Azurin and HS^–: Towards Implementation of a Sensor for HS^– Detection

Abstract

Hydrogen sulfide (H 2 S) is an important biological messenger, which recently joined nitric oxide (NO) and carbon monoxide (CO) as an endogenously produced gasotransmitter. This discovery resulted in a renewed interest towards H 2 S and, in particular, in its reactivity with biological and bioinorganic targets. However, in the scientific literature studies exploring the reactivity of H 2 S/HSwith non-heme proteins are rare. In this work, we studied the interaction of HSwith the natural metalloprotein Cu-azurin and its cobalt variant via UV-Vis, fluo- [a]

Activity-Based Fluorescent Probes for Hydrogen Sulfide and Related Reactive Sulfur Species

“…(b) Fluorescence response of Atto 620-labeled Cu-azurin 938 after addition of 50 μM NaSH and 80 μM K 3 [Fe­(CN) 6 ]. Reproduced with permission from ref . Copyright 2019 American Chemical Society.…”

“…This change in absorbance resulted in fluorescence turn-off from the Atto620 dye upon H 2 S addition. Strianese and Palm reported a related example in investigating the reaction of H 2 S with the metalloprotein Cu-azurin 938 as well as its Co 2+ adduct 939 944. For 938, addition of H 2 S to a buffered aqueous solution bleached the 550−650 nm absorbance, which could be restored by addition of the oxidant K 3 [Fe(CN) 6 ], suggesting that addition of H 2 S results in Cu 2+ reduction rather than Cu precipitation and formation of the apoprotein.…”

Effect of Metal Coordination Environment on the Stability of Zinc Complexes and Their Reactivity with NaSH

“…[12][13][14][15][16] In this context, motivated by our aim of clarifying the reactions H 2 S is involved in, our studies on the coordination of H 2 S to transition metals started a few years ago and focused both on properly tailored low molecular weight metal complexes and on natural metalloproteins. [17][18][19][20][21][22][23][24] Recently we and others focused on the synthesis of fluorescent salen-based zinc complexes. [25][26][27][28][29][30][31][32][33][34][35] It was of interest to establish how the 'hardness/softness' of imine and amine nitrogens (which chelate the zinc centers) of the resulting complexes may affect the HS À binding.…”

Sol-Gel Dipping Devices for H2S Visualization

“…Notwithstanding this, the study of the bioinorganic chemistry of hydrogen sulfide has been ongoing for some time [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] and still represents an active area of study [ 16 ]. Studies demonstrating the signaling pathways involving the metalloproteins together with the evidence implicating H 2 S/HS − in an increasing number of biological processes inspired most of the recent studies on the metal-based chemistry of H 2 S. Both natural and synthetic systems have been proposed as new examples of metal complexes capable of coordinating H 2 S/HS − [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Considering the very flexible and attractive optical properties of salen-based zinc complexes [ 33 , 34 , 35 , 36 , 37 , 38 ], and motivated by our interest in the coordination of H 2 S to the transition metals, we focused on salen-based zinc systems and studied their reactivity with H 2 S/HS − [ 39 , 40 , 41 , 42 , 43 ].…”