Influence of hemoglobin and albumin on the NO donation effect of tetranitrosyl iron complex with thiosulfate

A nitrosyl iron complex with 3.4-dichlorothiophenolyl ligands: synthesis, structures and its reactions with targets – carriers of nitrogen oxide (NO) in vivo

“…11b, the effective rate constant decreases (from 10.9 × 10 −5 s −1 to 6.3 × 10 −5 s −1 ) with increasing protein concentration (from 3.7 × 10 −6 M to 6.7 × 10 −6 M), which is typical of model protein systems. 74,79 It is important to note that we do not observe the formation of nitrites (NO oxidation products) in the buffer at such low concentrations of the initial complex (3 × 10 −5 M), while NO is generated in a prolonged manner in the system with HbO 2 . Obviously, in the presence of HbO 2 , as in the case of BSA, the decomposition of the complex will occur by mechanisms different from the buffer solutions.…”

“…11b, the effective rate constant decreases (from 10.9 × 10 −5 s −1 to 6.3 × 10 −5 s −1 ) with increasing protein concentration (from 3.7 × 10 −6 M to 6.7 × 10 −6 M), which is typical of model protein systems. 74,79 It is important to note that we do not observe the formation of nitrites (NO oxidation products) in the buffer at such low concentrations of the initial complex (3 × 10 −5 M),…”

“…The study of the interaction of complex 1 with hemoglobins Hemoglobins are of interest both as targets for the binding of NICs and their decomposition products, 21 and from the point of view of model systems for assessing the NO-donor activity of the complexes. 73,74 Previously, we actively used the systems of NICs with Hb, which reacts with NO to form nitrosylated hemoglobin: Hb + NO ↔ HbNO. The equilibrium is strongly shifted towards product formation, the binding rate is close to the diffusion rate, and the binding constant is equal to K = 3 × 10 10 M −1 , 75 and therefore, hemoglobin is a "trap" for NO.…”

Albumin as a prospective carrier of the nitrosyl iron complex with thiourea and thiosulfate ligands under aerobic conditions

“…We have previously demonstrated that DNICs with aliphatic ligands are stabilized on the surface of the protein, which leads to its longer generation of NO. [26][27][28] The [Fe(NO) 2 ] + fragment is coordinated in the hydrophobic pocket with Cys34 and His39 to form Fe (Cys39)(His34)(NO) 2 . 26 The use of the thiosulfate DNIC mixed with BSA, in which a protein-bound complex is formed, leads to better effects compared to the initial thiosulfate DNIC, 29 namely this system inhibits the catalytic activity of mitochondrial membrane-bound enzymes (cytochrome C oxidase and monoamine oxidase A).…”