Mass spectral analysis of asymmetric hemoglobin hybrids:: Demonstration of Hb FS (α2γβs) in sickle cell disease
Mass spectral analysis of asymmetric hemoglobin hybrids:: Demonstration of Hb FS (α2γβs) in sickle cell disease
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DOI：
10.1006/abio.2001.5358
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发表时间：
2001-11-01
影响因子：
2.9
通讯作者：
Layton, DM
中科院分区：
文献类型：
--
作者：
Ofori-Acquah, SF;Green, BN;Layton, DM
不对称血红蛋白杂合体FS（α（2）γ β（S））的形成在体外抑制血红蛋白S（Hb S）聚合，并在纯合子镰状细胞病中产生胎儿血红蛋白（Hb F）的保护作用。用于分离Hb的常规方法仅揭示对称的Hb四聚体，因为相对于电泳和色谱的分离时间，四聚体快速解离成二聚体。为了深入了解镰状细胞病中不对称血红蛋白FS和其他四聚体的定量分布，通过电喷雾电离质谱（ESI-MS）的新应用研究了溶血产物中Rb亚基的非共价缔合。患者和胎儿血液的质谱显示，以四聚体为主，二聚体和单体亚基丰度较低。ESI-MS分析显示，通过常规高效液相色谱法显示，溶血产物中的杂合Hb AF（α（2）γ β（A））仅含有对称物质Hb A（α（2）β（A）（2））和Hb F（α（2）γ（2））。根据计算的不对称Hb杂合FS的质量，在镰状细胞病患者的溶血产物中鉴定出平均质量为64，558 Da的独特四聚体。在所采用的ESI-MS条件下，杂交Hb物质稳定，可同时测定Hb FS和对称Hb S（α（2）β（S）（2））的比例。血红蛋白FS/血红蛋白S比值与生理条件下的预测值密切相关（r（2）= 0.96）。(C)北京：科学出版社.
Formation of the asymmetric hemoglobin hybrid FS (alpha (2)gamma beta (S)) inhibits hemoglobin S (Hb S) polymerization in vitro and landerlies the protective effect of fetal hemoglobin (Hb F) in homozygous sickle cell disease. Conventional methods for separating Hb reveal only symmetric Hb tetramers because of the rapid dissociation of tetramers to dimers relative to the separation time for electrophoresis and chromatography. To gain insight into the quantitative distribution of asymmetric Hb FS and other tetrameric species in sickle cell disease, the noncovalent association of Rb subunits in hemolysates was studied by a novel application of electrospray ionization mass spectrometry (ESI-MS). Mass spectra of both patient and fetal blood revealed predominance of tetrameric species with dimer and monomer subunits in lower abundance. ESI-MS analysis revealed the hybrid Hb AF (alpha (2)gamma beta (A)) in hemolysates shown by conventional high-performance liquid chromatography to contain only the symmetric species Hb A (alpha (2)beta (A)(2)) and Hb F (alpha (2)gamma (2)). A unique tetramer of average mass 64,558 Da was identified in hemolysates from patients with sickle cell disease in accordance with the calculated mass of the asymmetric Hb hybrid FS. Hybrid Hb species were stable under the ESI-MS conditions employed allowing concurrent determination of the proportions of Hb FS and the symmetrical Hb S (alpha (2)beta (S)(2)). The ratios of Hb FS to Hb S correlated closely (r(2) = 0.96) with those predicted under physiological conditions. (C) 2001 Academic Press.