Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania.
Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania.
J Inorg Biochem. 2018 Feb;179:32-39. doi: 10.1016/j.jinorgbio.2017.10.015. Epub 2017 Nov 10.
The present study reports findings regarding the contrast between HS interaction with bovine hemoglobin (Hb) and horse heart myoglobin (Mb), in terms of binding and dissociation kinetics, affinities, and mechanism. At pH9.5, oxidation of ferric-sulfide adducts in presence of no free sulfide, using hexachloroiridate as oxidant is examined using stopped-flow UV-vis, EPR, vibrational spectroscopy and mass spectrometry. Oxidation of the ferric-sulfide adduct in such conditions occurs with a putative unstable Fe(IV)-sulfide adduct as intermediate that finally leads to a paramagnetic ferric species with distinct EPR features. As detected by MS spectrometry, this final species appears to be a truncated form of globin at a distinct Tyr. In case of Hb, only β-chain is truncated at Tyr144.
本研究报告了有关 HS 与牛血红蛋白（Hb）和马心肌红蛋白（Mb）相互作用的对比，涉及结合和解离动力学、亲和力和机制。在 pH9.5 下，使用六氯合铱酸盐作为氧化剂，在没有游离硫的情况下，检查了亚铁-硫化物加合物在存在下的氧化情况，使用停流紫外可见光谱、EPR、振动光谱和质谱法进行了检查。在这种条件下，铁-硫化物加合物的氧化会产生一个假定的不稳定的 Fe(IV)-硫化物加合物作为中间体，最终导致具有独特 EPR 特征的顺磁铁物种。如 MS 光谱检测到的，这种最终物种似乎是一种截断的球蛋白形式，位于特定的 Tyr 处。在 Hb 的情况下，只有β链在 Tyr144 处被截断。
