Streptavidin Reduces Oxygen Quenching of Biotinylated Ruthenium(II) and Palladium(II) Complexes

Abstract

Transition metal complexes such as biotinylated ruthenium(II) tris(bipyridyl) and palladium(II) porphyrin show an increase in luminescence intensity and lifetime upon binding to streptavidin in aqueous solution. Here we show that this increase of luminescence lifetime and intensity are caused by the shielding of the transition metal complexes from dissolved oxygen through streptavidin rather than by hydrophobicity effects as recently claimed.

Application of d6 transition metal complexes in fluorescence cell imaging

“…Another study of biotinylated Ru complexes using time-resolved techniques found that the luminescence enhancement of biotinylated Ru species upon coordination with streptavidin is due to the shielding of the complex from dissolved oxygen rather than a hydrophobic effect, as the enhancement is not observed in previously de-aerated solution. 111 This result brings into question the nature of similar previously attributed to hydrophobicity. Other biotinylated Ru species can be used as fluorescent markers in cell biology or as detection or quantifying agents in biochemistry.…”

Synthesis, Characterization and Luminescence Properties of Dipyridin‐2‐ylamine Ligands and Their Bis(2,2′‐bipyridyl)ruthenium(II) Complexes and Labelling Studies of Papain from Carica papaya

“…Similarly, it was also observed that binding of a polypyridyl Ru II derivative of biotin to streptavidin enhanced the luminescence of the probe by shielding it from dissolved dioxygen. [26] By analogy, the position of the anchoring group within the enzyme's active site could place the probes in such an environment that they may be at least partially protected against O 2 quenching. Indeed, the emission intensity of 3b was quenched by 30 % in the presence of dioxygen, whereas that of PAP-3b was quenched by only 12 %.…”

Streptavidin as a Scaffold for Light‐Induced Long‐Lived Charge Separation

“…[18][19][20][21][22][23][24][25][26][27][28] This effort was inspired by av isionary publication by Whitesides and resulted in av ariety of other applications. [23,[29][30][31][32][33] In a related context, several studies on the luminescence properties of (strept)avidin-embedded biotinylated d 6 -metal complexes, including ruthenium(II) polypyridines, [34][35][36][37] rhenium(I) tricarbonyl diimines, [38][39][40][41][42] and cyclometalated iridium(III) complexes [43][44][45][46][47][48] suggest that such protein-based systems are well-suited for the generationo fp hoto-induced chargeseparation. [49] In ar ecent study, [50] we covalently anchored [Ru(bpy) 2 (phenNHCOCH 2 Br)](PF 6 ) 2 (bpy = 2,2'-bipyridine, phen = phenanthroline) to four different Sav isoformsb earing as ingle cysteine residue per monomer( Figure 1).…”

“…This effort was inspired by a visionary publication by Whitesides and resulted in a variety of other applications . In a related context, several studies on the luminescence properties of (strept)avidin‐embedded biotinylated d 6 ‐metal complexes, including ruthenium(II) polypyridines, rhenium(I) tricarbonyl diimines, and cyclometalated iridium(III) complexes suggest that such protein‐based systems are well‐suited for the generation of photo‐induced charge separation …”