¦Â37Trp ?#xa0;Cys mutation leads to multiple new hemoglobin species in red cells

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• 作者：Stephen O. Brennan^a ; ^b ; ^{steve.brennan@chmeds.ac.nz} ; Richard I. King^a ; Christopher M. Florkowski^a
• 关键词：ESI ; electrospray ionisation ; MS ; mass spectrometry ; Hb ; hemoglobin ; GSH ; glutathione
• 刊名：Clinical Biochemistry
• 出版年：2012
• 出版时间：February 2012
• 年：2012
• 卷：45
• 期：3
• 页码：259-263
• 全文大小：719 K

文摘

Objectives

To determine the cause of an unusual hemoglobin (Hb) pattern detected during HbA₁c monitoring.

Design and method

Hemolysate was analysed by ESI MS, and individual components purified by reverse phase HPLC. Peptide mapping was used to pinpoint the substitution and DNA sequencing to confirm the mutation.

Results

ESI MS of lysate showed three novel ¦Â chains with mass changes of ?#xA0;83, ?#xA0;51 and + 222 Da. Peptide mapping and DNA sequencing indicated a ¦Â37Trp¡úCys substitution. Reverse phase chromatography showed three new ¦Â globins eluting ahead of ¦Â^A

Conclusion

The new Hbs result from an initial ¦Â37Trp¡úCys mutation (?#xA0;83 Da) followed by oxidation to cysteine sulfinic acid (+ 32 Da) and the formation of a glutathione adduct (+ 305 Da). Despite the hydrophobicity change and the critical location of the side chain on the ¦Á1¦Â2 interface, there was no evidence of molecular instability or altered oxygen affinity, and no clear phenotype apart from discordant HbA₁c.