Probing conformational hotspots for the recognition and intervention of protein complexes by lysine reactivity profiling.

Probing the conformational and functional hotspot sites within aqueous native protein complexes is still a challenging task. Herein, a mass spectrometry (MS)-based two-step isotope labeling-lysine reactivity profiling (TILLRP) strategy is developed to quantify the reactivities of lysine residues and probe the molecular details of protein-protein interactions as well as evaluate the conformational interventions by small-molecule active compounds. The hotspot lysine sites that are crucial to the SARS-CoV-2 S1-ACE2 combination could be successfully probed, such as S1 Lys417 and Lys444. Significant alteration of the reactivities of lysine residues at the interaction interface of S1-RBD Lys386-Lys462 was observed during the formation of complexes, which might be utilized as indicators for investigating the S1-ACE2 dynamic recognition and intervention at the molecular level in high throughput.

Comparison of the clinical features and therapeutics of COVID-19 in cardio-cerebrovascular disease (CCVD) and non-CCVD patients.

Cardio-cerebrovascular disease (CCVD) is a major comorbidity of Coronavirus disease 2019 (COVID-19). However, the clinical characteristics and outcomes remain unclear. In this study, 102 cases of COVID-19 from January 22, 2020 to March 26, 2020 in Xixi Hospital of Hangzhou were included. Twenty cases had pre-existing CCVD. Results showed that compared with non-CCVD patients, those with CCVD are more likely to develop severe disease (15% versus 1%), and the proportion of pneumonia severity index grade IV was significantly higher (25% versus 3.6%). Computed tomography images demonstrated that the proportion of multiple lobe lesion involvement was significantly higher in the CCVD group than in the non-CCVD group (90% versus 63.4%). Compared with non-CCVD group, the levels of C-reactive protein, fibrinogen, D-dimer, and serum amyloid-A were higher, whereas the total protein and arterial partial PaO2 were lower in the CCVD group. Although no statistical difference was observed in the outcomes between groups, CCVD patients received more intensive comprehensive treatment to improve COVID-19 symptoms compared with non-CCVD patients. Integrated Chinese and Western medicine treatments have certain advantages in controlling the severe conversion rate and mortality of COVID-19. In addition, given that COVID-19 patients are usually related to coagulation disorders and thrombosis risk, the application of Chinese medicine in promoting blood circulation and removing stasis should be strengthened.