Substrate specificity of SARS-CoV and SARS-CoV-2 M pro s. To determine the SARS-CoV M pro and SARS-CoV-2 M pro substrate preferences, we applied a HyCoSuL approach. The library consists of

In December 2019, the first cases of a novel coronavirus infection were diagnosed in Wuhan, China. Due to international travel and human-to-human transmission, the virus spread rapidly inside and outside of China. Currently, there is no effective antiviral treatment for COVID-19, therefore research efforts are focused on the rapid development of vaccines and antiviral drugs. The SARS-CoV-2 M pro protease constitutes one of the most attractive antiviral drug targets. To address this emerging problem, we have synthesized a combinatorial library of fluorogenic substrates with glutamine in the P1 position. We used it to determine the substrate preferences of the SARS-CoV and SARS-CoV-2 proteases, using natural and a large panel of unnatural amino acids. The results of our work provide a structural framework for the design of inhibitors as antiviral agents or diagnostic tests.

The prevalence of autoantibodies in multiple sclerosis (MS) patients and their clinical associations differ between various studies. This study investigated antiphospholipid and antinuclear antibodies in 85 patients with multiple sclerosis (MS) and clinically isolated syndrome (CIS) with regard to their association with demographic features, MS specific clinical features and symptoms of connective tissue diseases. Autoantibodies tested included antinuclear antibodies (ANA) with their specificities and anticardiolipin (aCL) and anti-beta-2-glycoprotein I (anti-β2GPI) antibodies. Antinuclear antibodies were more prevalent in MS patients than in controls (63.5% vs. 3.3%; p < 0.01) and in 19% of patients specific antinuclear antibodies were detected. Anti-β2GPI IgM antibodies were more frequent in MS patients than in the control group (20% vs. 3.3%; p < 0.05). The frequency of anticardiolipin antibodies did not differ between MS patients and controls. MS patients seropositive for ANA and extractable nuclear antigens (ENA) had significantly shorter disease duration than seronegative patients (p < 0.05) and a lower disability score (Expanded Disability Status Score; EDSS) (p < 0.05). Anti-β2GPI antibodies were more frequent in patients with secondary progressive MS (SP-MS) and specific ANA antibodies were more frequent in patients with clinically isolated syndrome (CIS) (p < 0.05). The presence of autoantibodies was not associated with the predominant site of neurological involvement or the clinical features of connective tissue diseases.