(i) morpholine complexes

“…S1-S14 and S19-S24 †). Similar to previously reported rhenium complexes, 24,25 the central rhenium node adopts a slightly distorted octahedral geometry, displaying the three carbonyl ligands in a facial configuration.…”

Rhenium(I) conjugates as tools for tracking cholesterol in cells

“…All cell lines were maintained in RPMI culture medium supplemented with 10% fetal bovine serum for 24 h, once seeded for experiments. Following 24 h, the culture medium was replaced with fresh RPMI culture medium containing no fetal bovine serum and cells were incubated for a further 24 h. Serum starvation was applied as serum contains albumin which interacts with neutral Re(I) complexes, affecting their emission properties 43 and which may enhance cholesterol efflux from cells. 44 , 45 It also contains cholesterol which would likely interfere with ReTEGCholestanol uptake.…”

Fluorescence Microscopy—An Outline of Hardware, Biological Handling, and Fluorophore Considerations

“…Culture media are multicomponent solutions, containing various micro and macro elements, vitamins, proteins, fatty acids, and pH indicators, which can themselves be fluorescent or can interfere with the fluorescent properties of a given fluorophore [ 47 ]. For example, phenol red, present in most culture media, is fluorescent when excited at ~400 nm [ 47 , 48 ] and some vitamins (e.g., riboflavin and pyridoxal) increase photobleaching of GFP [ 49 ], while serum albumin can bind to some fluorescent probes to alter their spectral properties [ 50 , 51 ]. Concentrations of dyes also need to be carefully optimised to ensure specific staining of target structures or molecules.…”