کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2048122 | 1074063 | 2012 | 5 صفحه PDF | دانلود رایگان |
To investigate the conformational changes in human tetrameric (αβ)2 hemoglobin upon binding of the first two ligands, we have measured the kinetics of reactions between 4,4′-dithiodipyridine and β93Cys sulfhydryl groups of four diliganded hemoglobins by using CO-bound Fe(II)–Ni(II) hybrids with and without β-β cross-linking. The data show that all the diliganded intermediates have high sulfhydryl reactivities, which are greater than or equal to that for the fully-liganded end state, especially when containing liganded α subunit(s). The results also reveal that both the asymmetrically (α1β1 and α1β2) diliganded species show similar high rates of sulfhydryl reactivity and biphasic kinetics, suggesting a new conformation but only slight functional distortion caused by asymmetric ligation.
► We study the conformational changes induced by partial ligation of hemoglobin.
► Sulfhydryl reactions of β93Cys in metal hybrid hemoglobins are measured.
► All diliganded species show similar or higher reactivity than the final state.
► Both asymmetrical diliganded tetramers exhibit a slight symmetry distortion.
Journal: FEBS Letters - Volume 586, Issue 1, 2 January 2012, Pages 74–78