Ibuprofen Impairs Allosterically Peroxynitrite Isomerization by Ferric Human Serum Heme-Albumin

Imatinib binding to human serum albumin modulates heme association and reactivity

“…Of note, values of k on and k 0 for peroxynitrite isomerization obtained according to Eq. (9) in the absence of imatinib are in excellent agreement with those reported in the literature (see [34,35,[39][40][41][42]45,65]). …”

“…The Hill coefficient (n) for imatinib binding to HSA-heme-Fe(III) and trHSA-heme-Fe(III) ranges between 0.99 ± 0.02 and 1.01 ± 0.01, indicating that drug binding to HSA-heme-Fe(III) and trHSA-heme-Fe(III) is a non-cooperative event. Under conditions where the imatinib concentration is much greater than K I , HSA-heme-Fe(III) and trHSA-heme-Fe(III) do not catalyze the isomerization of peroxynitrite as observed in the presence of non-catalytic HSA and cyanide-bound HSA-heme-Fe(III) [45].…”

“…Under all the experimental conditions, a decrease of the absorbance at 302 nm was observed, as previously reported [34,35,39,42,45]. Kinetics of peroxynitrite isomerization was fitted to a single-exponential decay for more than 90% of its course (according to Eq.…”

“…4, panel A). According to the literature (see [39][40][41][42]45] rate-limiting step in catalysis, the conversion of the HSA-hemeFe(III)-OONO and trHSA-heme-Fe(III)-OONO complexes to HSAheme-Fe(III) and trHSA-heme-Fe(III), respectively, and NO 3 À being faster by at least 1 order of magnitude.…”

Evidence for pH-dependent multiple conformers in iron(II) heme–human serum albumin: spectroscopic and kinetic investigation of carbon monoxide binding

“…This first kinetic effect, due to the faster heme binding rate for HDL and LDL, is followed by a slower heme transfer to HSA and hemopexin, which have a higher affinity for heme. Heme binding confers on HSA globin-like spectroscopic and reactivity properties [11,42,44,45]; in addition, HSA-heme has been reported to facilitate scavenging of reactive nitrogen species [46,47]. Furthermore, since the rate of heme transfer from HDL and LDL to HSA and hemoproteins is faster than the heme-induced lipoprotein oxidation [8,48,49], the formation of HSA-heme represents a protective event, which prevents the formation of oxidized HDL and LDL, which are the most oxidatively intolerant plasma components.…”