#ACE2-like enzymatic activity in #COVID19 #convalescents with persistent pulmonary symptoms associated with #immunoglobulin
ABSTRACT Many difficult-to-understand clinical features characterize COVID-19 and post-acute sequelae of COVID-19 (PASC or long COVID [LC]). These can include blood pressure instability, hyperinflammation, coagulopathies , and neuropsychiatric complaints . The pathogenesis of these features remains unclear. The SARS-CoV-2 Spike protein receptor-binding domain (RBD) binds angiotensin converting enzyme 2 (ACE2) on the surface of host cells to initiate infection. We hypothesized that some people convalescing from COVID-19 may produce anti-RBD antibodies that resemble ACE2 sufficiently to have ACE2-like catalytic activity , that is, they are ACE2-like proteolytic abzymes that may help mediate the pathogenesis of COVID-19 and LC . In previous work, we showed that some people with acute COVID-19 had immunoglobulin-associated ACE2-like proteolytic activity , suggesting that some people with COVID-19 indeed produced ACE2-like abzymes . However, it remained unknown whether ACE2-like abzymes wer...