Electrospray mass spectrometric characterization of hemoglobin Q (Hb Q-India) and a double mutant hemoglobin S/D in clinical samples

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• 作者：Amit Kumar M ; al ; Shveta Bisht ; Vijay S. Bhat ; Patnam Rajagopalan Krishnaswamy ; Padmanabhan Balaram
• 关键词：Hemoglobin Q ; Hemoglobin variants ; Electrospray ionization mass spectrometry ; Tandem mass spectrometry ; Mutant hemoglobin ; Hemoglobin clinical analysis
• 刊名：Clinical Biochemistry
• 出版年：2008
• 出版时间：January 2008
• 年：2008
• 卷：41
• 期：1-2
• 页码：75-81
• 全文大小：1169 K

文摘

The clinical analysis of hemoglobin by ion exchange chromatography can result in ambiguities in identification of the nature of the globin chain present in patient samples. LC/ESI-MS provides rapid and precise determination of globin chain masses.

Design and methods:

Hemolysate of hemoglobin Q-India and hemoglobin S/D/F have been analyzed using ESI-MS. Tandem-MS has been used to establish mutation in α chain of hemoglobin Q.

Results:

The identification of hemoglobin Q-India is readily achieved by LC/ESI-MS, which establishes the presence of a mutant α chain differing in mass from normal α chain by 22 Da. The site of mutation has been identified by tandem-MS analysis of a tryptic fragment encompassing residues αV62-K90. LC/ESI-MS screening has also provide an example of simultaneous occurrence of mutant globin chains containing β6E → V (Hb S, sickle) and β121E → Q (Hb D) variant. Expression of γ_G globin chain is also demonstrated in this sample.

Conclusions:

The site of mutation in hemoglobin Q-India is identified as α64D → H which differs from mutations α74D → H in Hb Q-Thailand and α75D → H in Hb Q-Iran. Mass spectrometric analysis of hemoglobins from a patient and her parents suggests inheritance of mutant β globin genes from both parents.