Cell membrane chromatography for the analysis of the interaction between chloroquine and hydroxychloroquine with ACE2 receptors

The recent emergence of the novel pathogenic coronavirus disease 2019 (COVID-19) is responsible for a worldwide pandemic. In sight of this, there has been growing interest in the use of chloroquine (CQ) and hydroxychloroquine (HCQ) as potential treatments. In this study, we use angiotensin converting enzyme 2 (ACE2) over-expressed cell membrane chromatography (CMC) to study the interaction of CQ and HCQ with ACE2 receptor. Both CQ and HCQ were retained on the ACE2/CMC column. Then we analyzed the binding character of CQ and HCQ to ACE2 by CMC frontal analysis, ionic force investigation and competitive binding experiment. Results showed that CQ and HCQ KD values obtained from the CMC frontal analysis method were 8.22(±0.61) × 10⁻⁷ M and 11.70(±2.44) × 10⁻⁷ M. Compare to CQ, HCQ has the weaker affinity with ACE2. The action force of CQ, HCQ and ACE2 is mainly ionic force. CQ and HCQ have different degrees of competitive binding relationship with ACE2. Our study revealed the interaction of CQ and HCQ with ACE2 receptor, which provides new insights for the use of CQ and HCQ in the treatment of COVID-19. Moreover, this biomimetic drug screening method is expected to open the door for rapid targeting and separating bioactive ingredients active towards ACE2 receptor.