Ion Mobility Mass Spectrometry Analysis of Oxygen Affinity-Associated Structural Changes in Hemoglobin

Chae Eun Heo, Minji Kim, Myung Kook Son, Da Gyeong Hyun, Sung Woo Heo, Hugh I. Kim

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Hemoglobin (Hb) is a major oxygen-transporting protein with allosteric properties reflected in the structural changes that accompany binding of O2. Glycated hemoglobin (GHb), which is a minor component of human red cell hemolysate, is generated by a nonenzymatic reaction between glucose and hemoglobin. Due to the long lifetime of human erythrocytes (∼120 days), GHb is widely used as a reliable biomarker for monitoring long-term glucose control in diabetic patients. Although the structure of GHb differs from that of Hb, structural changes relating to the oxygen affinity of these proteins remain incompletely understood. In this study, the oxygen-binding kinetics of Hb and GHb are evaluated, and their structural dynamics are investigated using solution small-angle X-ray scattering (SAXS), electrospray ionization mass spectrometry equipped with ion mobility spectrometry (ESI-IM-MS), and molecular dynamic (MD) simulations to understand the impact of structural alteration on their oxygen-binding properties. Our results show that the oxygen-binding kinetics of GHb are diminished relative to those of Hb. ESI-IM-MS reveals structural differences between Hb and GHb, which indicate the preference of GHb for a more compact structure in the gas phase relative to Hb. MD simulations also reveal an enhancement of intramolecular interactions upon glycation of Hb. Therefore, the more rigid structure of GHb makes the conformational changes that facilitate oxygen capture more difficult creating a delay in the oxygen-binding process. Our multiple biophysical approaches provide a better understanding of the allosteric properties of hemoglobin that are reflected in the structural alterations accompanying oxygen binding.

Original languageEnglish
Pages (from-to)2528-2535
Number of pages8
JournalJournal of the American Society for Mass Spectrometry
Issue number10
Publication statusPublished - 2021 Oct 6

Bibliographical note

Funding Information:
This research was supported by the establishment of measurement standards for the amount of substance funded by the Korea Research Institute of Standards and Science (KRISS–2019–GP2019-0006). This work was also supported by the National Research Foundation (NRF) of Korea grant funded by the Korea government (MSIT) (2019R1A2C2086193, 2021R1A4A1032114) and by the Korea Basic Science Institute (KBSI) National Research Facilities & Equipment Center (NFEC), funded by the Korean government (Ministry of Education) (2019R1A6C1010028, 2020R1A6C103A027). This work was also supported by the National Institute of Supercomputing and Network/Korea Institute of Science and Technology Information with supercomputing resources including technical support (KSC-2020-CRE-0045). The synchrotron X-ray scattering measurements at the 4C SAXS II beamline of the Pohang Accelerator Laboratory were supported by the Ministry of Education and Science Technology.

Publisher Copyright:
© 2021 Springer New York LLC. All rights reserved.

ASJC Scopus subject areas

  • Structural Biology
  • Spectroscopy


Dive into the research topics of 'Ion Mobility Mass Spectrometry Analysis of Oxygen Affinity-Associated Structural Changes in Hemoglobin'. Together they form a unique fingerprint.

Cite this